I posted a question earlier about using Thoroseal as waterproofing on an outside basement wall. Your reply was that it was not a good product for this. The builder has now painted the outside foundation wall and in an area about three feet above grade, the paint has started to peel off. The builder says this has nothing to do with the wall being damp but was caused by something else such as not using enough sand in the original mix. The paint is not peeling anywhere else. What do you think?