First, it's best to assemble this frame on a day without wind.
Second, throughout the kit, the bolts are inserted so the head is on the outside of the greenhouse, and the nut is on the inside of the greenhouse. This allows the panels to lay flat against the bolt heads on the outside of the greenhouse.The floor plates (Parts 1,2,3,4,5,6) get assembled and sit on top of the steel base. It seems like they should get bolted down somehow, but they don't. They're basically "clamped" to the steel base by the small Hold Down Connectors (part 47) that you'll use at the bottoms of the corner posts and wall studs.
It's easy to get confused about how to orient the four corner posts (part 7). Each post has a total of two holes drilled in one end, and a total of four holes drilled in the other end. The end with two holes goes down, and the end with four holes goes up.
Each post is oriented so the two flat flanges point towards the greenhouse, and the two flanges with folded-over edges point away from the greenhouse. The photo above shows a corner post from the outside.
Now comes a case of "do as we say, not as we did."
When the corner posts went up, they were wobbly. They got even more wobbly when we added the weight of the ceiling plates to the top, which is the next step in the manual. Then a breeze sprang up, and the structure got very unstable. Running, yelling, grabbing of posts. To prevent damage to the frame, we anchored the structure to our nearby house rafters with scrap wood and wire.
I found out later what smart people do to avoid this problem:
TIP: As you put the corner posts up, temporarily attach the diagonal braces (parts 79 and 80) for stability.
Have a look ahead at page 11 of your manual. See how the diagonal parts 79 and 80 are attached to the top of the corner post, and to the base? Put them in place now; attach a part 79 AND a part 80 to each of the four corner posts. The aluminum this kit is made from is quite soft (softer than the stock aluminum the box stores sell, for example.) It's possible to for the posts to bend if they're allowed to fall over under stress.
This is just a temporary trick to give you stability at this point, and you’ll have to remove these diagonals when it’s time to add some of the vertical wall studs. Until then, you’ll have the support you need to add the top (ceiling) plates all around the structure. If you’re assembling this out in the open and a breeze springs up, you’ll be glad those diagonal braces are in place. This is also extremely helpful if you're building this greenhouse by yourself. It's easy to bolt and unbolt these pieces as needed, so go for the stability and peace of mind (trust me.)
That way you won't have to do anything that looks as silly as our baling wire solution above.
The Front Ceiling Plate
On page 7, assembling the pieces for the front ceiling plate (over the door) is confusing. You assemble them on the ground first. To figure out which side is up for each piece, it helps to look at the drawings in the parts list on page 19. If you orient the pieces like they look in the parts list, the directions make (a little) more sense.
In my manual, on Page 8, step 7, it said to “attach the Front Ceiling Plate to the inside of the two Corner Studs.” This is impossible; the ceiling plate can only be attached on the outside of the two corner studs. I've been told this error has been corrected in more recent manuals (although it still shows this error in the PDF file manual on the Harbor Freight website.)
The photo above shows how the ceiling plate looks installed.
The Very Annoying Two Rear Wall Braces (Parts 31 and 48)
Everyone seems to agree this is a bad spot in the assembly. Page 8, Step 10. You’re joining two Rear Braces (part 31) together into one 10’ wide piece to be installed at the top of the back wall. The two Rear Braces are positioned parallel to each other, partially overlapping, and connected by two Stud Connectors (part 48.)
The flat side of part 48 will be against the rear braces, and part 48 will be on the outside of the greenhouse.
Use long bolts in the holes of the Stud Connectors to attach the Rear Braces together, and use a strut bolt (part 78) in each end of this long assembly. When it’s assembled and installed, it looks like this (standing inside the greenhouse.) But there's a problem…let's call it a Bad Design Alert!
The instructions tell you to fasten both ends of this Rear Brace assembly to the bottom hole of the triangular Corner Bracket (49) at the corner posts, as shown to the right.
This doesn’t work well. One end of this newly assembled bar is higher than the other, so to keep things level, the attachment point on one side should be slightly higher than the attachment point on the other side. That’s logical, right?
Well, unfortunately, you can't attach this in a logical way. You do need to use the bottom hole on the Corner Bracket, just as the instructions say, on both sides. This means that the whole assembly is be rather unlevel. It looks a bit odd, but it does work.
In case you're as stubborn as I am, let me save you some time. We tried to correct this dumb design by attaching one end of the assembly to the bottom hole of the Corner Bracket, as in the photo above. On the other end, we thought we were being brilliant by ignoring the directions, and attaching it to the corner bracket using the second hole up from the bottom, so it looked like the photo to the right.
Great! This makes everything nice and level all across the back wall. But it won't work. The problem is, a few steps later you’re attaching Side Diagonal Strut (part 80) onto the same corner bracket area, and it simply won’t fit if you use the second hole for part 31 as we did to the right.
So, defeated, we had to attach both ends to the bottom hole on the Corner Brace, as shown in the photo to the right, just as the instructions directed. So, this is how the back left corner is supposed to look, even though it does make the rear brace assembly look unlevel.
Once you get this assembly attached at both ends, using the bottom hole in the Corner Brackets, you can loosen the bolts and wiggle things around so they look more level. The aluminum bracing has enough flexibility to be a little forgiving.
