Interior basement walls are concrete block.Years ago waterproofing contractor sprayed drylock-type substance on walls. Now sweating is causing peeling/effluenscence (sand)between block & drylock at watertable. Block seems fine, but very unsightly. Could this be more of a problem than just cosmetic? Can I sc**** & fill with concrete? I have a dehumidifier as it is a very damp basement.