Insulating attached garage – drywall over sheathing or vice-versa?
sackofhammers
| Posted in General Questions on
I’m insulating (rockwool) the wall between our mid-century home and the attached garage. Garage was built with the home in 1964. I intend to add strapping to the 2 x 4 wall to make the wall effectively a 2 x 6 wall.
I’d like to finish the wall with exterior-grade siding (SmartSide or similar), which brings me to my question:
Can I put this over my type-X drywall (not present, I will install this) without affecting the safety rating of the drywall?
Thank you.
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Replies
The drywall is still a fire barrier if you put something over it. You can, for example, put a piece of plywood over the drywall to hang hooks on if you want, and the drywall is still there and still "counts" towards the fire rating of the wall as long as you don't cut holes in it.
Where you could potentially have issues would be with surface flame spread on the garage side, but I don't think there are any code rules about that in this situation.
Bill
Thanks for the reply, Bill.
I expected this would be the case (it doesn't matter what's burning on the other side of the drywall, does it?) but wanted to get an expert opinion as mine isn't.
Cheers.