Jane Metzger
We are finishing a garage. Our roof is made of trusses. We would like to put on a metal roof. The pitch is 12/12. Question we have are: Do we use purlins or sheathing. We purchased 3/4 inch OSB. Our contractor says we should use purlins. My husband wants to use the OSB. Which is better? The sheathing will be more expensive to put up (labor wise). We are more worried about condensation (This will have a living space below. Also, is 29 gauge strong enough? We have put a lot of money into the building itself and don't want it to end on a bad note. We plan on using spray foam insulation directly to the underside of the roof. We are really confused.
Todd Miller
Isaiah Industries, Inc.
Sheathing will help guard against condensation and also be better in terms of the spray foam application.
Eric Novotny
An informed customer is the Best Customer!
+1 I always recommend sheathing. Spray foam is not a must but it is the easiest way to insulate the roof deck if you are trying to make it the conditioned plane.

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