One more tip about this pesky area: when you start attaching the back wall studs to this Rear Brace assembly, the studs slide into the Stud Connector (47). One stud slides up from the bottom, and a short stud slides down from the top. The Stud Connector joins the two studs into one. When you slide the bottom stud into place, position it so it only covers up (roughly) the bottom two holes of the Stud Connector. You’ll need the top half of the Stud Connector clear to accept the other stud. Here’s what it looks like after the bottom stud is in place, standing outside of the greenhouse.
By the we had this Rear Brace assembly all assembled and wiggled around so it didn’t look as obviously crooked, the joint between the two studs actually ended up a bit higher than halfway on the stud connector, as you can see in the photo to the right.
One person I read about decided to discard this whole Rear Brace assembly and bought a 10 foot wide piece of aluminum angle iron to use across the back wall instead. After wrestling with the design problems of this back wall area, I can see the benefits of that idea.
However, it is possible to get the pieces together so they'll do their job...it just looks kind of funny.
Now, on to Assembling the Wall Studs (page 9) And The Famous Bolt Quantity Error!
Page 9 contains an error that's caused much aggravation. This page explains how you attach the wall studs to the top and bottom of the frame. As you attach each wall stud, you include extra bolts in the track that “float” until they’re used to secure braces you add later.
The error is in the bold note marked “IMPORTANT:” by the Figure D illustration. It tells you how many of these extra bolts to insert in each wall stud, but the quantities are wrong.
Basically, the instructions tell you to insert fewer long bolts than you'll really need. If you follow the instructions as shown in the manual, you will have to take things apart later to add more bolts to many wall studs. Arrgghh!
In earlier kits, they didn't even include enough long bolts to complete the construction. People had to go buy more. In my kit, I had exactly enough long bolts to complete the construction, so they've probably started correcting the number of long bolts shipped in the kit. However, if you have the 05/06 manual, they have NOT corrected the instructions that tell you where to use them. Nice, huh?
So, I made a list of the correct number of bolts needed to install with each wall stud, referring to the illustration on page 9. I kept that list with me as I put up the wall studs.
That list is shown to the right, and you're welcome to copy or print it. It's pretty ugly, but it should prevent you from needing to take things apart later to add more bolts to the wall studs.
I wrote these bolt lists to read from the top of the stud to the bottom. In this list, (SH,L,L,L,L,SH ) means a short bolt attaching the top of the stud, with four long bolts floating, and a short bolt attaching bottom of the stud.
TIP: Since you’re sliding bolts into the tracks in the wall studs at this point, you could also include extra bolts that will remain free-floating in the track. If you plan a bit, you could use these to attach brackets for shelves or other things. Frankly, my brain cells were dying by this point, and I decided just to get the walls up and use T-bolts for greenhouse enhancements later. But, it really is a good idea, and lots of people have been bright enough to take advantage of it.
TIP: As you install each wall stud, you can also install the small Hold Down Connector (part 47) at the bottom of the stud. Oddly, the manual has you go back and add these parts later in the process (unscrew the bottom nut, add the part, screw it back). This is silly. There’s no reason not to do it now, and it saves you a step later.
The photo to the right shows how you attach the bottom bolt through the Hold Down Connector (part 47) and leave various additional bolts "floating" in the groove above. The additional bolts (of varying lengths, depending on which stud you're working on) are ready to be slid up the track to install braces later.
For general information, here's what the OUTSIDE of a top FRONT corner looks like at this point:
And, here's what the INSIDE of a top FRONT corner looks like at this point:
The wall studs are up, and the front diagonal braces are in place, on either side of the door area.
Tip: Before you start adding the horizontal wall braces (parts 30,31) it's a good idea to stop and check again for squareness. You can measure diagonally from corner to corner inside (hopefully the measurements are equal.) We also used a level on each corner post. You can loosen bolts to make adjustments as needed. Frankly, you can't check for squareness too often. It's much easier to correct a bit as you go.
Struts and Braces
(Oh joy, different types in different kits!)
Remember when I mentioned that Harbor Freight keeps making changes to this kit? Here's one.
Apparently there are older kits out there with Diagonal Struts (parts 79 and 80) and Horizontal Braces (parts 30, 31, 32) that are shaped like like angle iron, with one large flat side and a small flange on one edge. And, there are newer kits out there with Struts and Braces that are made of hollow stock that's rectangular in cross section, with little plastic caps on the ends. I have the newer type, as shown above.
Who cares? Well, the angle type is thinner, so it can be fastened with short bolts, but the thicker hollow type (like mine) requires a long bolt. This means I have to use longer bolts than the manual states, at every point where a Diagonal Strut is attached. Joy!
In my drawing of which bolts to use for the wall studs, I assumed you have hollow Diagonal Struts shaped like mine. If you have the thinner angle type instead, it should still work; you'll just have some bolts a bit longer than you really need, at the bottom of a few studs.
TIP: See the little sticker with an arrow on Part 30 below? When you assemble the Part 30 braces, point the arrows into the corners of the greenhouse. If you don't, the holes won't line up correctly.
Page 10, step 8. The black plastic Gutter End Caps (part 73) snap on the ends of side ceiling plates, leaving a small gap for the water to flow out.
I see other people have used these, but on my kit, the gutter walls on the ceiling plates are spread too wide to fit the dinky plastic pieces. The plastic pieces keep popping off. We could probably bend the gutters to fit, but I think the small water gap in the plastic caps would probably get quickly clogged anyway. Fearing standing water in the gutters, we just left them off.
Here’s how the structure looks with the walls up, and wall struts and braces in place.
Click here to go to Part Four: Assembling the Roof, Windows, and Doors.