Typical totals
| Work | Typical cost |
|---|---|
| Overall, per square foot of basement | $6–$15 per sq ft |
| Interior waterproofing, 750–1,000 sq ft basement | $4,500–$10,000 |
| Exterior waterproofing, 750–1,000 sq ft basement | $10,000–$15,000 |
| Sump pump replacement only | $400–$700 |
| Bowing wall repair, 20 linear ft | $1,600–$11,000 |
| Yard grading | $500–$3,000 |
Prices by item
| Item | Range |
|---|---|
| Interior drain tile (interior French drain) | $40–$85 per linear ft |
| Sump pump installed | $600–$2,500 per each |
| Battery backup sump pump | $150–$800 per each |
| Crack injection | $250–$800 per crack |
| Wall anchors or straps for bowing walls | $80–$280 per linear ft |
| Exterior French drain | $30–$90 per linear ft |
| Exterior waterproof membrane | $4–$7 per sq ft of wall |
| Whole-basement dehumidifier | $1,100–$2,800 per each |
Sources: HomeGuide: basement waterproofing cost; HomeGuide: sump pump installation cost; HomeGuide: foundation crack repair cost; HomeGuide: bowing basement wall repair cost.
What changes the price
- How many walls leak. Drain tile and exterior work are priced by the foot, so one bad wall costs far less than four.
- Inside or outside. Exterior work means excavating to the footing; interior work means breaking out the floor edge.
- Finished space. Drywall, framing and flooring along the walls have to come out for interior systems.
- Wall type and condition. Block walls, bowing walls and old stone foundations need more than a drain.
- Access. Decks, driveways and landscaping next to the wall make excavation harder.
Cheap fixes to try first
University of Minnesota Extension guidance traces much basement seepage to surface water. Before paying for a system, make sure gutters work, downspouts carry water well away from the house, and the ground falls at least 6 inches within 10 feet of the foundation (source). Yard grading itself typically costs $500–$3,000.
Common questions
How much does basement waterproofing cost in Green Bay?
National cost guides put interior waterproofing for a 750–1,000 sq ft basement at about $4,500–$10,000 and exterior waterproofing at $10,000–$15,000, or roughly $6–$15 per square foot overall. Single fixes cost less: a sump pump runs $600–$2,500 installed and crack injection $250–$800 per crack. Use the cost estimator for your basement, then compare local quotes.
Interior or exterior waterproofing: which is better?
Interior drain tile and a sump manage water that gets past the wall and is usually cheaper and less disruptive. Exterior waterproofing keeps water off the wall itself but means digging down to the footing. Many homes only need one; a contractor can tell from where and when the water appears.
Can gutters and grading fix it?
Often they help a lot. Extension guidance says much basement seepage comes from surface runoff: missing gutters, short downspouts and ground sloping toward the house. It recommends the ground fall at least 6 inches within 10 feet of the foundation. These are worth fixing before paying for drain tile.
Do I need to remove finished walls?
Interior drain tile and crack repair need access to the bottom of the walls and the floor edge, so some drywall and flooring usually comes out. Exterior work can leave the inside alone. Mention finished areas in your request so quotes include it.