How much does basement waterproofing cost?
Basement waterproofing typically costs $3,000 to $10,000, and homeowners spend around $5,000 on average, according to Fixr.com. This Old House puts interior methods (drains, sump pumps and coatings) at $2,000 to $6,000 and exterior waterproofing, which means digging down to the outside of the foundation, at $7,000 to $15,000.
What are the types of basement waterproofing?
- Interior drainage. A channel is cut into the basement floor along the walls, a perforated pipe is laid in gravel, and the water runs to a sump pump that pumps it outside. It manages water that gets in rather than stopping it at the wall.
- Exterior waterproofing. The soil is dug away from the outside of the foundation, a membrane or coating is applied to the wall, and a drain is usually laid at the footing. It stops water before it reaches the wall, and is the most disruptive option.
- Crack injection. Individual leaking cracks in poured concrete walls are filled. Useful when the leak is one or two cracks.
- Sealers and coatings. Paint-on products for minor dampness. They do not stop water under pressure.
How much does each type cost?
| Method | Typical cost | Source |
|---|---|---|
| Interior methods (drain, sump pump, coatings) | $2,000–$6,000 | This Old House |
| Interior perimeter drain | $40–$120 per linear foot | Fixr.com |
| Exterior waterproofing | $7,000–$15,000 | This Old House |
| Epoxy crack injection (per crack) | $250–$1,000 (Fixr.com); $800–$1,500 (This Old House) | Fixr.com; This Old House |
| Waterproof paint or sealant | $1–$8 per sq ft | Fixr.com |
| Sump pump, installed | $600–$2,500 | Fixr.com |
Is interior or exterior waterproofing better?
Exterior waterproofing keeps water off the wall, so it also protects the wall itself, but it means digging around the house, removing landscaping, and often costs much more. Interior drainage is less disruptive and more common for finished neighborhoods, but it lets water reach the wall and depends on a working sump pump. Many contractors recommend interior systems because they are faster to install. Ask why they recommend one over the other for your house.
What makes basement waterproofing cost more or less?
- Length of wall being treated. Interior systems are often priced per linear foot.
- Finished basements. Drywall, flooring and built-ins have to come out and go back.
- Digging conditions for exterior work: depth, decks, driveways, landscaping.
- Sump pump choice and whether a battery backup is added.
- Wall problems. Cracked or bowing walls need structural repair, which is priced separately.
Can I fix a wet basement without waterproofing?
Sometimes. A lot of basement water comes from gutters that overflow, downspouts that drop water next to the foundation, or soil that slopes toward the house. Those fixes are far cheaper and are worth checking first. See wet basement: causes and fixes.
Common questions
How much does it cost to waterproof a basement?
Typically $3,000 to $10,000, with an average of around $5,000, according to Fixr.com. Interior systems usually cost less than exterior excavation.
How much does interior basement waterproofing cost?
Interior methods average $2,000 to $6,000, according to This Old House. Interior perimeter drains are often priced per linear foot of wall, at $40 to $120 per linear foot, according to Fixr.com.
Is basement waterproofing worth the money?
If water is getting in regularly, it protects the house and anything stored or finished in the basement. If the cause is gutters or grading, fix that first and see if the water stops.
Does homeowners insurance cover basement waterproofing?
Generally no. Insurance usually treats waterproofing as maintenance. Check your own policy, and ask your agent about sump pump backup coverage, which is often a separate add-on.
Sources
- Fixr.com, Basement Waterproofing Cost (page updated Feb 6, 2026) — fixr.com, checked Nov 3, 2026
- This Old House, Basement Waterproofing Cost (page updated Mar 4, 2026) — thisoldhouse.com, checked Nov 3, 2026
8 questions to ask any basement or foundation contractor
Ask these before you sign, whoever you hire.