My grandmothers house is about 100+ years old and the walls in the basement are the kind that are like "shelves" on the top and come down the sides. All are red brick with concrete over them. Some of the concrete came off so we concreted over the. I painted dry lock when dry. I have yellow spots coming through, and parts where the new concrete was, is still wet after 2 days. I haven't put on a 2nd coat yet, but am wondering why the yellow is coming through (don't know what it is) and will it every dry up. I'm trying to sell this house and need the walls to STAY dry. Any help is appreciated!