underlay with metal roof and spray foam

Guest User
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?
Todd Miller
Isaiah Industries, Inc.
I would suggest underlayment, and building codes require it.
Eric Novotny
An informed customer is the Best Customer!
+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.

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