We moved in to this house 6 months ago. There are a few issues with my some of the exterior basement walls. The house is 47 years old, and the basement walls were painted quite a long time ago. There is indication of moisture penetration, but using the patch test, there was no condensation withing 2 days (I'm guessing the problem was fixed). There is effervesance, what looks like mold growing and the paint is being pushed off the walls. Is it safe to use a paint stripper on the concrete? Should I remove the mold first?