Have purchased a home with large open and unfinished "crawl space", like 4' high across low end running to 12' high on the other. Gravel over dirt, sloping as you go. Would like to go forward with plans for a basement room, but notice the cement walls, especially on exposed air portions, have very heavy condensation, dripping wet a lot of the time. Several vents in the walls, which open/close automatically according to outside temp. How do I stop this condensation? Could it eventually weaken the structure in some way?