Foundation Waterproofing & Air Barrier Systems

What Is Exterior Waterproofing and Where Is It Used?  Exterior foundation waterproofing is a proactive method of protecting a structure by preventing water from ever entering the building envelope. Unlike interior drainage solutions, which manage water after it’s already infiltrated the foundation, exterior waterproofing stops moisture at the source—outside.  This system is most commonly applied to basement walls, crawlspace foundations, and retaining walls. It involves excavating around the structure, cleaning and prepping the foundation, applying a waterproof membrane (sheet or liquid), and installing a drainage system like a footing drain or French drain. For added protection and insulation, foam board is often installed over the membrane before backfilling.  

Exterior waterproofing is ideal for both new construction and existing homes or commercial buildings.  For new builds, it’s an opportunity to install a full protection system before the structure is backfilled, ensuring long-term performance.  For existing structures, especially those experiencing signs of water intrusion (like damp walls, musty odors, or visible mold), retrofitting an exterior waterproofing system can be a permanent solution.   We use premium products like GCP Bituthene 3000, Henry Blueskin WP200, and liquid-applied waterproofing membranes, combined with drain boards and 2” foam to deliver comprehensive, code-compliant protection.  From full-perimeter basement waterproofing to targeted repairs on crawlspace walls, exterior waterproofing remains the gold standard in foundation protection.