How we survived the Harbor Freight assembly manual, and modified our greenhouse to withstand New Mexico winds (so far)...

Wednesday, August 1, 2007

Part One: Basic Info, Harbor Freight 10' by 12'

Welcome to my blog about my Harbor Freight 10x12 Greenhouse, most of which was written in the last half of 2007.

Update, October 2011:
In May of  2008, some new problems began to surface on internet greenhouse forums, regarding the polycarbonate panels supplied with this kit. Although the Harbor Freight website has advertised this greenhouse with the following phrase:

"UV coated polycarbonate panels, nearly indestructible"
...several Harbor Freight greenhouse owners in warm climates began reporting early deterioration of the polycarbonate panels. After contacting Harbor Freight with questions about this new issue, and receiving some email replies from them, my personal opinion is there's a good chance the polycarbonate panels supplied with this kit do not have the critical UV coating as advertised on the Harbor Freight website. Or, if there is a UV coating applied to the panels, it's inadequate to protect the polycarbonate from damage when exposed to strong sun/high temperatures. Some variation in manufacturing quality may also exist, since some Harbor Freight owners don't report this problem.

Here's part of an email I received from Harbor Freight customer support, May 5, 2008:

"Our panels are constructed to resist the higher ambient temperatures but
that may differ depending on what state the customers are in. Places like Arizona, Las Vegas, and Texas may cause them to deteriorate faster. Unfortunately our warranty on the parts for this item is only 90 days and we take case by case in determining how we replace the panels for each customer. We know that the panels last longer than that but from a company stand point that is the warranty."
I started seeing some yellowing of my greenhouse panels as early as May 2008 (after about 9 months of exposure to our strong desert sun.) It's now October 2011, and almost all my panels need replacing. The roof is the worst, with holes a few inches apart in the outer wall of the twinwall polycarbonate. Wall panels have fewer holes, but are quite yellowed and brittle. I'll be replacing them soon, and I'll update this blog with photos when I do so.

I thought it best to post about my own experiences with the Harbor Freight panels, so you can take this into consideration. Even with this setback, I still think the Harbor Freight is a great value, since the frame is sound...but I am disappointed about the next (expensive) step I'll need to take as I buy new panels elsewhere. If you're interested, here's a link to a 2008 thread at GardenWeb, which documents this problem first coming to light:
October 2011

Okay, back to business, and the start of my 2007 blog!

Click here to see the greenhouse we bought from Harbor Freight.

It has an aluminum frame, a sliding double door, four roof vents, and 2 ply 4mm polycarbonate panels. It’s 10’ wide, 12’ deep, and stands about 10’3” tall at the peak (taller if you put it on a wooden foundation.) It comes in one box that weighs about 200 pounds. If you're wondering if it will fit in your vehicle, the box is 8 ft long, 25 in wide and 13 inches deep.

Harbor Freight currently sells it for $799, but they put it on sale occasionally. The price makes it attractive; at this time, I don't know of another 120 square foot greenhouse with twinwall polycarbonate glazing in this price range. If you sign up for Harbor Freight's mailing list, they'll mail you flyers, and occasionally these have coupons for up to 15% off. Sometimes you can buy Harbor Freight coupons on eBay. My local HF store kindly honored the internet sale price (even though it wasn't on sale in the store) and they applied a discount coupon on top of that. Nice!

After putting ours up in August of 2007, I think this greenhouse is a fit for people who aren't ready to spend thousands of dollars on a greenhouse kit, and who also have the time, skills, and patience to make the necessary modifications to it.

If you do much reading on the internet, you'll find the HF 10x12 has a reputation among some for being lightweight and unstable in winds, if built only as the manual specifies. (In a very sheltered location it might not require all the modifications we made, but personally I wouldn't take that risk.) When the unmodified structures are exposed to high winds, some people have lost their greenhouses entirely, and others had damage. People who’ve taken the time to share their stories about these heartbreaking failures have helped others pinpoint weaknesses in the kit.

Since its introduction (early 2006, I believe) creative folks have been working on ways to modify the Harbor Freight 10 x 12 kit and defeat the weaknesses. The people who post in the greenhouse forum on Garden Web have been especially helpful, blazing a trail through the murky confusion of the Harbor Freight greenhouse manual, and freely sharing ideas for critical changes to the kit. They have been absolute lifesavers for us, and I highly recommend some reading there. To find these posts, just go to Garden Web and enter "HFGH 10x12" in the search engine box.

Our experience has been that the Harbor Freight 10x12 can be successfully modified to correct the kit weaknesses, with some patience, a little extra work, and a few extra materials. We've never had a greenhouse before, but I'll show you what we did, and you can probably do even better.

Here are some commonly discussed issues with the kit:

Aggravating Assembly Instructions: We think the manufacturing quality of the Harbor Freight 10x12 is actually quite good. We've been pleasantly surprised by the quality of most of the parts, which seem to be well made. There were no misdrilled or ill-fitting parts in our kit. However, the instructions are even worse that we thought (and that's bad!) No photos, tiny drawings, missing info and errors make assembly harder than it needs to be. This is a shame!

Sometimes it’s easier to just look at the parts and figure out how they logically go together, or look at photos of other HF 10x12 greenhouses online. I've included many photos for this reason. You still need the manual, but hopefully our photos will help.

Here’s a link to a PDF file of the manual on the Harbor Freight website. As I write this, the manual in this link is the same as the one in my kit (dated 05/06 on the manual cover.)

Missing Parts: It's a very good idea to check your kit early against the parts list. Some people report missing parts, and this can be a major setback. People report that Harbor Freight says they'll ship the missing part in 6-8 weeks, but I know several people who have waited over a year. This seems to be the biggest customer service problem with Harbor Freight (incredibly slow shipping of parts.) If you find a part missing, and you bought your kit at a local store, you might consider taking the whole kit back and requesting a new one. Or, see if you can convince your local store to pull the missing part from another kit (some people have been able to do that.) Our kit was complete.

Harbor Freight says they're aware of this problem, but they don't foresee the ability to stock all the parts for quick shipping anytime in the near future. (Moral: check your kit.) I think the need for aftermarket replacement parts will increase as more of these units are sold, so I'm hoping they'll focus on this as an area of opportunity for future sales. (Come on, guys!)

Order Extra Panel Glazing Clips Early. They do keep glazing clips in stock, so you can usually receive them in a reasonable time frame. To find out why you need them, you can skip ahead to the "Adding the Panels" section.

Questionable Bolt Quality: The bolts supplied with the kit look like aluminum, but they do stick to magnets, and seem to actually be plated mild steel. They're not great quality, and sometimes the nuts wouldn't thread easily on the bolts without force. On the plus side, they have square heads that bind nicely in the stud tracks, which helps when you're tightening them. Also, the heads are quite flat, so they lay low under the polycarbonate panels on the outside of the greenhouse.

Some people use the kit bolts; others toss them and go buy stainless steel (or other) bolts and nuts instead. We used the kit bolts and bought a few extras as we needed them.

Wrong Bolt Quantity: A really annoying error in this manual lists wrong quantities and lengths of bolts to insert at key points. This means you have to take things apart later to add more bolts. The manual dated 05/06 contains these errors (I'll point it out when we get there.) Earlier kits did not even include enough long bolts to complete the construction, but recent kits seem to be shipping with closer to the right number of bolts. Still, you may well need to buy at least a few that aren't supplied.

If you buy bolts, the heads need to fit in the track of the posts. Some bolt heads are too large. We took a wall stud to the store with us. One kind person posted this specific info for Fastenal bolts that fit:
Bolts: hex head 6mm-1.0x35mm zinc, Fastenal part#1138568, $17.95 for 100
Nuts: 6mm Fastenal Part #1140305 $3.40 for 100

You can also add bolts after assembly by using T bolts (from Fastenal or Charley’s Greenhouse Supply.) Or, some people just take a grinder to a regular bolt head to make it fit. In a pinch, we also used 3/16" carriage bolts, clipping off part of the head with a bolt cutter.

Changes To The Kit: To their credit, Harbor Freight has revised the manual several times to correct some errors (mine is dated 05/06.) Also, some parts have been changed or improved from one kit to the next, so they may not exactly match the manual. This makes it harder to be helpful in this blog, since your kit might be slightly different from ours. Some of the errors mentioned here will probably be corrected in future manuals and kits.

The photo to the right shows the tool we found the most useful for tightening the bolts...a 10mm nutdriver.

And here's a photo of the little wrench that Harbor Freight includes with the kit. Other than making you smile, it's not helpful. (I'm pretty sure the Chinese manufacturer only includes these to prove they have a sense of humor.) Actually there were two in our kit, but that did not convince my husband and I to use them.

Click here to go to Part Two: The Foundation, the first modification we made to the kit.


solong4now said...

Thank you so much for doing all this documentation, it certainly made my construction go along much better and I did it all myself. The only thing I would add is just the advice, and you touched on this, to attach the angled supports to the corners right away. since I built this on my own I had no one to help hold things but attaching the cross supports, loosely, everything had enough support to build upon. Even doing the roof, and I can't imagine anyone doing as the manual says building it on the ground and then putting it up. I was able, with help using a pole to hold up the other end of the roof peak spanner as I attached one side, to attach the roof solo.
But great job on this blog!

rcarrcrew said...

how long did it take you to completely assemble your greenhouse?

mudhouse said...

Hello rcarrcrew,
A good but hard question! We made no attempt to complete the construction quickly, and worked on it as we pleased. Stopping to document and photograph the tricky parts (for this blog) took a lot of time. Also, we halted construction at several points to do things that others do later; for example, we did the rough plumbing and wiring, and built the benches and greenhouse floor before we finally put in the panels. (It made sense to do that because our climate here is so warm.) It was probably about three months total from the time we started to having the exhaust fan, thermostats, shadecloth, and sink in place, but we weren’t trying to hurry at all.

A lot depends on how complicated your foundation is. If you live in a very cold climate, you may need a more sophisticated foundation than ours. Some very conscientious folks spend weeks preparing and building the foundation alone.

It took us about 1 ½ days to put in all the panels, but that was because I insisted on adding weatherstripping on all four sides of each panel opening as we went, and we screwed each panel down as we went. (I don’t regret adding the weatherstripping.)

Now that we know exactly how the thing goes together, my husband and I think we could probably erect another Harbor Freight 10x12 in three long days...IF the foundation was already built, with no plumbing, electrical, etc. However, that’s only because we’ve already built one.

In case you’re asking because you’re considering hiring help, I’ll share online friend hired a handyman to erect the greenhouse for her, hoping the basic construction could be accomplished in a few days. Long story short, it didn’t work that way. A series of handymen started the job and never returned (once they saw how confusing it was, when looking at the manual “cold.”) The basic greenhouse shell was finally completed with the help of a kind and patient neighbor, some time later.

Any greenhouse is an ongoing project, since you often don’t know what you need to add, until you see how it’s working (or not working.) It’s so much more than just the initial walls, and the date to declare it really "finished" is somewhat of a moving target! I hope this very rambly answer is a little helpful.

solong4now said...

Hello rcarrcrew,
I'll throw in my two bits as I concentrated on just the building without getting too much into the extra's. I posted a few pictures from my effort here
The time frame building my greenhouse was one weekend to make the base. I did my base as a wood frame, the ground was uneven so I had a bit of digging to do and then I attached a tarp on top of it loose enough to sag to the ground and I loaded a 1/2 ton of pea gravel on top of the tarp. It took almost 2 weekends to build the frame which I was able to do completely by myself though I had to get creative to do the roof. The panels I did sporadically as I prepared them with tape on the ends. I also drilled holes to attache them to the frame and did some of the other structural enhancements. All in all it took about a month of spare time while working 50-60 hour weeks.
Now that it's winter in Chicago, I'm storing all my outdoor potted plants which normally were in the garage.
My only word of caution is to think long on where you are building, the 10x12 is very big and will block your view even from 2nd story window.


mudhouse said...

Howdy solong4now! Thanks so much for adding your comments here, and for the link to your good pictures. I appreciate all of your input, including how long it took you to build your greenhouse. I suspect many folks wonder about that, but I struggle with that question since we were as slow as molasses in building ours.

Lovely gardens around your greenhouse...mine looks barren by comparison.

