Put finger through wall to siding

[dh001]

Hi,

I'm renovating my basement. After taking out the drywall and insulation I noticed a wet area on the tar paper. I made a hole in it and noticed some wet pressed wood. I was able to put my finger through this to the aluminum siding.

The house was built in 1989. I live in Ottawa, Canada.

Some questions
- is it normal for a house not to have plywood on the exterior wall? It appears to be just building paper with some pressed wood thing
- what do I need to do to fix this?

[HayZee518]

somewhere on that wall you have a water leak or water is finding its way to that particular place of the wall. the sheathing you are speaking of is plain old chipboard that doesn't have a waterproof adhesive [ the stuff they used to make the chipboard panels] you are looking at a labor intensive job.
the exterior siding has to be removed. the tarpaper has to come off. you need to remove the faulty sheathing. you need to replace the sheathing, rosin paper and the siding. way too much for a DIY. Call a contractor.