01 / PRICE REFERENCES
How much does basement waterproofing cost?
The recorded interior drain and sump system reference is $40–$85 per ft, or $4,000–$8,500 for 100 ft. Method, access, water entry and restoration change the scope.
Interior drainage manages water inside the basement; exterior work requires access to the buried wall. An exterior drain reference alone does not price membrane installation. These are national planning references as of Oct 24, 2026, not local contractor quotes.
| Work | Planning range |
|---|---|
| Interior drain tile / sump system | $40–$85 / ft |
| Exterior foundation drain only | $30–$90 / ft |
| Minor crack injection | $250–$800+ / minor crack |
| Sump pump installation | $600–$2,500 / installation |
02 / INCLUDED WORK
What should an offer include?
Ask for measured length, the proposed system and discharge route. Compare demolition, drain installation, sump provision, concrete reinstatement and testing line by line.
Crack injection applies to minor cracks; structural repair is a separate assessment. A dehumidifier controls humidity and does not replace a drainage system.
03 / PRICE FACTORS
Six things that affect the cost.
Depth and foundation
Deeper foundations and different wall materials change access and the work required. The calculator records depth without inventing a price multiplier.
Access for excavation
Narrow side yards, utilities and nearby buildings may restrict equipment and require a separate excavation allowance.
Soil, rock and groundwater
Rock, saturated ground and discharge restrictions need an on-site assessment. A map cannot confirm these conditions.
Where water enters
A leaking wall-floor joint, a minor crack and a window well require different scopes. Diagnose the entry point before comparing methods.
Finished rooms
Removing and replacing flooring, drywall or built-ins can add work beyond the drain installation reference.
Restoration and permits
Confirm concrete replacement, landscaping, permits, disposal and discharge routing in each written offer.
04 / COMPARE THE SAME WORK
Compare the scope, not just the total.
- Ask which water entry points the system addresses.
- Use the same measured wall length in every offer.
- Check whether the sump, discharge and backup are included.
- Confirm restoration, permits, exclusions and warranty terms.
- Ask who will inspect and test the completed system.
05 / COMMON QUESTIONS
Questions about waterproofing prices.
Is waterproofing priced per ft or per ft²?
Drain systems use the selected wall length in ft. Membrane and surface treatments may use wall area in ft². Basement floor area is not a substitute for wall area.
Is the sump pump included?
The interior drain reference typically includes a sump. Do not add a separate pump installation to that package unless the contractor identifies additional work.
Can I seal a leaking wall myself?
Surface sealant does not resolve every source of water or structural movement. Ask a qualified professional to identify the cause before choosing a repair.
Is this a contractor quote?
No. These are published planning references recorded 24 October 2026. A local professional confirms scope and a fixed price after inspection.
06 / LOCAL PLANNING
Price and planning in your area.
Sources and calculation basis.
HomeGuide component references, recorded 24 October 2026. Published ranges describe particular work; they are not verified local offers. The worked example uses the same interior-drain rates as the calculator.