Foundation & Basement
Waterproofing

Signs that waterproofing is needed: visible water seeping through walls or floor, white mineral deposits (efflorescence) on concrete, chronic musty smell, mold growth, or visible cracks with water staining. Surface drainage improvements alone can help with minor issues — active water intrusion through the foundation requires proper waterproofing.

Interior drain system installation typically runs $5,000–$15,000 depending on perimeter length and sump pump requirements. Exterior waterproofing is more expensive — $10,000–$30,000+ — because of excavation. Crack injection repairs are usually $500–$2,000 per crack. We provide a detailed estimate after diagnosing the actual source of the problem.

Exterior waterproofing addresses the problem at the source — a membrane is applied to the outside of the foundation before water can enter. Interior waterproofing manages water that has already entered by capturing it in a drain channel and routing it to a sump pump. Interior systems are less disruptive and less expensive, and are effective for most situations.

Interior drain system installation typically takes 1–3 days depending on perimeter length. Exterior waterproofing requires 3–5+ days due to excavation, application, and backfill. Crack injection is usually completed in a single day.

Waterproofing eliminates the moisture that feeds mold — but existing mold must be properly remediated separately. Once the moisture source is addressed, we recommend professional testing and remediation before finishing the space. We can refer qualified remediation contractors in the Greater Boston area.

Interior drain systems require minimal maintenance — mainly checking that the sump pump is functioning and testing the battery backup annually. We walk you through the full maintenance checklist before we leave the job site.