Douglas Alpenstock wrote:
Mike Haasl wrote:I think you will want to seriously round off those wood corners at the edge of the roof so it doesn't wear/tear the plastic prematurely. Rounding off the long edges of the roof rafters would likely help as well.
Agreed!
Another trick greenhouses use is to cover the wood support members with a strip of plastic. That way, when the wind and expansion/contraction causes the cover to move, it's plastic-on-plastic, which is low friction, extending the life of the cover.
Mike Haasl wrote:I think it will flow off nicely. The only place it might pool is at the lower edge of the roof. So if the plastic is tighter at that lower edge (where it goes from 15 degrees to 90 degrees) it might act like a dam to hold back a puddle.
I think you will want to seriously round off those wood corners at the edge of the roof so it doesn't wear/tear the plastic prematurely. Rounding off the long edges of the roof rafters would likely help as well.
Thomas Michael wrote:The poly will be 1 solid sheet? It would work with even less roff pitch. As long as it is strong enough to support the snow load.
I have a ~20 year old green house in California with a roof very much like that. It is about 20° though, recovered every 4 years with a new 18x20 6mil greenhouse sheet. Works fine. The plastic fails on the ridge and each rafter. I assume because of the extra heat.
Where are you? I would not use 6mil poly in snow country my sister lives in South Dakota and I have seen pix of golf ball size holes in greenhouse poly from hail. There is 10mil fiber reinforced uv stabilized gh poly available. Tom