Written on: 13/09/2011 by smiler03 (6 reviews written)
Firstly I want to address the problem some people have had with wind damage.
You're almost certainly not assembling it correctly. The polycarbonate panels fit very neatly to where they should. Make sure that they tuck under the roof line, this alone holds them in place quite well. You should then have about 4 or 5 clips for each side (left/right) of the panel. Spread them evenly over the length of the panel. If you're doing it correctly then the clips snap firmly into position. A fair amount of force is required to do this. If they aren't pressing down very hard onto the edges of the panel then they aren't doing anything and the panels will blow out, in a breeze. You also need to make sure that all nuts and bolts are tight, more than finger tight.
We live in the North Pennines in a VERY windy area. There are wind turbines galore in our area. Our greenhouse is also exposed to the prevailing westerly winds.
Taking into account our very exposed position I bought an extra set of clips, a pack of 50 is about £5 on eBay. Use those and you've already made your panels much more secure. I then had another idea and used clear silicone sealant around every edge of every panel. Applied using one of those gun thingies. This stops virtually any wind getting in through the roof. It takes a while to do these two extra jobs but at the end of it it will be very very wind resistant. The cost of about £15-£20 extra is well worth it, it represents about 7% extra on top of the greenhouse cost.
Another hint: I place a small but heavy slab against the door when there are high winds.
I have a home weather station which is actually mounted on the greenhouse (at the front at the top). As in all gales we also get gusts as well. I have logged consistent wind speeds of 65 mph with gusts to 77 mph. Hurricanes are wind speeds of 73 mph and up.
The reason I am writing this review is that after 6 years of no problems at all, a panel blew out during the aftermath of hurricane Katia hitting the North East of England (12 Sept 2011). The edges of the panel have cracked so it needs replacing. I can and will repair it, spare panels are cheap, about £6, but P&P doubles that. Still, I think 6 years of use and one panel aint bad at all!
Another hint: DO NOT go to B&Q for spare panels, they seem to want £23 for them!