Peter Breslin said...

wow, this blog is an incredible resource! I've been tempted by the comparatively low price of HF kits. All I can say is you guys are absolutely awesome and show the patience and problem solving skills of saints. It seems it may actually be easier and cheaper to custom design and build one's own greenhouse....

mudhouse said...

Hello Peter, and thanks! I've seen some posts about folks locating salvaged components (doors, windows,etc) and building their own greenhouse for a low price, so I know it can be done. This HFGH was a good introduction for us, though, since we frankly would not have known how to design a greenhouse on our own (never having owned a GH of any kind previously.)

Not really sure if a home-built would be easier than this kit...probably some types, like a hoop house, would be. But generally I think most greenhouses end up being a good chunk of work regardless. Good thing gardeners are generally stubborn optimists!

We agree we'd be more comfortable trying to scratch build a greenhouse now that we've owned this one for a few years. But before this kit...I'm not sure I would have had the courage to leap into unknown waters!

greenwall said...

Please check Multiwall Polycarbonate panels made by Polygal. they come with 10 years warranty.
In the USA
In canada

3Leeds said...

Is there anyway of finding out if the panels are from There was no documentation about the panels in my kit, not even if the UV coating was on one side or both and HF had no clue. I live in Illinois so hopefully will not have the degradation issue but if I do it would be nice to have a warranty backup.

mudhouse said...

Hello 3Leeds,
Your lack of answers from HF fits the experience of others, and fuels my suspicion that no UV protective coating has been applied to either side of the HF twinwall polycarbonate panels.

The Harbor Freight greenhouse kits are manufactured and packed in China, and it's my belief the poly panels are also manufactured in China. I hold out little hope they're manufactured anywhere else.

When I contacted Harbor Freight back in May of 2008 about the panel deterioration problem, this was part of their reply:
"Unfortunately our warranty on the parts for this item is only 90 days
and we take case by case in determining how we replace the panels for each customer. We know that the panels last longer than that but from a company stand point that is the warranty."

From my looking around on the net, I find many reputable manufacturers of twinwall polycarbonate offer respectable warranties, but Harbor Freight's poly panels do not. I'll definately take warranties into consideration, as Greenwall suggests, when I need to replace my panels.

3Leeds said...

When I was looking into designing and building my own greenhouse that was going to be smaller (8x8x8 aprox) the cost of UV polycarbonate sheets added up to almost $500. I don't hold much hope for the quality of my HF kit but I was able to get it for $570. I am happy with the frame and it wasn't too bad to put together. I think it will last quite a few years and if I have to replace the panels I will do just the top with high quality sheets and something lesser on the sides if and when they need it.

mudhouse said...

Exactly! That's the way I look at it too. Even with the eventual panel replacements in my very sunny climate, my HFGH has still been a very good value for me. The foundation, frame, plumbing, electrical and benches are all secure, and I'll decide how many and which panels to replace as time goes by. Here's hoping you'll be able to have many more years with your panels before dealing with your somewhat kinder climate!

inthralled said...

This has been a great help. Like you I have the base sitting on 4X6 pressure treated lumber. I tried to bolt down the base before assembly of the sides but found I would warp the base and take it out of square. I see in your pictures that you have added a wood strip to the inside of the base. Can you tell me more about what you did with the base? Thanks John Port Orchard, WA.

mudhouse said...

Hello John, I'm out of town right now, but will reply on Tuesday. Also, you're welcome to email me at, and we'll be happy to do our best to help.

mudhouse said...

Back again, and I’m sorry for the delay. We’re not sure why attaching the metal base to your wooden foundation would warp the metal base out of square, unless your wooden foundation is not quite level, and/or out of square. We took a long time to make sure the 4x6 foundation was level and square before adding the metal base; checking, readjusting the wood, and adding or removing soil as needed to make sure it was flat and level. Once it was level and square, we anchored it with the rebar pieces as shown in the photos, and then checked for level and square again.

After we had the wooden 4x6 foundation square and level and anchored, we also added some short diagonal braces inside each corner, made from 4x4’s, just to make the wooden foundation less likely to move as the wood dried over time (the lumber we purchased was pretty wet.) Those also show in the photos in Part Two, The Foundation.

Also, we used some blue polyethylene sill insulation in between the pressure treated lumber and the metal base (shown in Part Two, The Foundation) and that very slight cushioning may have helped compensate a bit for any slight natural waviness of the wooden surface. After taking these steps, we didn’t have any problems with the metal base being pulled out of square as we attached it to the wooden foundation.

The 1” thick cedar boards you asked about were added to the interior of the base much later (Part Five, Modifying the Frame for Strength) after the greenhouse framework was completed. They didn’t have anything to do with getting the base square or level. Several GardenWeb forum members suggested adding boards or metal plates to the upper and lower lip of the C-shaped metal base to prevent it from flexing as wind pushed on the greenhouse walls. We also liked the idea of filling the void with some insulation before adding the boards…and we thought it looked nice as well. Basically those boards just covered up the open void in the metal base, preventing dirt and water from accumulating in there, and add a bit of rigidity to the base.

Let me know if this doesn't answer your question, and we’ll be happy to try to help!

Unknown said...

Wow! What a treasure to find your blog. I own a small company and we are planning to combine two of the 10x12 green houses to create one 10x18 tradeshow booth to display our backpacks. From looking at the manual it appears that we could add one six foot side section to make it 18' long.

I was curious if you thought this was a realistic option? We plan on building the green house in our warehouse, label it, take it down, crate it up and then build it again at the trade show. Do you think the green house will come down and be able to go up again? Ideally we would use it for several trade shows so it would be built and taken down many times.

Your thoughts would be greatly appreciated.

solong4now said...

Hello Bart,
Well this is a fairly labor intensive project but I suppose if you have a team working on it...
As far as putting a 10 x 12 and part of a second one together to give you 10 x 18, I suppose it can be done making some modifications to it.
Part of what has made mine so sturdy has been the permanent foundation I created.
I've done trade shows and typically a wide open area is what you want and this would be closed up though you might get away without putting all the corraplast panels in. Traffic would also be kinda stymied by the relatively small opening and having to step over the metal frame. Part of what has made this a good greenhouse has been the additions that make it a more permanent structure.
I'm sure there are plenty of modifications you could make to it but my trade show experience would shy me away from using a greenhouse much less this kit as the frame is all very narrow aluminum rails and there isn't much hiding place for labels, even the tiny ones that it comes with stand out.
What kind of back packs do you sell that made you think a greenhouse would be a good showplace?

Unknown said...

We like the idea of being separated from the rest of the trade show. We were planning to build the entrance at both ends of the booth for better access. By using the two green houses we were hoping to get rid of the back wall and use both doors. Having to step over the metal frame is an issue. We were hoping we could figure out a way to get rid of that section and add a horizontal brace at the bottom that wouldn't hinder the entrance much. Does the door slide along the metal base? That would be an issue.

The backpacks don't have anything to do with green houses we just like the look of it and will make some visual modifications.

mudhouse said...

Hi bartco4,
I share some of solong4now’s concerns. My husband and I built art fair booths for years, and I agree a unique product background is beneficial. Still, we’d worry about the time and effort to build and tear down the structure within the time restrictions of a trade show. I think you’d need a crack team of very capable and patient folks to pull it off, since it’s definitely not designed for fast or easy assembly.

The doors do slide on the track at the bottom. An even bigger problem is the steel C-shaped base that the aluminum frame sits on. It’s about 5” tall, and the aluminum door track sits on top of that, so it’s a huge step-over. I agree with you...having people step over the metal base would present an unworkable safety hazard at a trade show. Removing any portion of a major component like the metal base would cause the frame to be less stable without serious reworking. The greenhouse frame is frankly a bit wobbly anyway, even when built as per the kit, which is why we Harbor Freight greenhousers have to go to the trouble of the extra bracing modifications, and building a very sturdy foundation on the ground.

Some greenhouses are strong enough to support the weight of items hanging on the frame, but I’ve never liked hanging much weight on the lightweight Harbor Freight frame. I personally hang very few items from my greenhouse walls or roof (even after adding the EMT braces for stability.) I don’t know if this is an issue with your backpacks. We were in the habit of considering wall strength for product display because our own products (handcrafted iron) were heavy.

Be aware that the aluminum alloy used by Harbor Freight is quite soft (softer than the aluminum stock sold at the big box stores, for example.) This means that care would need to be taken during set up, tear down, and shipping; if one of the long aluminum framework pieces was badly bent in transport, you could be in a pickle. Getting replacement framework parts from Harbor Freight is generally an exercise in frustration.

Anything is possible with time, determination, and money, but we wonder if the work involved in re-engineering the greenhouse into a display booth would be worth the final return in increased sales. I like thinking outside the box, and you’re the best judge of the right display for your products…but we think this would be a pretty challenging conversion. I hope this is a bit helpful.

Unknown said...

THis weekend I took a long look at my greenhouse wondering how it could be used for your purposes and what modifications would need to be made.

First off I think you would get away with not using the steel 'C' channel frame for the base but what you would have to do is create a new base platform to attach the framing to. I'm thinking you could do this with a plywood foundation the same overall size of the 'C' channel base. Since the greenhouse mostly just sits on top of the base and only really attaches with little clips, you could attach the bottom of the framing directly to the plywood. However you would need to create the base out of several sheets of plywood that would need to be connected. Also in the corners they are connected but you could probably work something out for that as well. If your plan is to have opening on both sides you might as well leave the doors off as they don't really add anything to it structurally.
I just caution that you will really need to get the kits and work on it to see if it would work to your needs and be prepared that it may not. You would also need to do some of the extra structural additions that we've described to have it be strong enough to hang much off the sides.

I'd be happy to take photos of key areas you would need to consider if you like.

Unknown said...

Hi Everyone,

Thanks so much for your responses. We bought one green house and I'm preparing to put it up in our warehouse...we'll see how it goes. I'll order the other one if it seems like it will work. If not I'll box it up and use it later for it's intended purpose.

I like the idea of leaving the doors off, that should help a bit.

Thanks again and I'll post an update when I make some progress.

mudhouse said...

Good deal Bart. We will look forward to hearing how things work out!

weiweilee said...

I am setting up a 10x12 ft4 Greenhouse, it is impossible to do it without your excellent document, really appreciate your efforts to share your experience.

I am adding clips to the polycarbonate panels, I can't figure how to do it, do you have a few photos that will show me how to use the clips?

mudhouse said...

Hello weiweilee,
The clips can be a little confusing at first. Try looking ahead to the last part of my blog, Section Seven, Greenhouse Enhancements. Scroll down the page to the part that says "Aluminet Shade Cloth Screen Panels". The fifth photo in that part shows a close up of an installed clip (although it's holding a screen panel in place, and not a clear polycarbonate panel.)

The central curved part of the clip ends up on the outside of the panel; the two middle smaller curves end up underneath the clear panel; and the two ends of the clip snap into the folded metal edge of the vertical frame pieces.

You might compare my photo to illustration C on page 16 of the Harbor Freight manual, to see if that helps.

If this is still clear as mud, feel free to send me an email directly at, and I could snap other photos to send in an email to you. Hope this helps!

Anonymous said...

I have rebuilt and reinstalled the windows (vents) three times and still do not get them to "hinge" properly. The fit, but open opening shift at the crown. Any tricks? I am just about to bite the bullet and hinge them!

mudhouse said...

Hi Nora, based on your description, I'm not clear on what's happening with your vents...but I do admit they are probably my least favorite part of the Harbor Freight greenhouse.

Mine opened and closed fine, after some fiddling with the fit, but I found a strong wind could lift them open an inch or so, even when they were locked down in the tightest "closed" position. Because my winds can be especially wicked here, I eventually just wired them shut, and use my doors, side panels (replaced with screens) and exhaust fan to ventilate during hot months. Also, I had to use a small ladder to open and close the roof vents, and I worried about taking a nose dive into a bench of prickly cacti.

You might consider posting at the GardenWeb greenhouse forum, to see if other Harbor Freight owners recognize what the problem you're having (also, you can post a photo there, which often helps.) You can copy and paste this into your browser to reach the forum:

Comstock said...

This is an incredible resource! Thank you so much for the many hours this site must have taken. I just started construction of my greenhouse today and plan on following all your thoughtful ideas. I actually poured a concrete perimeter foundation for my project. I am very excited to see it come together. My 7 year old son is my helper and very proud of what we are accomplishing- his first big project. Thanks again. Erik

mudhouse said...

