@FrankMosher, yes I wish I had known more about greenhouses before I got this one. The company I got it from is in VT and claimed that it was built to hold up against high winds and heavy snow, but until this happened I didn't realize how weak the PVC really is. This greenhouse has been through a lot already like I said earlier, and last winter was a nightmare just to try to keep it from getting buried and crushed by all the snow (here's a picture of it from last January!). If we had a heavy snow overnight I would get up a couple of times to clear it off.
Once the FiberFix tape cures it won't come off, but I'm already having doubts it's going to hold...it turned windy right after I taped it and the pipes are bending and looking pretty weak. I wish I had thought of putting something inside the pipes before I taped them this time. That would have helped a lot!
Right now I'm just focusing on getting it through another winter so I have something to start seeds in next Spring. It's a little late in the season for a major rebuilding project. But I will keep your advice in mind. The rigid polycarbonate sounds like it would be a lot better here!
Thank you!!