I am installing a metal roof on a 12 12 pitch over a 1" solid wood substrate
I will be spray foam insulating between the 2x10 rafters under the substrate.
Do I need to use an underlay beneath the metal roof or can I install the metal roof right on the wood since there will be no airspace?
Guest User
2012-08-06 20:17:04.000000
I would suggest underlayment, and building codes require it.
Todd Miller
2012-08-06 20:36:47.000000
+1
Gotta use underlayment.
Also recommend that you put some underlayment or rigid foam in the rafter bays and they spray the roof. If you spray directly to the sheathing/decking, any future roof work or wood replacement will take the foam with it.