Help identifying sheathing on 1976 house, or lack there of…
DanaET
| Posted in General Discussion on
We are doing some changes to a bathroom, pulled down the drywall and then decided to replace the old insulation. Behind the insulation, instead of finding something like OSB/Plywood, or some sort of fiber board, we just found what looks like tar paper and on that other side of that is the brick.
I’ve attached a close up picture, hoping I am wrong and it is some other kind of sheathing that used to be used. It is paper thin(1/16 inch thick) and black. The house was built in 76. I’ve seen some other threads where people have found something called Celotex sheating, but it looks to still be much thinker and rigid then what I have.
Any ideas? I am a little concerned about the house structure now.
Replies
Yep, that looks like tarpaper. The insulation board you mention is 1/2" thick.
It's not an unheard of pracitice but shouldn't have been happening in 1976. I have seen small houses built in the last 10 years with no sheathing, just tyvek over the studs which is clear malpractice by modern standards.
How serious an issue your case is depends at least some on your location. In an area with potential high winds or eathquake issues it matters more.
Of course it could be that you have inlet bracing as needed or plywood corners. That would take a bit of work to determine.
I'd think you can take some comfort in the fact the structure is still intact.
This would have been entirely normal for a house built before WWII, a bit unusual to see in one built in 1976.
Very likely the builder was "old school", and used let-in bracing or some such rather than sheathing to stiffen the structure. In any event the brick veneer should provide a significant amount of rigidity.