Thanks, Eric. With a good foundation and such excellent help, you should be well on your way to enjoying your new greenhouse. Best of luck!

The Greenhouse Guy said...

Hi again mudhouse, a few months ago after my rant about all the free advertising HFGH gets on gardenweb you suggested instead of whining I should create a website and use it to sell my greenhouses. Thanks I took your advise and traded a 10x40 foot greenhouse to a guy that makes websites and he was able to create exactly what I wanted. I still sell mostly on the seattle and portland craigslists locally but use the site as a reference tool to send potential customers to. When they call back they know my greenhouses and are usually ready to order. I also tried growing for market magazine and google adwords and have now started shipping them to a few places around the country at a price and structure that I thinks puts HFGHs to shame. So feel free to check out my site and thanks again for the suggestions. Steve

mudhouse said...

Congratulations, Steve, and best of luck with your nice website!

Art said...

I'm 62 and it took a little longer for me to assemble, it went well and in 4 weekend I had the cement poured and the unit was standing, electric and drain were install 2 weeks before to the erecting the unit. I cut the metal bast in half and secured it to block stem walls, an into slab. I order clips and exter bolts. My orchids are now in unit and growing. All things considered it went well but spend some time on the early planning for water and slab and maybe stem walls and bech materials where water shouls be placed alondg wit drain even if just into a plastic barrel with a shot leach line off it. wish I could post pictures to site to show how unit wa connected to block and slab with stem walls.

inside looking out said...

I just bought this greenhouse, I want to put it on my deck. i want to put the opening to my sliding glqass doors, need to know if i can put a door in the side to get in from outside. Also... i live in upstate ny and the snow is just plain stupid. is the pitch of this greenhouse steep enough to shed the snow. How can i stiffen this up so it wont collapse on me. if i cant do this i will take it back before opening it.

mudhouse said...

Hello "inside looking out":

Some folks in the greenhouse forum at GardenWeb are cautious about placing a greenhouse on top of a deck. If the deck is wood, you may be inviting problems with wood decay, mold, etc. in the damp environment of a greenhouse. Secondly, your deck floor may or may not be airtight; if you’re planning to heat the greenhouse during cold winters, it may be difficult.

I don’t know anyone who has added a door to the side of the greenhouse, but I’m sure it could be done, with time and money. I think you’d have to create your own solution from scratch, but if you’re creative and handy with building, I imagine you could figure out a way. Each panel in the side of the greenhouse is only 1' 11" wide, so if you remove a panel to make an opening for your new door, you won’t have a standard size door opening (meaning you’ll likely be building your own door somehow.)

I have no experience with snow on my greenhouse, but from my reading, snow can create problems with Harbor Freight greenhouses. The weakest point is probably the center of each aluminum roof stud. I would not count on the roof shedding snow by itself. I think a heavy wet snow is risky, without extra bracing.

There are two threads in the GardenWeb greenhouse forum posted by another HFGH owner (rosepedal) showing how they reinforced their greenhouse to withstand Wisconsin snows. To access these threads and photos, copy and paste this URL into your browser window, for the GardenWeb greenhouse forum:
and do a search for “snow load brace” and a second search for “midwest snow storm”.

Because your situation is a little challenging (deck, heavy snow, adding doors) you might consider posting some of your questions to the GardenWeb greenhouse forum as well, to see if others can be more helpful.

mudhouse said...

Hello Art,
Congratulations! Your foundation and greenhouse sound wonderful. Nothing prettier than a greenhouse full of orchids (I will admit, even prettier than a greenhouse full of cacti.)

I feel certain that your methods for attaching the HFGH to your block stem walls and slab would be helpful to others. You might consider posting a thread with your photos to the GardenWeb greenhouse forum. There are a number of Harbor Freight greenhouse enthusiasts that read there, and your techniques would probably be interesting to greenhouse owners of all types.

Good job and happy growing!

Unknown said...

Hello. We are from Indiana in an area that receives high winds across farm fields nearby. We constructed our 10 x 12 greenhouse in July 2009. It took my husband and I a solid day and a half. We mounted it on a 12 x 14 foot wooden deck. We then placed foam interlocking flooring inside (which is great on the feet and back!). In reading the posts, we have agreed with many. Our dilemma comes mainly in where our greenhouse is! Strong winds came a few weeks back and over 85% of our panels and a portion of the framing was stripped from it! The metal frame is damaged where the nuts are secured. We are perlexed, but had a feeling this would happen with such simple construction. We are thinking of solid polycarbonate panels or even glass with a wooden frame ($$$$$!!), but with our climate, we feel there are few options.
Any suggestions??

mudhouse said...

Hello Kirsten,
I'm very sorry to learn about the loss of your HF greenhouse. You didn't mention if you were able to modify it during construction to withstand heavy winds, using the methods outlined in this blog. Without these modifications, your experience with the Harbor Freight greenhouse is unfortunately not uncommon. However, with the modifications outlined here (gleaned from many wonderful posts at the GardenWeb greenhouse forum) I haven't personally heard of folks losing their HFGH to heavy winds.

My only greenhouse experience is with my HFGH, but I think you'll find the GardenWeb greenhouse forum a very helpful place to read about a variety of structures made from different materials. Many folks post there with a much wider range of experience than I have, and I'm hoping they will be able to better answer your questions. Best of luck to you!

Anonymous said...
This comment has been removed by a blog administrator.
Unknown said...

Thanks for all the documentation and pictures. We could not have got as far as we did without it. We are trying to install the windows in the roof. There is a big gap at the top and bottom of the panel. Do I put weather stripping in there? Do I screw in the window panel to the frame surrounding it? Do I clip the panel in on the windows? Sorry, I am not able to figure this out. Also, how does on put the clip in?

Thanks in advance.

mudhouse said...

Hi Mark,
I had the same problem (see part four of this blog, and scroll down to "The Loose Window Problem." Some kits apparently don't have this problem, but some do. My window poly panels fit well side to side, but had at least 1/2" play from top to bottom. I could not find any way to screw the panels to the window frames, nor could I find any way to apply clips. I tried to live with this, but the poly panels moved in high winds, and one even came part way out in a storm. I solved this problem by caulking the poly panel into each window frame (do this before you install the windows in the roof.) I used clear silicone caulk, and so far, I've had no more problems with the window panels moving within the frames.

We uninstalled the window frames to do this caulk repair, but I made one goof...I did not make a note of the order the windows were installed. When I put them back, after caulking, I managed to put some windows back in different locations...and as a result, they never fit or operated quite as well after that. At that point, my roof panels were installed, and screwed down, so the frame could not be loosened to re-finesse the fit. So, if you have already installed your windows, and plan to remove them to do the caulking fix, be sure to number them and reinstall in the exact same order (it will save you some bad words.)

These are the only panels I've secured with caulk in the entire greenhouse. I like the flexibility of being able to remove removing screws and clips...but the window panels represent a special problem, when they are loose in the frame.

Sorry you have the same problem I did. Let me know if I can be of any further help.

KathyO said...

Hi ya'll,
my hfgh will be here in a few days. I really really really want to paint the aluminum GREEN! My hub thinks I can't and he is usually right, but I thought I would check with you who might know! I would imagine I would have to do primer, but is it even possible? I am in Oregon, not a lot of heat, but lots of wet! Thanks for your blog on building the gh, we have printed it off and will follow your advice!

Anonymous said...

I still can't figure out how to install the clips. I've seen the close up picture of the clip installed, but can't figure out how to make it happen. All I do is dent the panel and scratch the frame. Can someone please help and try to explain it?

mudhouse said...

KathyO, I don’t have any experience in painting the HFGH frame. At the risk of causing marital discord, I do believe that aluminum can be painted; if you Google “can aluminum be painted” or similar phrases, you’ll find many folks asking the same thing. Priming seems to be recommended by many, as you said.

I’m not sure how well the primer and paint would adhere to the new aluminum on places receiving lots of wear (door frames and threshold, for example) and I’d avoid painting the interior tracks of any parts receiving sliding components (top and bottom of the door) lest it affect their smooth operation.

I guess it’s possible that some scratches might occur during the installation process, and you’d also be looking at silver bolt heads against the green frame, unless you painted the bolt heads green, and touched them up after installation (which makes me tired to think about.) Not sure if that’s an issue?

I remove the south panels on my greenhouse to replace with screens in the summer, and I notice that taking the panel clips in and out repeatedly has scratched the frame, which would be noticeable if I had painted the frame. This may not be an issue for you, either.

You might gaze at the box of components when it arrives, to be sure you have the energy required to tackle priming/painting all the parts before you tackle construction. It sorta sounds like a lot of work to me, but then again, most hobby greenhouses exist purely for the pleasure of those who own them. Nobody knows what makes your heart happy better than you do. We also installed a mosaic potting bench in ours, which surely was unnecessary work, but I love it.

If you’ll need to cover much of your greenhouse exterior with shadecloth eventually, you may find that the frame color isn’t as large a design detail as it might seem now. Much of my GH is swathed in Aluminet now, but we have much more sun than you folks.

Maybe someone else will chime in here with more experience in painting aluminum. I hope you have lots of fun with your greenhouse, regardless of what you decide to do!

mudhouse said...

Hi Mark,
The clips are pretty simple, but amazingly hard to explain using words. I think you’ve already found the closeup clip photo in Part Seven (Aluminet screens). Maybe the following description will help, in addition to that photo.

Of course, you’re standing outside the greenhouse, since the poly panels sit on the outside of your greenhouse frame. Generally, the two ends of the clip (let's call them "feet") are captured inside the curve of the aluminum track. The center part of the clip presses down on top of the poly panel, while the two clip feet are caught in the aluminum track, to keep the clip center pressed down on the panel. The two small v-shaped bends in between the feet and the center (let's call them "shoulders") slip a bit behind the panel edge. Unfortunately my clip photo in Part Seven doesn't illustrate this very well, since my Aluminet screen frame (the glossy white part in that photo) is a bit too fat for the clip "shoulders" to slip behind. But, they really do go behind the edge of the thinner poly panels, as shown in illustration C on page 16 of the Harbor Freight manual.

One trick I've learned is to put the clip in place this way...stick the bottom "foot" in the track, and place the center part of the clip on top of the panel. The last part to click into place is the top "foot". I find this the easiest way, although others may have their own way. If I want to take out a clip (and I do that all the time, to put my screens in) I just take a screwdriver and use it to gently pop the top "foot" out of the track. The clip falls right out once I free the top "foot."

One other thing...when learning, try using on one of the wall studs that is not a corner post. I find the clips fit a bit tighter in the tracks in the corner posts...because the flange that catches the "feet" is just a tad smaller on the corner posts, so they require a bit more effort to click into place. Try learning on one of the other wall panels.

All of the above sounds a lot more complicated than it is. If this is still confusing, feel free to send me an email at and I’ll try to do a better job of helping.

Buck said...

Frist k you for taking the time to do this blog. I am about to start my install and I think I should make a run to Lowes before I start. Your recommendations are very germain here in Virginia, where we can have winds upto 60MPH is normal weather conditions. Above that I want to be in my cellar.

Unknown said...

Hello Mudhouse,
First I would like to thank you for your bolg and I haven't even gotten past the first page yet. My wife (and I) have just bought the HFGH and found your site honestly hours before we did. After looking over your blog we have already seen many thing that we will need to do and some great suggestions from many people yourselves included. I am going to do my best to photo and document as I go on my own blog to hopefully help others that come along. I look forward to reading the rest of your blog as I too start my HFGH adventure.

Terry a.k.a. Wingenut

DA said...

Hi Mudhouse,
I am currently building the HFGH. I have the base installed with 4" x 6" as you suggested. I am in Georgia. My concern is the strength of the base. When sunk in the ground there is dirt and gravel to support the sides. When mounted on top of the foundation there is none of that. Is it stout enough? I noticed you have some red colors boards bordering the base on the inside. Do those boards provide any support to the greenhouse above? Just a thought, but what about installing the "floor plates" right to the foundation and skip the base? Seems it would be much stronger. Your thoughts?

mudhouse said...

Hello DA,
When the 10x12 kit first came out, there was concern among some that the c-shaped steel base might flex, so some advised adding small metal plates with screws that bridged between the top and bottom of the "C". Others suggested stiffening the base by adding a wooden board, screwing into the top and bottom of the "C", on the interior, and that's what we did, to be safe. Before we did so, as the pics show, we also cut strips of insulation and put them inside the hollow space in the base. (Of course this isn't critical at all...but we had the extra insulation, so what the heck.)

