Question

I am building a screen house with a metal roof -- do I need roof felting, and if so, is there a non-asphalt nontoxic alternative?

Asked by maia Harris
Cummington, MA

The roof will not need to be insulated. it seems to me I can screw the metal directly onto a simple wooden framework. I have chemical sensitivity and would like to build without asphalt, rubber or plastic in the roof, all of which heat up in the warm weather and cause outgassing. I'd prefer no felting if possible.

Answer

Generally speaking, I would always recommend using a separation layer (including air-gap) between a metal roof and a wood/plywood substructure since a reaction between wood treatment and metal roofing might occur and cause future damage.

A great product to use as a separation between the metal and the substructure is the so-called Sharkskin. Please review the information of the manufacturer to determine if this product will work for your project.

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.