Metal Roof Over Purlins

I have recently had a small cabin built. It has a Metal R Panel roof. The builders constructed the roof with the metal attached directly to purlins instead of any type of solid sheathing. I was not too sure about this. They said they do it all the time. I love the cabin otherwise, but this has worried me. Mainly I have been reading about condensation issues, and I am not quite sure hoe to go about insulating it. Its a open style roof, meaning no closed in ceiling or attic space. I am not too worried about ice and snow here in Texas but it is quite humid, and in the summer we get days at 100+ degrees. I have talked to a company that specializes in the spray foam insulation. He wants to use open cell foam? Of course they are telling me the way to go is to spray directly to the underside of the metal and purlins, and "they do it all the time". This is just a small weekend/vacation cabin so not our primary residence. Any suggestions or comments would be greatly appreciated. Thanks...		Guest User 4/9/2016	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/21119/find/
I agree that spray foam is a good option at this point. The unfortunate part is that it will make things more difficult if the roof is ever replaced. However, you want to use closed cell foam not open cell. Open cell foam allows vapor to permeate it, which would still allow condensation. Closed cell foam acts as a vapor barrier.		Todd Miller Isaiah Industries, Inc. 4/9/2016	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/21120/find/

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.