I have done something similar to help support the weight of snow. I have a 2x4 beam going down the length of the grhouse at the top, inside, that is supported by 2x4's that then are attached to the shelves.
One of the grhouses got racked when they were building it, so down the length of the inside, on one side, there is a similar 2x4 beam supported by 2x4's that either hit the ground or the shelf. That grhouse is 100' long. I think it works great.

What does HFgrhouse stand for? What do you consider high winds-that would start to affect the structure?

Hi, Sorry... HF is Harbor Freight. Hurricanes on the coast can cause 60 mph winds here. We're about 35 or more miles in from the coast and 15 from Chesapeake Bay I guess.

Here is a link that might be useful: HFGH 10x12 greenhouse

Do you have a location where you could put it that would provide a wind break.
If not then reinforce the hell out of it. It is much better to make it stronger than necessary than to find it in a twisted pile of metal.

I have a different brand of aluminum frame greenhouse, but the design is similar to the HF GH. Mine came with flat aluminum struts that were about 3/4" wide about 6' long, and they are screwed to the inside of the frame to provide additional bracing. There are two in each corner and each pair runs diagonally from the upper corner to the base (they basically each span one corner window panel diagonally on the two walls that form the corner). There are also 4 of these struts that run diagonally to brace the roof. Because they are installed diagonally they provide incredible stiffening. My greenhouse just survived a 70mph freak storm with no problem. Below is a link that diagrams how these reinforcements are placed.

I would think it would be relatively easy to get some aluminum stock and cut your own reinforcing struts. It could be relatively light gauge because it is not supporting a load, but simply providing tension to the structure. This might even be easier than trying to build a bulky wood frame to reinforce your HF GH, and this approach doesn't take up any room.

Here is a link that might be useful: {{gwi:286612}}

I agree with kudzu. I wouldn't think that you would want to take up space with wood. The 10x12 is still a very small greenhouse. Use aluminum stock or EMT like laserfan.

Posted by kudzu9 Zone 8b, WA (My Page) on Thu, Jan 4, 07 at 16:05

I have a different brand of aluminum frame greenhouse, but the design is similar to the HF GH. Mine came with flat aluminum struts that were about 3/4" wide about 6' long, and they are screwed to the inside of the frame to provide additional bracing. There are two in each corner and each pair runs diagonally from the upper corner to the base (they basically each span one corner window panel diagonally on the two walls that form the corner).

What you are describing is exactly how the HFGH is built.

Is the HFGH 10x12 being built stronger now?

I'll give up a little space for a 2x4 frame to save having it destroyed.

From what I've read, it seems the wind can cause it to twist and thus lose panels. Once a couple panels are gone, the wind is inside and blows out the rest and can destroy the structure.

I'd like to strengthen it so that it won't twist. Caulking and screwing the panels in should help provide a little structural stiffness to the frame. I just don't know that it's enough.

I have a very twisted view on life. I would put the pressure treated wood frame on the OUTSIDE of my HFGH if I had one.

An exoskeleton, you can then toss shade cloth over it, a tarp, a pool cover.....

Really seriously thinking of building an EMT framed hoophouse over the top of my greenhouse (without any covering.) So that when disaster strikes I can get a tarp over it easily.

Posted by troykd 7b SE VA (My Page) on Fri, Jan 5, 07 at 10:19

Is the HFGH 10x12 being built stronger now?

NO it has always had the diagonal braces in it.
Some people just have a misunderstanding as to why it can fail and they need to do more reading and make fewer assumptions

The exoskeleton probably would be ideal but if I built it, it would just be to ugly.