I have heard of a few folks who didn't use the steel base, because they thought the steel might eventually rust. But then you have to re-engineer a way to attach the wall studs to your wooden base, since the Part 47 Hold Down Connectors are designed to slip around and grasp the top lip of the "C"-shaped base. If you eliminate the steel base I don't see how you can use the Hold Down Connectors, so you have to come up with another solution for anchoring the wall studs to the base.

Frankly we think it's a lot simpler to use the steel base included, and we don't think there's a down side. We have not had any indications that doing so weakens the walls, and I haven't heard of anyone (in various garden forums) who has experienced problems with the steel base on this kit. We also haven't had any rust develop on ours, after four years (admittedly, we are in a dry climate.) It still looks great.

We added the cedar boards (stained with redwood stain) to the inside of the base because it wasn't hard to do, and we were being cautious, and we noted that others had done so. In retrospect, I don't think it's all that critical, although it does likely stiffen the base a bit, to prevent it from flexing, when big winds push on the greenhouse walls. (We do get really bad winds here, every spring and summer, and we tried to do anything we could during the build to give us extra strength, even if it only added a small bit of strength.) We also simply liked how it looked on the inside of the greenhouse (nice wood always looks and feels warmer than bare steel.)

I hope this helps. If we built another Harbor Freight, we would most certainly use the steel base that comes with the kit. We would probably add the interior wooden boards again, partly for looks, but wouldn't be too worried about omitting those, either.

Good luck with your build!

DA said...

I'm just getting the walls up and all is going well until I got to the place where parts 24 and 25 join together above the opening. I've successfully attached vertical supports 28 and 29, but I can't get 24 and 25 to come together. Are my pieces not correct? The bolt holes line up just fine, but because of the shape of 24/25 they will not fit flush together. The shape of the parts won't let them join together well. Neither the manual or your documents seem to address this issue. I have photos but don't know how to get them to you.



mudhouse said...

David, according to my notes scribbled in my manual (probably copied from some helpful soul on the GardenWeb forum) the front ceiling plates, parts 24 and 25, can't be connected together on their own. The manual is not very clear on this, and you have to really peer at the confusing tiny illustrations to catch it. You have to use part 27, the right door rail, as a splice plate. Use the two holes near the center of the right door rail (Part 27) to join the front ceiling plates (24 and 25.) You can also attach the left door rail, part 26, to part 24 at the same time.

In my manual (which might have changed slightly from yours) the best illustration is at the top of page 7, step 3 under Assembling the Outer Frame.

If this doesn't resolve the problem (and with Harbor Freight manuals, you never know!) feel free to send me pics and/or email me directly at, and I'll be happy to try to help further.

mudhouse said...

Also, David, thanks for pointing out a potential stumbling place, I'll try to update the blog to make this more clear for others!

snwplwdrvr said...

Thanks so much for sharing your experiences!! I am going to Harbor Freight tomorrow to buy mine. Has anyone built one in a area with alot of snow fall? will it hold up?

mudhouse said...

Snplwdrvr, folks do build Harbor
Freight greenhouses in snowy parts of the country, but there have been some reports of roof damage from heavy snow build up. The aluminum frame of the HFGH kit is not known for being very strong when stressed (one reason I am such a fussbudget about the modifications listed here for withstanding heavy winds.) There have been some threads in the GardenWeb Greenhouse Forum showing how folks have modified their greenhouses to withstand snow load. Hang tight, and I'll post back tomorrow with a list of links so you can see what others have done. Back soon,

mudhouse said...

Hi again snwplwdrvr, I'm back.
As I mentioned above, there have been some forum posts about wet, heavy snow causing roof damage to the HFGH, so some folks in snowy areas add additional interior bracing, specifically to support (roughly) the centers of the roof studs. This is another area where each HFGH owner applies their own creativity, so I'm listing some links below so you can see what different folks have done.

Polcat has a very handsome solution for snow load bracing:
Polcat's snow load trusses

Rosepedal's threads about snow load bracing:
Snow Load Brace...
Midwest Snow Storm

Web4deb has a wonderful blog about building and modifying the HFGH in amazing ways. This part of the blog mentions modifications for snow load: web4deb's snow load modifications

Other threads about snow load:
Snow, how did you make out?
HFGH 10x12, need roof studs (This one about a roof failure)
Harbor Freight Aluminum Greenhouse, need advice for Michigan

In addition to roof support, some folks in snowy climates find that the sliding doors can freeze shut, especially in wet icy conditions. This has only happened to me once in 4 years, but I live in a warm climate. Ice accumulated in the bottom door track and nothing moved for 18 hours (I was pretty sure wrenching the doors free would damage the soft aluminum frame.) I have never caulked my panels in place, so I always know in a worst case scenario I can remove a side wall panel and enter the greenhouse that way, in an emergency.

Some folks in icy climates have even engineered ways to replace the sliding HF doors with hinged storm doors, if the frozen sliding doors continued to be a frequent problem. I have seen a few posts in the greenhouse forum in GardenWeb with photos. Doesn't look like a super easy adaptation, but anything is possible with these kits, with a little time and determination (and a few extra dollars.) Here are a few links to photos:

Yorkie89's door replacement photos are in this thread:
Ripping out the doors...HFGH

Web4deb also made the kit sliding doors work as hinged doors; scroll down to
New doors on the greenhouse

I hope this is helpful...

snwplwdrvr said...

Very Helpful!! thanks Sheri!! I will keep you all informed of my progess

MagicBill said...

I have been reading this blog and I'd like to thank all for their contributions. I purchased a 10x12 HFGH kit several years ago but never installed it. I have since moved and the rear lot needs to be terraced before I can even attempt to build the kit. I will take the modifications into suggestion. I noticed a lot of people complained about the flimsy aluminum frame. There is a product called 80/20 ( and they offer a T-slot frame which is very strong and lightweight. The panels might be able to slide into the T-slots without modification. They also make other framing solutions but I have worked with the 10 series T-slot framing which is 1-inch square and I can assure you it is rugged stuff. I'm using it in another application.

I hope this helps and keep up the good work!


mudhouse said...

Thank you MagicBill, I agree this blog has been greatly enriched by many who have added comments here. That looks like a good product to keep in mind for future creative projects.

We don't find the frame to be too flimsy, after the modifications suggested by others (and repeated here.) I do think the aluminum in this kit is a softer alloy than some aluminum (softer than the bar aluminum sold in the box stores, for example.)

Best of luck with your greenhouse, I hope you enjoy building and using it!

Anonymous said...

Can this kit be built without putting in the panels? Or are inserting the panels necessary?

I was thinking about marshaling the support of a mechanical engineering friend of mine to get it up, and then come back later to install the panels afterwards.

Is this possible or even recommended?

mudhouse said...

Yes, that's generally the process, the frame is built first and then the wall and roof panels are inserted in the final stages. The panels do provide some needed strength and stiffening, but since there is no wind resistance without the panels, I don't the empty frame presents much of a risk.

Only exception would be the door and roof vent poly panels, as those are inserted into the door frame and roof vent frames before those items are added to the greenhouse structure.

It's a good idea to double check squareness as you go, to be sure you aren't surprised with any openings that are slightly out of square (this doesn't present much of a problem until you start placing the panels!)

Best of luck with your build,

Anonymous said...

Thanks! I have just now come upon another challenge: My subdivision rules restrict me to no more than 8 ft high on a greenhouse. This one's a little more than 10 ft.

Do you think it is feasible to shorten the bottom portion of this kit in order to meet the restriction? Worth the effort?

mudhouse said...

I have not read about anyone modifying this kit to reduce the height, so don't have good advice. I think it would be difficult as the diagonal braces would also need to be shortened, in addition to the wall studs, and the sliding doors would also be too tall for a shortened structure. I don't know how you could modify the doors to work.

Another idea would be to consider building the greenhouse in a "pit" so you step down into it, but this idea is also beyond my level of experience, I'm afraid.

You might look at the Harbor Freight 6' x 8' greenhouse, as it is not quite 6 1/2' tall at the peak, according to the HF website. Smaller greenhouses can be harder to keep cool in warm weather, but that might be a better option than trying to modify the 10 x 12 to a shorter height.

Of course, anything is possible with enough time and determination, but I think it would take a lot of re-engineering (off the top of my head.)

Unknown said...

Hello Mudhouse. My name is Jon. I live here in the Bay Area in California and received my new HF Greenhouse as a birthday present this weekend. I took one gander at the instruction booklet, and like they said in the movie Beetlejuice, "It reads like stereo instructions." But thankfully I Googled info on the greenhouse and came upon your blog. Thank the lord for wonderful people like you who take the time to make putting a project of this magnitude seem not so overwhelming. I literally just opened the box, only to find several more boxes. Do you have any sage wisdom for a newbie at this stage of the game? I am curious whether you think it would be wise to purchase nuts and bolts of a stronger steel rather than using the aluminized type screws and bolts that come with the greenhouse? I will most certainly be contacting you in the very near future with questions and gripes and moans along the way. But, again, I want to thank you for your patience, insight, and dedication in putting this information together for all those of us who so desperately need interpretation from the "Place tab A into slot B" type instructions. I am so looking forward to having a completed greenhouse. I can only dream of the hours and hours I will spend putting around inside my magical, see through creation. What wonder awaits!

mudhouse said...

Hello Jon,
We used the bolts that came with the kit, and they've held up fine for years. I do think they're steel, with some kind of plating that gives them a cheap appearance that some folks find alarming.

As I describe above, it can be tricky to find bolts with the same sized/shaped head as those that come with the kit, which is why some folks have sought out help at Fastenal. The size and shape of the head needs to work in the tracks of the studs. The prices I have listed on the blog page above for Fastenal bolts are now several years out of date, so you may want to research current pricing too, as I'm sure prices are higher now.

Some folks in online forums have mentioned they felt better buying more expensive bolts, but based our our experience (and based on the difficulty and cost of finding replacement bolts that will work as well, size and shape-wise) we wouldn't worry a bit about using the bolts that come with the kit.

Good luck with your coming greenhouse!

mudhouse said...

Also, my advice for someone who has just received their kit is to 1) take the time to make sure all the pieces were shipped to you (check them off against the list in the manual.) It's tedious, but if the folks in China forgot to include a part of the framing, it's better to find it now, than when the structure is halfway completed and you're up on a ladder. It's not common, but some folks do receive incomplete kits, and Harbor Freight is very slow (many months) to ship missing parts that they don't consider "stock items."

2) I strongly recommend using additional clips to hold the panels in place (as well as screws, as you'll read in my section on installing the panels.) I'd order the extra clips now from the toll free Harbor Freight number on the manual, so you have those ready when you need them. Usually they seem to ship these pretty quickly, but this way you won't have to worry.

I hate worrying. ;-)


I'm having a bit to trouble trying to get the clips to hold the panels. The instruction illustration is usless. I know anyone should be able to snap it in place but I want to get it exactly right the first time. Thanks.

mudhouse said...

Hi American Sky,
The clips can be confusing at first. (Easy to show you, but hard to explain in words!) I have one photo in this blog of an installed clip, and that is in part Seven, Greenhouse Enhancements. Scroll down to the section on "Aluminet Shade Cloth Screen Panels". The fifth photo in section part shows a close up of an installed clip (although it's holding a white metal screen panel in place, and not a clear polycarbonate panel.)

So, you’re standing outside the greenhouse, since the poly panels sit on the outside of your greenhouse frame. The two ends of the clip (let's call them "feet") will be captured inside the curve of the aluminum track. The center part of the clip presses down on top of the poly panel, while the two clip feet are caught in the aluminum track, to keep the clip center pressed down on the panel. The two small v-shaped bends in between the feet and the center (let's call them "shoulders") slip a bit behind the panel edge.

Unfortunately, my clip close up photo in Part Seven doesn't illustrate this very well, since my Aluminet screen frame (the glossy white part in that photo) is a bit too fat to allow the clip "shoulders" to slip behind. But, these small curves really do go behind the edge of the thinner poly panels, and that is what Harbor Freight is trying to show you in the (unclear) illustration C on page 16 of the Harbor Freight manual.

