We just waterproofed this foundation in Medina, WA before backfill. We use a PolyWall Pro 1000 sprayed product to keep unwanted moisture from breaching the foundation, and providing protection against mold and mildew. Patented, thermoplastic technology outperforms other waterproofing. Then on top of that we use a DELTA®-DRAIN mat system. The best money a contractor can ever spend are dollars to protect against any type of water intrusion.