I live in a fire danger area and have a woodshake roof. It’s T&G topped with plywood and final layer is 1/2 sheetrock which is used for firestop. Would it be ok to lay asphalt shingles on top of the firestop as long as the nails penetrate the plywood?
i second that NO
Good question. I don’t know what the answer is. It would be a funky system if you did.
You fellas that are saying no, why not?
ELk used to make a product called versa shield (spelling) came in 4 square rolls. went down like felt paper and gave you a class A fire rating.
I think the sheetrock would absorb too much moisture, even with a vapor barrier over it.
This would be moisture coming from rain & external elements AS WELL as trapped attic moisture.
I say nope.
use densdek not sheet rock. its denser than regular sheet rock.
I removed a roof similar to one you mention and the sheetrock was in perfect condition. It was also signed off by building and safety when we re-roofed it with asphalt shingles. Still in perfect shape today even with 80-90 mph head winds. Just make sure your nails penetrate the plywood.