Tar Paper on INSIDE of exterior plywood sheathing?
Hey there! First post here as I’m going crazy trying to find an answer to this.
I’m DIY renovating a house built in 1977, located in coastal British Columbia. I’ve removed drywall and insulation to find most of the walls (upstairs and downstairs) have black paper in the wall cavity against the exterior plywood (see photo).
A couple walls have it installed outside the sheathing, as I would expect, but only on the lower floor near the covered car port and entry.
I’ve checked that between the ply and siding (siding is wood based panelling from what I can tell), there is no paper or house wrap of any kind, and no rain screen – unless the area I checked (by removing the dryer vent) is an anomaly.
The house has really good roof overhangs on the front and back, and the sides are adequate, so I haven’t seen rain water hitting the walls at all unless the wind is really really blowing.
My dilemma is: should cut away the paper and eventually replace it with house wrap outside the plywood once I redo the siding, and add a rain screen (probably within 10 years). Or should I leave it? I imagine adding house wrap later will create a weird problem, having two layers of paper with plywood sandwiched in the middle.
I’ll be adding a 6 mil vapour barrier before hanging new drywall, so I’m worried about moisture getting stuck in the walls with so many layers!
Anyone know why they would have installed the paper on the inside, and what I should do going forward? Any help would be very much appreciated!