One trick I've learned is to put the clip in place this way...hold the clip so the center curve will come in contact with the panel. The two "feet" are sticking up, in the air. Capture the bottom "foot" in the track, and allow the center curved part of the clip to press down on top of the panel. Then, click the top "foot" into the track. I find this easiest, but others may have their own way.

To remove a clip (and I do that often) I use a screwdriver to gently pop the top "foot" out of the track. The clip then falls right out, once I free the top "foot."

One other thing...when learning, try using on one of the wall studs that is not a corner post. The clips fit a bit tighter in the tracks in the corner posts...because the flange that catches the "feet" is a bit smaller on the corner posts, so they require a bit more effort to click into place. Try learning on one of the other wall panels.

All of the above sounds a lot more complicated than it really is. If it's still confusing, please feel free to send me an email at, and I can email you some better photos of installed clips on my greenhouse.

dwest said...

I was just lucky enough to buy a used 10x12 HFGH in good shape for 200 bucks and was wondering if anyone could advise me on the best was to tear it down w/o totally dismantling it. I will be transporting it in the bed of an s10 but was hoping i could get away with taking the roof totally apart and off the GH and dissconnecting each wall from each other and laying them down in the back, It looks like each wall comes apart in half so it should fit laying on its side.I have seen a lot of how tos online about assembly but not much regarding disassembly or best way to transport or move and I've never built one before so taking it apart the best way to transport isnt exactly clear. I would imagine having built one before makes tear down a little easier (hopefully).Any and all advice is appreciated because right now im thinking that i have to basically tear the whole thing down and rebuild at my house . Any tips about this endevour is greatly apprecaited once again. Thx

Unknown said...

Unfortunately the structure of this greenhouse is fairly flimsy even when fully assemble. I and others have done significant alterations to make the assemble greenhouse more stable.
Your best bet is really to fully disassemble the main structure, only the sliding doors and the tilt up roof panels can be kept intact, they are a sub-assembly anyway.
You can download the assembly instruction from Harbor Freight to put it back together but read some of the old post for advice on additional structural enhancements for when you rebuild it.

dwest said...

thx for the advice. I think I will go with the route you stated with basically full tear down but leaving sub assemblies intact(sliding door and tilt up roof panels. my plan is to use a sharpie to mark a line above and below on the main structure where the smaller pieces are and then removing the piece, marking a number on the removed piece and inside of the lines on the main structure. a lot of the old number stickers are worn off so using the manual (which the prior owner gave me) will only get me so far but it should still help quite a bit overall. Doing it this way should enable me to know where the pieces go and which way they are oriented.(hopefully) I will also be taking plenty of pics before and during the tear down process to use as a reference. let me know if u see any flaws in my potential method. thx again

mudhouse said...

Dwest, we haven't disassembled one yet. I'm thinking the previous poster is right, it's probably best to dismantle the walls and roof, but you could remove all the panels, and then feel your way through the process. And Unknown is also correct, no need to dismantle the doors and roof vents.

A few thoughts:
The aluminum in these kits is pretty soft (easy to bend.) For example, the aluminum stock sold at the box stores is harder than the kit material. I think moving large pieces may increase your chances of accidentally bending some of the components.

I'd remove the polycarbonate panels to protect them. Since the greenhouse is used, it may have been exposed to enough sun (depending on age and shadecloth use) for the panels to have lost some of their original flexibility. Over time, my panels have become more yellowed/brittle, so they are more fragile to handle.

If the previous owners have not caulked the panels in place (I have not, but some folks do) the clips should be easy to pop out of the tracks.

If the previous owner has screwed the panels into the aluminum frame (which I highly recommend) I’d number each panel with a Sharpie pen, so you put them back in the same position. This will save you re-drilling new holes to reattach the panel screws, and no musical chairs to see what panel goes where. I unscrew and screw my own panels all the time, using the same screw hole in the framework, no problem.

Harbor Freight parts come with little paper round part number labels. If these are still viewable, that will help. If not, you could number the aluminum parts with a Sharpie marker, to make some kind of reference (roof, door, back wall brace, etc.) If you are methodical, you could number them by using the part numbers shown in the Harbor Freight manual. (That would be my approach, but I’m a hopeless detail wacko.) Lacquer thinner would remove any marks on the aluminum later.

Harbor Freight keeps revising the manual. A kind HFGH owner alerted me today that the newest manual, shipping with brand new kits, differs from the downloadable PDF manual on the website. (Apparently, Harbor Freight hasn't updated their website yet.) The new kits have some new parts. However, I'm guessing the current PDF manual on the website will serve, since your greenhouse is used, and any changes are hopefully pretty minimal.

As the previous poster stated, be sure to make some of the inexpensive enhancements mentioned in this blog, to improve the strength of the structure.

Keep up with the bolts. They are perhaps a tad soft (not the greatest quality) but the heads are specially shaped to slide in a grove in the wall and roof studs. It’s a little hard to find regular bolts that will fit in the channel as well as these, if you lose or damage them. You can probably order them from Harbor Freight, but I don’t know how quickly they'd ship these (some items seem to ship faster than others.)

And, photos before or during the dis-assembly process are a great idea.

Congrats on the good price!

dwest said...

thx again you guys and gals are awsome !! Now the only dilemma is keeping track of what bolts go where. when I take the piece/part off of the main structure do most of them have holes on them to temporarily stick the bolt through it with the nut on the backside to keep it in place? I'm just trying to figure out how not to lose track of where they go.

mudhouse said...

dwest, I don't think that would be a bad idea at all (to put a bolt and nut back in the hole, after you take a piece off.)

When you're putting it back together, the varying bolt lengths will make more intuitive sense, too; longer bolts are used where the bolt has to hold multiple parts together.

With your good attention to detail, I'm not a bit worried about your ability to handle this project well. :-)

Unknown said...

How the heck do you put parts 12 and 13 together? The instructions say to "Insert a Plain Side Ceiling Plate (13) in the brackets on the end of a Side Ceiling Plate with Brackets (12)." I see no brackets on part 12! Both ends on 12 and 13 come to a blunt end with all projecting parts so it is impossible to overlap them. I did find some mystery parts (82), metal plates that could go across the join and fit the holes in 12 and 13 perfectly. They aren't listed in the parts list. Is this what they are for?

Unknown said...

BTW for those who asked about building a greenhouse with wood and glass: I built a fine, sturdy greenhouse out of recycled lumber and old 8' x 5' school windows, which I bought from a company that replaces windows. Because I didn't make the roof steep enough, water froze and broke some of the windows. (My husband thought that building a HFGH would be easier than fixing the old GH. He was dead wrong.) The point is that if you know anything at all about building, you can build a greenhouse; and if you don't it's easy to learn! I built my first greenhouse, about 8 x 10, for maybe $200; and the second one, 10' x 16', for under 500, including recycled pavers on the floor, a set-tub, and benches. Almost everything was recycled. I encourage you to consider this option because you will get a cheaper and much sturdier greenhouse!

mudhouse said...

Hi Diana, I don't blame you for being frustrated. I'm trying to figure this out, too, and I can at least give you a clue. Maybe we can figure this out together.

There are now two versions of the Harbor Freight 10x12 greenhouse being sold; the older, original version, like mine, is Item 93358. The newer version, with a few changed parts, is Item 69893. I am getting questions from folks on both greenhouses, so I know both are still out there on store shelves.

When I compare the parts lists in the two manuals for these two different versions, the parts you mention (12,13,82) have changed between the two kits. The newer kit has part 82, which is listed as a Floor Plate Bracket. The older kit has no part 82.

Look on the front of your manual; it will have one of these two item numbers. The manual that came with your greenhouse should match the version of your kit, of course. But then again, this is Harbor Freight, so we can't assume anything. (Insert bad words here.)

To help figure this out, you should probably go to the Harbor Freight website, and download the manual for the "other" kit. (If your manual says Item 93358, download the manual for Item 69893.) Then you will have a copy of both manuals in front of you, and you will be able to see the differences in the parts list, to try to figure out what's going on here.

This page on the Harbor Freight website shows the greenhouse kits available. Click on the link and download the manual you don't have:
Harbor Freight greenhouses

Maybe this extra information will help. If not, you are welcome to email me directly at, and we'll try to put our heads together to figure out what's happened here.

Unknown said...

Yup, the manual for 69893 had the info I needed. Thank you for pointing this out. Maybe I can actually get this thing together now.

mudhouse said...

I hope so. If Harbor Freight starts mixing up parts between the older and newer kits, and mixing up manuals, we may all have to start drinking heavily.

Sorry to hear about the loss of your previous greenhouse, it sounded great. If it's any consolation, you'll find the twinwall polycarbonate in your HF kit (even though it's a fairly low quality 4mm twinwall poly) will hold in heat better than glass. It should cost you less to heat during the winter, if you do so. If I built my own greenhouse from scratch, I'd at least price out twinwall poly (purchased from a greenhouse supply, not Harbor Freight) before I'd use glass...depending on my climate and heating needs.

Although there's nothing quite as visually lovely as a nice glass greenhouse. :-)

Let me know if you need any other help,

CK said...

Hi Mudhouse,

I am fixing to start assembly on the 10 x 12 HFGH next month and I'm thankful I found your blog. Currently I am taking all your advice into consideration.

It concerned me to read in your blog update of October 2011 that your greenhouse panels were decaying prematurely and needing replacement.You reported that your panels started yellowing in only nine months and further decayed to the point of replacement after a little over four years. It is now two years later. Could you please give an update as to how you solved the problem?

Specifically, I would like to know:

Did Harbor Freight replace the panels?
Where did you find replacement panels and cost?
How are the new panels are aging with respect to the original HF panels?

I would like to thank you for your continued support of this blog. I know you have helped me and many others. Thanks!

mudhouse said...

Hello Cashley,
If Harbor Freight ever replaces panels because of deterioration problems, I'm not aware of it, and they certainly did not do it for me. They emailed me: "Our warranty for the parts for this product is only 90 days." Their current manual cites the same 90 day warranty.

This is awfully disappointing, but I've come to consider it a trade-off for the (in my opinion) very low cost of the Harbor Freight kit. I posted the panel problem info at the front of my blog so folks would be able to take this into account, as they consider their purchase.

My roof panels deteriorated the most quickly, even though they were under 60% Aluminet shadecloth year round. We replaced those in October 2011.

At the time, I priced 4mm twinwall polycarbonate at a number of greenhouse supply companies. The best price at the time was through FarmTek. Their product had a ten year warranty, and was truly UV-protected. However, the cost to purchase enough material (just for the roof) with crating and shipping fees, was $410. The cost to order more Harbor Freight roof panels, with shipping, was $135. Also, the HF panels arrive sized to fit; if you buy better polycarbonate from a greenhouse supply company, you'll have to cut the material to size yourself for each part. Not difficult, but it does take time.

I cheaped out, and reordered from Harbor Freight. Of course, I'll have to replace them again, eventually. So far, two years out, they don't show signs of deterioration, when I pull up my shadecloth to check. If I did not have the roof entirely covered by shadecloth year round, I'm pretty sure I'd be seeing deterioration sooner, in my sunny climate.

I also tried a product on the new Harbor Freight roof panels this time. I honestly don't know if this is helping, or not; I can't state definitively yet. I'll know in another few years. I ordered a clear protective coating from an internet company named Top Secret, and applied it with a low-nap roller to the outside of my new roof panels. It cost me a bit over $100 to order a gallon of the product, and the required thinner to use with it. The name of the product I'm testing from Top Secret is their TS-100 Clear Silicone Epoxy, thinned with their TS-101 Thinner. It does not seem to affect the light transmission of the panels, and dried quite clear, with only a barely discernible yellow cast. It could be this product is helping delay problems with the new HF panels. Or, it could also be, the panels simply have not yet reached the point of beginning to show problems again. My first set of Harbor Freight roof panels lasted four years, and this set is two years out, so time will tell.

At this point, all of my original six year old Harbor Freight wall panels (except those on the sheltered north side) are in bad need of replacement. They're still functioning fine, but look ugly. They're quite yellow, cloudy, a little brittle, and have some scattered 1/8" holes in the outside layer of the twinwall poly. I have carefully patched each tiny hole with a small square of clear duct tape, to preserve the air tightness of each channel.

I really meant to replace the wall panels this year, but procrastination and a few health problems distracted me from that goal. Come spring I will most likely replace them with more Harbor Freight panels, since that is by far the cheapest option, and I managed to get six years out of the walls (six and a half, by spring 2014.)

