I'm a first-time home buyer and I've come across an issue with the wall of my attached garage. I'm really not sure what I'm looking at. Can anyone break it down for me? Here's the link to an image of the situation: https://imgur.com/a/M8iouSn.
1 Answer
It looks like you have fiberboard sheathing, which was pretty standard before they started using OSB. Some of that material might even have asbestos in it, but usually it doesn't. There are also signs of leakage or wicking, indicated by the water stains and rot on the wall. It seems like someone might have tried patching it up with spray foam, but it's tough to say without seeing it up close.

Have you done anything to fix it yet? How urgent do you think it is to address those water stains?