We live in a concrete coated red block building that has 12" thick walls. It was originally built for cold storage hence the thick walls. We are in the process of renovation and would like to seal the walls to keep moisture to a minimum. The current roof has no overhang and there was never any sealing done to the smooth morter stucco that was applied to the exterior. I am thinking of sealing the mortared walls to help keep the moisture out of the interior until we are ready to re stucco the exterior. My question is whether a quick sealing job now will interfere with future painting or possibly a shotcrete type mortar finish in the future. I would like to avoid having to sandblast the building before applying the new surface finish. I don't think we will get to it for a few more years however. Suggestions please. Moisture seaps through the walls wherever there is prolonged moisture on the exterior. The building is 5000 sq ft so we would like a simple method if possible.