Basement waterproofing cost
Waterproofing a basement averages about $5,000 nationally, and most homeowners pay between $3,000 and $10,000, or roughly $3 to $10 per square foot.
| Fix | Where | Typical cost |
|---|---|---|
| Waterproof paint or sealant | Inside | $1 to $8 per sq ft |
| Epoxy crack injection | Inside | $250 to $1,000 per crack |
| Interior perimeter drain | Inside | $40 to $120 per linear ft |
| Sump pump | Inside | $600 to $2,500 |
| Vapor barrier | Inside | $1,500 to $4,000 |
| Dehumidifier | Inside | $1,000 to $2,800 |
| Soil regrading | Outside | $500 to $3,000 |
| Gutters and downspouts | Outside | $3 to $30 per linear ft |
Start with the cheap fixes
A lot of basement water starts outside: clogged gutters, downspouts dumping next to the wall, or soil that slopes toward the house. Fix those first. If water still comes in through cracks or where the wall meets the floor, that's when an interior drain and sump pump make sense.
Inside methods cost less but manage water that's already getting in. Exterior waterproofing stops it at the wall but costs more because of the digging.
Sources
Last checked November 3, 2026.