I'm going to finish one corner of my basement and want to insulate the two adjoining exterior walls so that the space will stay warm in the winter. The wall was painted a few years ago and the paint is peeling in places. I plan to scrape these sections to ensure the adhesive sticks well when I add XPS insulation boards. My intent is that the XPS insulation act as a vapor barrier.
Is it necessary to scrape away all of the paint, or will removing the loose flakes be sufficient?
After the insulation I'll add a stud wall right against the XPS, with batt insulation in between the studs, and drywall over that.
The home is 100 years old but a poured foundation was added at a later date. It is a shallow basement with no drains. We've had a wet winter but this corner has stayed dry (some seepage in another area due to an ice dam outside which I remedied).