The wind made mincemeat out of my hoop house again. OK, that’s an exaggeration, but we had gusts of 30-40 mph and they were enough to de-skin the hoop house for the second time. I’m beginning to understand that there is a basic problem with the design, or at least my execution of it.
My version is based on one by Tod Hanley, but I used 20 foot PVC hoops and he used 24 foot square steel tubes. He needed a tubing bender to build his. I didn’t. The hoops are anchored by being placed over rebar lengths that are driven into the ground. The plastic is anchored at both ends and held down by ropes parallel to the hoops on top of the plastic. This way the plastic is free to be lifted up for ventilation and is held in place by the rope tension. You can see how it works in this photo (from http://www.kerrcenter.com).
The flaw seems to be that the wind can raise the sides up too, and once it gets inside, there can be enough force to turn the thing into a kite. In my case this past weekend, all the rebars on the east side of the house were torn out of the ground and flung as far west as the ropes would allow. It must have been quite a sight.
I’m not sure what to do about it. I could anchor some skirt boards along the ground and fasten the plastic to them, but that would put the kibosh on raising the sides for ventilation. I may just build some 3 foot sidewalls and fasten the PVC hoops to their tops. Ventilation could be built into the sidewalls. Hmmm, not a bad idea. I’ll have to check out the $$.