Does anyone have experience with or an opinion of the Dow Powerhouse solar shingle and cathedral ceilings/ roofs?
JoeUSAF
| Posted in Green Products and Materials on
The cathedral ceiling/roof is unvented, closed cell insulated. Will this solar shingle properly vent moisture upward from the plywood decking? Will there be any problems with running the multiple wiring conduits to the inverter in the basement?
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Replies
Joseph,
Q. "Will this solar shingle properly vent moisture upward from the plywood decking?"
A. No. Photovoltaic roofing shingles are not vapor-permeable. But neither are ordinary asphalt shingles or steel roofing. If you want your plywood roof sheathing to dry to the exterior, you will need to create a ventilation gap above the plywood. This can be done by installing 2x4s from soffit to ridge, laid on the flat, with one 2x4 on top of each rafter. This will create a 1 1/2-inch deep ventilation gap. Cover the 2x4s with a second layer of plywood or OSB roof sheathing, and then install your roofing underlayment and roofing.
Q. "Will there be any problems with running the multiple wiring conduits to the inverter in the basement?"
A. If you have an electrician on site who is capable of following the instructions provided by Dow, the manufacturer of the PV shingles, you should be fine.