Sorry this is not more encouraging, and I hope it helps!

Unknown said...

One of the bad items in this Green House Kit is the Nuts.They Rust up in humid climate real fast.In a few months they are all rusted up.

I will have to replace them with a Aluminum Alloy or Stainless Steel Nuts.

mudhouse said...

Sorry to hear that, SilverDollarSaloon. We haven't had any problems in our very dry climate, but your comment is a good heads up for those in humid climates.

Karen Sothoron said...

Karen S. asks: I just bought a 10x12 Harbor Freight greenhouse. Can anyone tell me what the snow and wind load tolerances are for the kit? And what are they for the Mudhouse modified kit?

Karen Sothoron said...

Can anyone tell me what the part number is for the glazing clips? I've tried all combinations of wording in the Harbor Freight 'search' and nothing comes up.

mudhouse said...

Hello Karen,
Harbor Freight does not sell the clips on their website, or in their stores (no idea why.) You have to call the 1-800 number on your Harbor Freight manual to order clips.

The clips are identical for both the 6x8 greenhouse and the 10x12 greenhouse. But if you want a bag of 72, you can order the clips (supposedly) for the 6x8 greenhouse. If you want a bag of 130, you can order the clips (supposedly) for the 10x12. They are the same clips.

Giving them the SKU number when you call will save you the time of waiting for them to look it up, and sometimes avoids confusion, so those are listed below.

For the 6x8 greenhouse:
Part number 46 panel clip
SKU number 27339, set of 72 clips, $9.99

For the 10x12 greenhouse:
Part number 53 panel clip
SKU number 29457, set of 130 clips, $15.99

These numbers and prices were accurate when I ordered last year in 2013. They will add a small fee for shipping. In my experience these have always shipped pretty quickly.

Unknown said...

I found the instructions to be quite good. Many of the problems mentioned seem to have been addressed. The diagrams are also good

Ethicsfall09Locke said...

I built a HFGH 10x12 a couple years ago and have been working on combatting the high temps in the summer and cold in the winter. Recently I have found a way to add a 6mil greenhouse poly film. The film I get for free from area temporary greenhouses that businesses put in their parking lots. Last year I used Velcro to attach the film on the inside, but eventually the sticky backs of the Velcro let loose and the poly film fell. After a lot of standing and starring, I noticed that the frame work of the HFGH is made with a perfect solution in its design. I installed the poly film on the outside with clips that I made with 3/8 id poly tubing that is designed for ice makers. The poly clips snap on the 3/8 rounded part of the aluminum frame work. This gives me a comparable insulating value as a poly air inflation system.

shadytrake said...

Nice blog! Just as an update, you can get replacement or extra bolts from Harbor Freight now. They have two misc assortment nut, washer, & bolt kits. Item no. 67624 & 67532. These are usually in stock. Several of the bolts fit the channel and they come with the matching nuts. The kits are cheap at about $4.

mudhouse said...

Thanks shadytrake, that's good to know! Your update is much appreciated.

Unknown said...

I having a problem with my doors.. the right door is hard to close or open... left side is great. I don't see any thing out of place but notice at the top where roller attaches on right side there is a gap about halfway down the door brace. I have to put up on that side of my door for it to close and then some of my pins popped out holding my door panels .. have you ever heard of this happening

mudhouse said...

Hello Natalie; I'm not familiar with this problem. If you'd like to email me at, perhaps we could email some photos, and do more detailed troubleshooting to try to figure out the problem.

Unknown said...

Hi Sheri,
How much room at the minimum do you think is needed between the GH and another structure, in order to allow for ease of installing the panels and future maintenance?
Thank you!

mudhouse said...

Hello Darren,
Sorry for the slow reply, I've been out of town. We have a bit over four feet between our house and the greenhouse, but that was partly because our house has a deep roof overhang, and we didn't want the house roof to contact the greenhouse roof. It has been a handy size space for me; enough room to walk easily between the two structures, and I also use part of it for storing stacked pots.

Unknown said...

Thank you Sheri for your response. No worry about the late response. The foundation is finished, and I am ready to start on the adventure! Unfortunately, my GH from the local store is the older version (like yours), Item Number 93358. I noticed that a poster above me asked about some parts that are present in the new GH kit, but absent from my kit. I looked over the parts lists from both, and found that the new GH (Item Number 69893) have these additional items: Part Number 82 Floor Plate Bracket (quantity 4), Part Number 83 Straight Bracket (quantity 7), and Part Number 84 Crown Bracket (quantity 1). My questions are: do I NEED these new parts? Did you retrofit your GH with these additional parts?
Many thanks for your help!!!

mudhouse said...

Hi Darren, no, if you have the older version of the kit, you don't need the parts from the newer version of the kit. A few parts of the greenhouse have been redesigned (for reasons unknown to me) and some of the parts are a bit different now, that's all.

Your kit, and the parts pertaining to it, will be all you need. Just make sure that the parts listed on the back pages of your manual are actually present in your box (sometimes HF ships kits that are missing a part, and that's not a happy discovery.)

I really don't see any problem with the older version of the kit; mine has served me well for about 8 years now.

The areas I do have some gripes with (the polycarbonate panels need more UV resistance, and my roof window vents would not stay down snug in the wind) haven't been changed in the new version either.

Unknown said...

Great to know that I don't need the new parts. What type of screws (size & material) did you use to secure the steel base to the timber? The base is in a C shape, did you have any problem keeping the drill straight to make the holes, or did you go in at an angle?
Thank you,

mudhouse said...

We used large screws, the type designed to secure metal roofing to a wooden frame, the largest size we could find. They have a metal and rubber washer right under the head. (You can google "screws to attach metal roofing to wood" and you'll find pictures.)

I understand what you're asking about the C-shape of the metal base restricting easy access for drilling. We really didn't worry if the screws went in at a slight angle, best as we can recall.

Honestly, it's been too many years to remember if we did this, but you could drill holes in the metal C shape, from the bottom, before flipping it over to screw it into the wooden foundation.

If you drill holes in metal, it's always easier to start with a small bit (good quality, as the cheap ones will break) and then move up to a larger bit to drill a larger hole to accommodate the screws you use. Hope this helps.

Unknown said...

After nine months of procrastination it is time to erect. the four corner connectors are 1/4 inch longer than the base plates are high so will not fit on the inside. Choice seem to be request replacement parts (but I am on a role so do not want to wait), trim the parts to proper length, or attach to outside of corners - I went with the latter, seems to make sense but not certain.

Other issue is squaring the base, the included instuctions say corner to corner should be 15' 5", but the hypotenuse of a 10'x15' triangle is around 15' 7". Your blog says simply to make certain the corner to corner lengths are the same, so I am moving forward with fingers crossed - BTW, one of the sides measures 12' 1" , should I be concerned? THANKS, Dave

mudhouse said...

Hello Dave. We let our kit "age" in the box for a while, too. ;-)

Hmmm. So, when the base is assembled, using the corner connectors and the end connectors, do you mean that one side of the base measures 12' 1", and the other side of the base measures 12'? If so that would concern me, a bit. My husband wonders, could you split the difference (meaning, very slightly adjust the base, so the corner to corner measurements are as close to the same as possible?)

I've not heard of this kind of manufacturing variance before, with any of the HFGH parts (if that's what is happening here.) I've never had anyone have to modify parts, either, to get the fit right.

Do you mind me asking, what is the model number, on the front of your manual? I'm wondering if this might be a new kerfuffle with the newer version of the 10x12. We surely did not have these discrepancies with our kit, so I am scratching my head. I'm sorry to not be of more help; this is a new one for us.

Please feel free to post back, or email us directly at, if you'd like.

Unknown said...

Hi Thanks VERY much for the quick response - I am not so reliable. But now back to work (so much for being on a roll :-)

I was mistaken about the measurements - this time I asked my wife to help meaure, the accurate dimensions (triple checked) are 9' 7/8' x 12' 3/4". Not quite the 10x12 but at least it is square.

My instruction manual gives the item # as 69893. On page 7 it states the diagnonal to be 15' 5" . They may have gotten confused in translation (if this is not U.S. made) and converted 0.5 into 5"- even though it should be 0.6, close enough I suppose.

However, my dimensions in decimal are 9.875' x 12.75' giving a hypotenuse of 16' instead of 15.5 - will let you now how it works out.

Thanks again

BTW - I have worked 30 years as a technical writer so might be a tad more picky than most when following instructions.

mudhouse said...

Hi Dave,

So, you have the newer version of the kit, and I can see the accompanying manual does state the diagonal measurement to be 15'5".

Interestingly, I checked the older manual for our older version of the kit, and it states the diagonal should be 15'10", not the 15'5" shown in the new manual. As far as I know, the footprint size of the kit has not changed, so I am at a loss to explain the discrepancy between the two manuals/kit versions. The 15'10" measurement is much closer to your 16' diagonal measurement. Maybe, there is a typo in there, somewhere?

It's at this point I throw up my hands, and say, let's just make darned sure things are plumb and square as we go, and I think everything will work out fine. This technique is called, Avoiding Unnecessary Math, but that may be a personal quirk of mine. Heaven knows these manuals have been know to include errors, and a plethora of unclear statements. So I guess I tend to not worry too much when I find something that doesn't seem right, in the manual, if the real structure in front of my own eyeballs is looking right.

However, with your background as a professional technical writer, you may enjoy tracking down the mathematical truth of the situation; in that case, go for it! (I think Harbor Freight needs you.)

Hope all continues to go well for you.

Unknown said...


I just want to say a big Thank you for taking the time to put this blog together. My wife and I are in the final stages of building the 10x12 HFGH and we've gone to your blog many, many times during the construction process during those times when we found ourselves second guessing the construction manual (I'm sure that's a I have to say, the HFGH manual was one of the most horrible examples we've come across in our many DIY exploits. So, despite that, we are finally able to see the light at the end of the tunnel now, so we should be on track for some winter veggies, here in Texas.

Construction-wise we did a few modifications to the existing plan, some per your suggestions and others based on our requirements. We secured our base using a total of 8, 2' treated 4x4's sunk into ground (1 at each corner, 1 in the center of each beam) with concrete and then attached the C-beam to 4x4's after cutting a notch in the "C" beams (using our handy little Ryobi angle grinder) so the C-beam would fit over the sunken posts. This seems to give us a fairly solid base that was fairly easy to level and square. A side effect of this is that it gives the wimpy C-beams a good structural reinforcement.

And no thanks to HF, all of the longer T-bolts they provided, had heads that were too large to fit into the channel for the wall/ceiling braces. This was a nice little setback we weren't planning on and one we wouldn't have even thought about because the bolts all looked okay when we were inventorying the parts list...So instead of waiting the 6-8 weeks to get new ones, we simply ground the heads down slightly using the fore-mentioned angle grinder and carried on with construction. Nice....oh well.

Anyway, thanks again for taking the time to document your experiences with. It has definitely helped me as it no doubt has helped countless others wading their way through this nice little project.

Best Regards,

mudhouse said...

Hello Dan, and thanks for your nice comments. Sounds like your approach to the foundation is an excellent way to make sure it's secure, level, and square. I'm always appreciative when folks post details about the modifications they made; it helps everyone who reads here.

Recently, I've had a few other folks mention the new problem of the bolt heads being too large to fit in the channels. Thanks for confirming that. It's baffling that Harbor Freight fails to check the fit of these critical bolt heads before including them in kits, good grief! (Hello, Harbor Freight? Anyone listening?) And in my experience, if Harbor Freight tells you something will ship in 6-8 weeks, it might. Or, it might not, regardless of what they say on the phone. Your solution of grinding some material off the heads is what we would have done too. It's crazy you had to do that.

Your post also confirms a Universal Truth we've always lived by: You Can Never Have Too Many Tools.

Best of luck with your greenhouse, I hope you and your wife enjoy it for many years to come.

Unknown said...

Hi Sheri / mudhouse -

I also posted this in gardenweb forum that you list at the top of this page, but was not sure if you still monitor or get info from it -

We are prepping (laying down 4x6's for foundation atm) to install a 10x12 HFGH, around 2200' in Sierra foothills of California (Nevada City).

In applying the TS-100, did you prep your new roof panels by sanding them

to roughen the panel surface a bit for better adhesion? or just peel off the

film, thin the TS-100 and roll on? Can't use their primer, since it is colored.

