I'm renovating a room in an old part of our house that has been additionally insulated by previous owners.
I've always felt a strange odor in this room and decided to get to the bottom of it. The smell has been quite heavy and hard to define. It doesn't smell like a root cellar but more dirty, musty.
The room's exterior walls are built as follows:
From inside out:
Drywall
Polyethylene plastic
Studs/insulation (yellow)
Masonite
Sheathing
Paper
Stud Frame/Insulation (gray)
Thicker paper (feels like asphalt paper type)
Panel
Insulation
Paper
Outer paneling
I've accessed the frame itself and can visually inspect the thicker paper that's here behind the insulation.
It feels fine BUT it is most likely that paper that is the source of the smell.
In the middle of the image is an old door opening sealed with regular weather-resistant paper many years ago before I owned the house.
My plan now is to restore the wall the same way as before but replace the sheathing with OSB and instead of masonite, put OSB and drywall as the room's surface layer. In spring, I'll tackle the wall from the other side and take down the outer paneling and so on to access the paper.
My question is, what do I replace this foul-smelling thick paper with?
A bit sandy on the surface ??
In that case, it's roofing felt, probably used whatever was available.
It seems like there's a lot of layering in those walls, I don't think you need to replace it with anything at all.
