Planning foundation or waterproofing work? Find contractors by state, county or city. Our guides cover general planning; check the directory for current local coverage.
Short answer
Before comparing waterproofing quotes, establish where and when water gets in. Ask each contractor to explain the entry points and to price the specific approach (yard drainage, exterior membrane, interior drain and sump, crack injection, or a combination). Compare what each option manages, what maintenance it needs and what the warranty covers.
Find where the water comes from
Note when water appears (after heavy rain, snowmelt or all year), and where: through cracks, at the joint between wall and floor, through window wells or up through the floor. Gutters, downspouts and grading that slopes toward the house are common contributors and are often cheaper to fix first. Ask each contractor what they think is happening and why.
Interior and exterior systems do different jobs
Exterior waterproofing applies a membrane and drainage to the outside of the wall, which usually means excavation. Interior systems collect water that reaches the wall or floor and route it to a sump pump. Ask what each option stops versus manages, what it disturbs and what it needs over time, such as pump testing and a backup power plan.
Sump pumps and discharge
If a sump pump is proposed, ask about pump capacity, a backup option, alarm, and where the discharge goes. Local rules may restrict discharging into sanitary sewers or onto neighboring property; ask who checks this.
What a basement drainage and waterproofing quote should include
- Diagnosed entry points
- Gutter, downspout and grading recommendations
- System proposed: interior drain, sump, exterior membrane, crack injection
- Excavation and restoration
- Sump capacity, backup and discharge location
- Maintenance needs and warranty terms
Find basement drainage and waterproofing contractors near you
Browse the location directory by state, county or city. Each listing shows its license record and the dated source showing the business offers the service. Check the license in the state lookup before hiring, and ask for examples of comparable work.
Ready to describe the problem? Request quotes for basement drainage and waterproofing.
Find the right contractor for the problem
What to ask, and what the written quote should include, for each type of work.
- Piering and underpinningWhat to compare before you hire
- Bowing wall repairWhat to compare before you hire
- Slab foundation repairWhat to compare before you hire
- Crawl space repairWhat to compare before you hire
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Frequently asked questions
Is interior or exterior waterproofing better?
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It depends on where water enters, site access and budget. Ask each contractor to explain why they recommend one approach for your basement and what it would not solve.
Sources
- [1]Federal Trade Commission, Consumer Advice, Hiring a Contractor (added October 16, 2026; not yet re-checked)
Any prices are ranges published by the sources above, not quotes. Your price depends on the diagnosis, access, soil, permits and local labor rates. Compare written quotes for the same scope.