Thank-you for your ongoing support and huge contributions to this site for all of us HFGH builders!!

mudhouse said...

Hi Jim,
No, I didn't abrade the surface of the new panels at all, and I didn't have any problems with the TS-100 product adhering directly to the surface of the panels. No peeling, no flaking, no yellowing from the application (well, perhaps a very barely noticeable tint, afterward, but nothing that worried me.)

As you said, I removed the protective film, thinned the product with their proprietary thinner, and rolled on two coats. (I think one poster on Gardenweb applied three separate coats.) Personally I wouldn't do anything to rough up the Harbor Freight panels, since (for me) they have already proven to be pretty questionable in their durability, over time. I'd be kind to them!

I do think the TS-100 product helped us a bit, but I'm sorry to report that I still only got a bit more than three years out of my second set of Harbor Freight roof panels, even with shadecloth on top year our tough desert climate. I could tell they were getting brittle, and a recent hail storm with 1" hail punctured them nicely (although the greenhouse frame was just fine.) So we've just covered the damaged greenhouse roof with 6ml UV greenhouse plastic, to get us through the winter. In the spring I'll be ordering new 4mm twinwall polycarbonate, probably from Farmtek, to put a new roof on the greenhouse. Their polycarbonate has a 10 year warranty...and UV protection. I'm getting too old to keep re-roofing the greenhouse every three years, lol.

I do think people in kinder climates with less intense sun fare better with these HF panels, and I still think the TS-100 probably helps extend the lifespan, somewhat. If I was ordering new HF panels, I'd use the TS-100 again.

mudhouse said...

Correction...I double checked my dates, and we got about four years out of the second set of Harbor Freight roof in sunny southern NM, after applying two coats of the TS-100.

My wall panels are all still original, so about 8 1/2 years old. They now need replacing too, because they're very yellowed, brittle, and have a few small holes in the outer layer, but they haven't deteriorated to the degree that the roof panels did.

It seems to be all about how much direct sun exposure they have. The wall panels on the north side, covered on the interior by foam insulation, and sheltered on the outside by our house, still look like new.

Unknown said...

Mudhouse you saved my sanity
I just finished construction of my 10 x 12 HF greenhouse. Quite the experience.When my greenhouse arrived it did not have a manual. I got the manual online but without your blog I would have put the greenhouse up much like described in the manual. That would be a major mistake. Your blog is superb!!! I am sure you saved me from a disaster. We don't get too much wind here in western Oregon but when we get wind it can be strong. I remember in 1996 my wife and I were watching Twister on the TV when she said the wind sure was strong tonight. I told here it was just the movie, since we have surround sound. She said, then what happened to the full size wood picnic table in the back yard. It had blown over the fence into the pasture by the yard. A few years later I had a 12 x 12 canopy up in the yard and a wind came up and blew it apart and bent the 5/8 rebar, anchoring the legs, to a 90 degree angle. So I took your reinforcement comments to heart. Your illustrations and advice are excellent. I followed your instructions closely. I made a few modifications as well. On the base I did screw the steel base to the foundation as you suggested but I still felt it was a pretty vulnerable part of the total construction. So I bolted the 1 x 6 cedar boards to the steel base by drilling through the steel base and the stiffening board and tied them together with 1/4" stainless steel bolts (about 2 1/2" bolts as I remember) using 5 on each long side and 4 on the short sides. I then tied the bolt to the 4 x 6 foundation with a 6" steel mending strap. I did this in six places. this is now very stable.
I also used 4 3/4" emt bars to strengthen the sides. I used a 10' hemlock across the doors since I liked your idea of adding a screen door in summer. Part 52 has changed since you built your greenhouse. It is now a 1 1/4" wide steel bar the width of the panel, which slides into the bar. With one of these in each panel the back is pretty stable. With all of this done I feel pretty good that it will withstand the rare but severe wind we get here. Thank you so much for the ideas since without you I wouldn't have given this enough thought.
A couple of other thoughts. I ordered the extra panel glazing clips as you recommended. I feel now, they are absolutely necessary to hold the panels in place.
When I went to Home Depot to buy neoprene washers to space the panel from the interior braces they told me they don't stock them in bulk. They only had 12 in the store. So, I bought a length of 3/8" clear pvc tubing and cut it to about 3/8" lengths. Then used these pieces of pvc tubing instead of washers. They are almost invisible. That worked great and cost almost nothing.
I did find that there are some changes in the basic plans for the greenhouse that are all probably improvements. The change in part 52 is excellent. The front base is now totally different and the doors work very smooth. The doors hang on the wheels at the top and float in a groove in the bases.
One frustration was that a bunch of parts in my manual were not in the kit and I had a few parts that were not listed in the parts list. Actually the parts in the kit were all correct and the the "missing" parts were not needed. This is one place where your blog and all the excellent pictures kept me on the right track and I got the greenhouse up correctly. With no parts left over! Without your blog I would still be trying to figure out how all this stuff fits together.
Thank you so much for taking the effort to help so many of us!!!
I've now got the water and electricity in and as soon as my wife decides on how she wants the benches I'll finish it all up.
Bill in the Valley

mudhouse said...

That's impressive wind you have there Bill, I'm really glad you found info about reinforcements. I doubt our greenhouse would have survived long either, if I hadn't read many Harbor Freight greenhouse tips in the Gardenweb greenhouse forum. They saved my sanity, too.

Sounds like your base modifications will serve you well. And I'm glad that Harbor Freight has made some improvements, over the years. I can see the new design for the Part 52 panel connector in the new manual, and it does look like a vast improvement!

Glad you ordered extra clips. The longer I have my greenhouse the more I value using extra clips. Not only do they make the panels less likely to be blown out; in my GH, they also help the panel make better contact against the weatherstripping I used around each opening. The more clips, the better the contact, the less air leakage in winter around each panel.

Great idea about making your own washers out of clear pvc tubing. The little neoprene washers can be kind of pricey, too. The ability to do a little on-the-fly creative engineering is a big help, with this kit.

I'm also happy that Harbor Freight has redesigned and improved the doors. Mine still work, but they can be fussy, after 8 years. Other owners of the newer HFGH have also written that the doors seem better now. Hooray. The old ones have been a point of frustration, for some owners.

I do hear comments about the parts in the manual not quite matching the parts in the kits. I know there are now two versions of the 10x12 greenhouse out there; the one I have (item 93358, still available in some places) and the newer version (item 69893.) And there are now two 10x12 manuals as well, downloadable on the Harbor Freight website. Sometimes when people write me about parts discrepancies, we finally figure out that the manual they're using doesn't match the kit they have. The item number is listed on the front of the manual. I'm not sure if this might explain your parts discrepancies, but I'm very happy you survived the process, in spite of the confusion!

I often say it's a good thing most gardeners are a little bit stubborn, by nature. I really appreciate your nice words, and I wish you and your wife many happy years using your greenhouse.
Sheri in the Desert

Unknown said...

Where I would place the greenhouse is right up against a chain link fence. Can I install the panels from the inside? Or can I assemble that side - including the panels - before I set it up?

mudhouse said...

No, the panels can't be installed from the inside. Each panel sits inside a channel on the outside of the greenhouse, held in place by clips (and screws, if you've read my blog.)

We built our greenhouse in place on top of the foundation, but I have read about people who assembled the frame, and then (with multiple helpers) lifted the frame and set it down on top of the pre-built foundation, and then secured it. It's really not that heavy, without the panels, and it can be done with help. So, theoretically you could assemble the frame, and install only the panels on the one side wall, then sit it into place on the foundation, and secure it.

I worry a bit when people build the frame, install all the panels, and then move the whole greenhouse into place. That can be done too, but I know of occasions when a breeze sprang up, and tumbled the whole greenhouse across the yard. (It's like a giant box kite, when not anchored securely to the ground, so fair warning.)

I think it would be a little tricky to install the roof panels on the fence side without access, but I think it could be done, working inside the greenhouse, on a ladder; start with the center roof panels, and work out towards each end.

To be honest I really don't recommend building it right up against a fence, though, if there's any way you can possibly avoid it. Here are some things to consider:

You might need to repair or replace panels, down the road, and then you'd be in a pickle. The Harbor Freight polycarbonate panels don't have enough UV protection to last as long as true UV protected polycarbonate from greenhouse supply companies. I've replaced my Harbor Freight roof panels once already, and will replace them again in the spring, along with most of the wall panels, because of deterioration from sun exposure.

Also, you'll probably need to use some kind of shadecloth on the roof (most of us do) and you'll probably (?) need access to both sides of the greenhouse to secure it. If the fence side of your greenhouse gets much sun, you might need shadecloth on that wall too, for part of the year, depending on your climate and orientation.

The closer your greenhouse is to a neighbor's property line, the more easily it could be damaged by accident; one person I know had his polycarbonate panels accidentally sprayed with paint because of a careless neighbor.

You might also check to be sure that erecting a structure right on the property line won't make problems with local codes...but you've probably already run that down.

I know some situations don't give you many options, but if you can give yourself a minimum of two feet of space to between the greenhouse and the fence...I sure would. It wouldn't be comfortable, but I think that might be enough space to service the side, if you can manage to give yourself that much room. Hope this helps.

Unknown said...

The coating on the screws is probably galvanized. They used galvanized coating to avoid causing corrosion on the aluminum. Steel and aluminum do not mix.

Unknown said...

I've had the GH up since Oct 2014, THANK YOU for the blog, helped tremendously. Anyways, about a couple months ago, our much despised HOA saw the GH, and have issued a letter demanding that the height be lowered to 7 feet at the highest point. So now I will have to remove the roof,and instead of having the new "roof" be sloped, I'll just have to figure out a way to have a flat roof, all walls will be 7 feet tall. Is there any idea you guys can think of for a new roof?

BTW, initially the HOA wanted to GH taken down entirely. After MUCH wrangling back and forth, they have agreed to let me have it, but lowered to 7 feet.


Unknown said...

I've had the GH in place since Oct 2014, much thanks to everyone and OP for this blog, helped tremendously! Anyways, our much despised HOA caught a glimpse of it a couple months ago, and have issued a demand to have it lowered to 7'. That's the height for any structure erected on our property that's not of a permanent nature (such as gazebo, patio,....). What are some ideas you guys can think of to have a horizontal roof placed instead of the current sloped roof?

mudhouse said...

Wow Darren, that's a shame. I don't have any good ideas off the top of my head about how to build the HFGH with a flat roof. I can't recall where you're located; do you have snowfall to deal with? Of course a major problem will be how you shed rain/ice/snow off a flat roof.

The walls of our HF greenhouse are 7'1" tall, because of how we built our foundation (steel foundation sitting up on top of a wooden base.) So facing the same restriction, I guess we'd have to just take our greenhouse down. How tall, exactly, are your walls? Do you have any room for even a slight slope?

Brainstorming (uselessly)...there are earth-sheltered greenhouses, or pit greenhouses, with part of the wall sunk into the ground. This would allow the final height of the part above the ground to be less. But the fragile HF structure really doesn't lend itself to this type of construction, even if you bought a new kit. Unless, you dug a large area, built retaining walls from block (or similar), built steps down, and put your HFGH structure in that area...maybe with room to walk around it. (Do you, by chance, have your own construction company, she asks hopefully?)

I think though you'd be better off to just build a greenhouse from scratch, in that situation.

I'm hoping others might read your post and offer better ideas than I have, currently. I really hope you don't have a large plant collection you need to winter through in the greenhouse. Getting this type of news, in November, would be a total disaster for me.

We'll keep thinking. Any one else have a few thoughts?

MagicBill said...

OK, so the HOA is going to mess with you. Time to mess with them.

So if the greenhouse is a free standing fixture, it has to be no higher than 7 feet.
But what is you extended the foundation on the rear of your house and then built the greenhouse as part of your house?

Then it is not free standing but an extension of your house. It is then a conservatory or sun-room, not a free standing greenhouse. Then you could enter the structure directly from your house. I'd still have a steel door or something solid to secure your home but still leave the other door for access outside.

That, or built it in a pit. I like the extension to the home myself. Would be easier to heat in the winter...

Either that or sell your home to a redneck who will keep junk cars in the front yard and not mow the grass and you can live in the country and have a chicken coop as well.

Good luck!

mudhouse said...

Magic Bill's suggestion also reminded me of another question. If 7' is the height restriction for a structure that is not permanent, what would it take to have them consider your greenhouse a permanent structure? Our HFGH is going on ten years old...

