A1 Waterproofing is built on a simple promise: we fix it once, and we fix it right. From interior and exterior waterproofing to complete foundation repair, our team brings the skill and discipline to stop leaks and restore strength to your home. Backed by proven systems and a no-shortcuts approach, we deliver permanent solutions homeowners can count on. A1 Waterproofing is built on a simple promise: we fix it once, and we fix it right. From interior and exterior waterproofing to complete foundation repair, our team delivers permanent solutions homeowners can count on.