Hi poaky1, I definately, absolutely needed extra clips for my HF 10x12 greenhouse, as well as screws through the panels into the frame. I can positively state that my greenhouse would not be standing today if I had not taken these steps. I did not caulk my panels in place, because I like to be able to remove them if needed. So, my solution was extra clips and screws, but Saturn3600 (above) used both extra clips and caulk, on his or her 6x8 greenhouse. There used to be more frequent threads around here, years ago, about Harbor Freight disasters, back before people knew to take a few extra steps to make the panels and foundation more secure. Here's one, for example. Greenhouse Disaster HFGH 10x12 You're the only one who can decide if it's worth the extra $9.99 plus shipping, for a package of 72 clips. To me, a little extra insurance seems like a no-brainer. Even if I lived in a climate that did not have uniformly high winds, I would not want to risk the loss of my greenhouse, or plants, but that's just me. An unusual gust of wind or errant windstorm can happen anywhere, even if it's not the norm. You can order extra clips by calling the 1-800 number on your Harbor Freight manual. For the 6x8 greenhouse, Harbor Freight uses the part number 46 for the panel clips. The SKU number is SKU number 27339, for a set of 72 clips, $9.99. Hope this helps, I know some of these decisions can be confusing. I sleep better if I err on the side of stability and safety (I really hate surprises.) I think they usually ship the clips pretty quickly.

I use a $50, 1500 W thermostatic, oil-filled heater for my 10 X 15 GH in Zone 8 and it works fine to keep things from freezing. In fact I generally have it on the 750 W setting and that keeps things about 38F even when it's in the 20's. For your GH, in your Zone, a heater like this should be all you need. Just make sure you have a dedicated 15 amp circuit with nothing much else on it. If you don't have an outlet next to the greenhouse to plug the heater into, you'll need a 14 gauge (or preferably a 12 gauge), outdoor extension cord to avoid electrical/fire hazards. As for flooring, bricks (or pavers) on sand are great because spills drain immediately. If you do concrete at some time, make sure you have a drain in the center. Do a search in this forum and you'll find a lot of posts on the subject of GH floors.

Amazing the price is less than you paid six years ago. Good thing is, you'll breeze right through putting this one together. My 10x12 is about 6 years old too, replaced the roof panels not quite two years ago, will replace most of the wall panels this summer. All else is rocking along just fine. I think these are a great deal, too.

thanks