In our county, if we had poured a concrete foundation, our greenhouse would have been a taxable improvement to our property...because it would have been considered "permanent." But because we used concrete pavers sitting on the ground for the interior floor, they did not consider it to be permanent. So, no increase in our property taxes due to the greenhouse. (I'm sure this kind of thing varies greatly.)

Just wondering if adding a concrete floor would appease your HOA. That might be easier than tearing off and rebuilding a roof (on a structure that is clearly not designed for a flat roof...) What would it take to make it "permanent?"

Unknown said...

How do you find the part number for the roof panels?

mudhouse said...

Hi Anetta,
You can find all of the part numbers in the back of your manual. The roof panel is part number 60 for the 8x10 HF greenhouse.

If you're calling to order more roof panels from Harbor Freight, be sure to tell them which model 8x10 you have. There are two different kits, and according to my manuals (I have both) there could be a slight difference in roof panel sizes, between the two kits. Your manual will either say Model 93358, or Model 69893. But both manuals use the same part number for the roof panel; Part number 60.

For some GH parts, the model number makes a big difference; not for others. Always best to be very clear about your kit model number when you get Harbor Freight on the phone (sometimes you have to really repeat things with these folks.) Hope this helps.

mudhouse said...

Anetta, so sorry, what an error on my part! Trying to post fast, as I head out the door. I meant to type 10x12 greenhouse, not 8x10 (there is no such thing in Harbor Freight.) Sorry!

Unknown said...

I meant to ask if you knew the SKU #. Thank you for the reply.

mudhouse said...

No; I think the only way you can get the SKU numbers for HF parts is to call them and ask. They did provide me with SKU numbers, years ago, for the variously sized packages of panel clips, when I was trying to post information about which packages were available for order.

Why do you need to know the SKU# for the roof panels? (Just asking; I often learn helpful things by asking apparently nosy questions!)

Unknown said...

Just thought it might be easier to order with that number.

mudhouse said...

Okay, thanks! I've ordered replacement roof panels for my greenhouse, and the part number (along with your greenhouse model number) should get you what you need. They do have SKU numbers for parts, but they seem to be mostly used for HF reference inside the company. I hope they can send you what you need, and best of luck to you!

MC said...

It's been several years since this post but I just had to say: Thank you!! We have just built ours and found your documentation incredibly helpful.

mudhouse said...

Thanks for posting! I'm always so glad when people find something helpful here. I hope you enjoy many happy hours in your greenhouse!

Unknown said...

I finally got around to ordering my roof panels, after being on hold for 20 min. I was informed that I can't order them anymore. I tried ordering more panel clips and I can't order the either. They did suggest ordering from Green House Mega Store. I guess I'll be spending a little more than I planned. Just thought I should let you now.

mudhouse said...

Hi Anetta, thanks for the heads up. By the time I found your post, they'd already closed for the day, but I will call them tomorrow to verify that neither part is available any more(this will be bad news indeed if they've made this change.) I need to find out for myself anyway.

Harbor Freight can be truly awful on the phone. I mean, awful. I've had them tell people that the clips are no longer available before, and when I urged them to call back, they were able to order them with no problem at all. (Maybe it depends which operator you get, but of course that's no excuse.)

I'll call them tomorrow, and I'll post back here either way, with the results of my own Harbor Freight telephone adventure. If roof panels and clips are no longer available, I'll have to modify my blog with the update, so thanks again for taking the time to let me know. Much appreciated.

Back tomorrow,

Unknown said...

Thanks Sheri, I went ahead and ordered 6mm panels from Greenhouse Megastore. I hope the thicker panels won't create too much of a problem. I only ordered enough to replace the broken panels. I found the clips on Amazon but haven't ordered them yet. I'll wait to see the results of your adventure.


mudhouse said...

Thank you, Anetta, for the valuable info. So far I can't even get Harbor Freight on the line; I keep getting a message saying "we are experiencing system problems, and are unable to process your call, try later." I can't even get on hold with them, but I'll keep trying, and will post back if and when I can get to a human being.

I need a new roof too (and walls) so I will soon travel the same road you are. If I end up ordering 6mm polycarbonate, and I find it won't slip into the channel at the roof peak framing, I've always figured I could (very gently) compress the first 1/2" or so of the panel end, using some kind of flat-jaw pliers, so it would slide into the channel. A little tedious, but I think it would work fine. The 6mm will of course provide you with a bit better heat retention too (nice, since I've read more heat is lost through the roof of greenhouse structures, than through the walls.)

Maybe Harbor Freight's customer service (always pretty poor) has finally cratered entirely. I'll keep trying...!

mudhouse said...
This comment has been removed by the author.
mudhouse said...

Back again Anetta. (Had to repost, since I typed a part number wrong.)

I got through to 1-800-444-3353 Harbor Freight. When I chose Option 3 in the phone tree (to order parts) they put me on hold; I bailed after 30 minutes. I tried again, and chose Option 1 in the phone tree, for placing an order. This got me through in about five minutes (who knows if this will hold true for you, though.)

I gave the operator the SKU number for the bag of clips (29457), and she could not find them. I gave her the part number (53), and she could not find them. Uh oh; the SKU number used to always work for me, on the clips.

Finally I gave her the model number for my greenhouse (93358) and then the part number (53), and she found the clips right away. She verified the panel clips are still available, 130 in a bag for $15.99, plus $6.99 shipping.

Then I used the same process to have her look for the roof panel. Greenhouse model number 93358, Part number 60. Using this method, she verified the roof panels are still available for ordering, for $13.99 each, at least for my model of 10x12 greenhouse (93358.)

But remember, these roof panels are the poor quality (in my opinion) Harbor Freight panels, so they won't last nearly as long as the 6mm UV protected polycarbonate you ordered from Greenhouse Megastore, which has a 10 year warranty. Frankly, since replacing the roof is so much work (we've replaced ours once, already) I think you're wise to go with the "real deal" UV protected polycarbonate instead. I plan to do the same, this time; no more Harbor Freight roof panels for me, since they've just proven to be a quick cheap fix for a few my climate.

If you decide to call HF for the clips, I'd suggest using the same procedure. Choose Option 1 in the phone tree to place an order. Then give them a greenhouse model number. (It's on the front of your manual, and there are two HF 10x12 greenhouses, model 93358 and model 69893, but the clips are the same for either model.)

After giving them a greenhouse model number, give them the part number 53 (same part for both greenhouse models.) This is a bag of 130 clips for $15.99 plus $6.99 shipping.

If you order anything from HF, I'd also ask for confirmation that the panel clips are IN STOCK when you place the order, and also ask them to send you tracking confirmation by email. That way, if they don't send you tracking, you won't be waiting pointlessly for something that hasn't shipped. They're supposed to keep panels and clips in stock, sort of, but I don't trust these folks much.

My greenhouse is going on ten years old, and I've come to expect adventures with any HF order. The last time I ordered replacement roof panels, they messed up the tracking info, and at one point I had two orders in their system (one real, one bogus.) It was a mystery when they would arrive, but they did, and in good condition, in a few weeks.

You might be better off ordering the clips from Amazon, as shipping from Amazon is pretty reliable, but the price on the HF clips (130 clips for about $23 total) is pretty good. If you do order some of the clips on Amazon, double check the listing, as some ship from the UK (and I'm assuming you're in the US.)

It's crazy that this is so difficult, but I hope some of this helps. Sheri

Unknown said...

I'm going to try to order them from HF. I checked amazon, the U.S. Company wanted 12.99 + 14.99 shipping for 50 clips.

When I tried before, I first selected option 1 and got a repetition of your call may be recorded. I tried again and used option 3 and was on hold for 20 min. This time I'll try option 1 again. My greenhouse item #69893. If that doesn't work I'll use #93358 with the part number. Hopefully one of them will work. I don't relish the idea of spending $28.00 for 50 clips.

Thanks again for your effort.

mudhouse said...

You're very welcome, wish I could do more. I also noticed on the HF website that you can call them from 5am to 9pm (Pacific Time) Monday through Saturday, and 6am to 6pm on Sunday. So if you can't get through (even using Option 1) you might also try very early or very late in the day.

Fingers crossed for you. (Good thing gardeners are generally stubborn, patient, determined types, eh?)

Unknown said...

I got my clips ordered without any problems.

Now I may have to order more panels. We had a wind storm yesterday and with panels already missing from the last storm, I lost a bunch more. One was across the street went to get it and it blew out of my hands into the neighbors fence, then flipped into their yard. Today I will go out and search the neighborhood to find them.

I really didn't know whether to laugh or cry. So I laughed.

mudhouse said...

Well, I admire your attitude and persistence. Glad you got the clips ordered, but sorry to hear about the escaping panels. That problem (panels coming lose in a wind) is the major drawback these HF greenhouses became famous for, and it's actually the main reason I did this blog. So many people have posted about HF disasters from panel loss (sometimes the aluminum frame is so damaged, after the panels blow out, that the greenhouse is a total loss)...and it's so sad, because the HF manual doesn't warn about this.

Do you have your panels fastened with a screw or two, into the aluminum frame, in addition to using the clips? If I didn't, I know for a fact I wouldn't have a standing greenhouse today. When we replaced our roof years ago, there was one panel we accidentally skipped and forgot to screw to the frame. Sure enough, within a month or so that roof panel came loose (no damage though.) It was the only panel I've had come loose in ten years, so I'm a believer!

I hope you can locate your panels. Years ago I read a joke in a forum that all HF owners should put their name and phone number on each panel. Dark humor indeed...

Unknown said...

I agree with putting the phone number on the panels, my neighbor had 3 in his yard.

No we didn't screw them. I hired a guy to put it up and wasn't aggressive enough to get it done my way. Live and learn. I live in Western Washington, our climate is pretty mild, but we do get some good winds on occasion.

The plan is to screw the new panels and to caulk and screw the roof panels. I also have shade cloth coming. That should help preserve the panels. The first year it was up we had an unusually hot summer.

I gathered the panels yesterday, today I will do an inventory. I think I'm missing one of the small panels from the gabled end. It may be in the next town!!

I'm going to have to wait till some dry weather to put it back together. That could be a long wait. We are known for our Rain. March we were 6inches ahead for the year.

Well, at least I won't be bored.

Unknown said...

Great blog! Thanks so much for the tips. I just called and ordered the clips for our upcoming HFGH project. We dug out and graded the area in preparation for a foundation install, now waiting for it to stop raining so we can pump it out and get going on this project. The down time came in handy, as I read this blog and ordered more clips! Thank you so much for all the effort in keeping the blog up to date!

mudhouse said...

You're very welcome Patrick! I know Harbor Freight has made a few changes to the kit over the years (some parts have changed a bit) but I'm glad the blog overall can still be a bit helpful. I hope your weather clears soon, and good luck with your build. (I wish you could send your rain here to the desert, we'd put it to very good use!)

Unknown said...

It's a year later and I still don't have my greenhouse repaired. I was wondering if you had replaced your wall panels. I e-mailed them to see if the rear wall panels were available, they say they are not. I also need to fix my doors, that is a special order and it is going to take time. I have the time. I'll call them and try to order everything was just wondering what kind of luck you had

mudhouse said...

Hi Anetta,
I did replace all of my south facing side wall panels last fall, since they were in the worst shape. I had no trouble ordering them from Harbor Freight. But, I haven't tried to order any rear wall panels yet. Also, my 10x12 greenhouse is the Model 93358 version. I suppose it's possible they are no longer offering the panels for your Model 69893 version? I'm sorry, I don't know.

I'll have to replace my roof this summer for sure, but I'll probably order better quality twinwall polycarbonate from a greenhouse supply company, to avoid the deterioration problems of the Harbor Freight panels. They'll cost a lot more, but it's just too much work to keep replacing the roof with the HF panels that don't last well in my sunny climate (and I'm getting old, and wary of ladders.)

My order for the side wall panels for my GH version went very smoothly, and they arrived quickly in good shape. I hope you're able to order the parts and panels you need...

Unknown said...

Thanks so much for a wonderful blog. I just bought mine and felt overwhelmed until i read your blog, shame it's not in book form and included with the greenhouses.
It's April 9 and we just got 5 inches of snow in central WV so insulating the greenhouse is one of my main concerns. If you have any other links to more info. It would be appreciated. Also, where do you buy most of your greenhouse parts.