Saint Louis, MO
Basement waterproofing and foundation repair costs in Saint Louis
Local cost ranges and contractors for every job that keeps water out ofa Saint Louis home, with the soil, water-table, freeze-thaw, and permit data specific to Saint Louis, MO, not a national average.
What each job costs in Saint Louis, MO
Modeled ranges for the five most common basement and foundation jobs in Saint Louis. Pick a job below for its permit notes, guides, and free quotes.
| Service in Saint Louis | Low | Average | High |
|---|---|---|---|
| Basement Waterproofing | $2,100 | $4,450 | $6,800 |
| Foundation Repair | $2,050 | $4,800 | $7,550 |
| Crawl Space Encapsulation | $2,750 | $5,100 | $7,450 |
| French Drain Installation | $1,400 | $3,500 | $5,600 |
| Sump Pump Installation | $600 | $1,350 | $2,050 |
These ranges are estimates modeled from regional Missouri pricing, not quotes from local projects. What you pay depends on square footage, access, and how severe the problem is, so treat this as a starting point and compare real quotes.
Costs & FAQ by service in Saint Louis
Basement Waterproofing in Saint Louis
Average basement waterproofing · avg $4,450
Interior and exterior systems that stop water seepage through foundation walls and floors.
How much does basement waterproofing cost in Saint Louis?+
In Saint Louis, basement waterproofing typically runs $2,100–$6,800, averaging about $4,450. That range is an estimate modeled from regional Missouri pricing rather than local project data, and the size of the job, access to the foundation, and how far the damage has progressed matter more than any regional average.
Do I need a permit for basement waterproofing in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Is basement waterproofing worth it in Saint Louis?+
With 52.8" of annual rainfall and about 67 freeze-thaw cycles a year, untreated water intrusion in Saint Louis tends to worsen each season, so most homeowners find addressing it early is far cheaper than structural repair later.
- Typical timeline
- 1–3 days
- Water table rises to
- ~2.2 ft · above basement floor
- Permit
- Usually required
- Local soil
- Darwin (slow-draining)
- Slow-draining ground
- 10 / 10 sampled points
- Freeze-thaw cycles
- 67 / yr
- Local pros
- 12 available
Foundation Repair in Saint Louis
Average foundation repair · avg $4,800
Fixing cracks, bowing walls, and settlement with piers, anchors, and structural reinforcement.
How much does foundation repair cost in Saint Louis?+
In Saint Louis, foundation repair typically runs $2,050–$7,550, averaging about $4,800. That range is an estimate modeled from regional Missouri pricing rather than local project data, and the size of the job, access to the foundation, and how far the damage has progressed matter more than any regional average.
Do I need a permit for foundation repair in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Is foundation repair worth it in Saint Louis?+
With 52.8" of annual rainfall and about 67 freeze-thaw cycles a year, untreated water intrusion in Saint Louis tends to worsen each season, so most homeowners find addressing it early is far cheaper than structural repair later.
- Typical timeline
- 2–5 days
- Water table rises to
- ~2.2 ft · above basement floor
- Permit
- Usually required
- Local soil
- Darwin (slow-draining)
- Slow-draining ground
- 10 / 10 sampled points
- Freeze-thaw cycles
- 67 / yr
- Local pros
- 12 available
Crawl Space Encapsulation in Saint Louis
Average crawl space encapsulation · avg $5,100
Sealing and vapor-barriering a crawl space to control moisture, mold, and wood rot.
How much does crawl space encapsulation cost in Saint Louis?+
In Saint Louis, crawl space encapsulation typically runs $2,750–$7,450, averaging about $5,100. That range is an estimate modeled from regional Missouri pricing rather than local project data, and the size of the job, access to the foundation, and how far the damage has progressed matter more than any regional average.
Do I need a permit for crawl space encapsulation in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Is crawl space encapsulation worth it in Saint Louis?+
With 52.8" of annual rainfall and about 67 freeze-thaw cycles a year, untreated water intrusion in Saint Louis tends to worsen each season, so most homeowners find addressing it early is far cheaper than structural repair later.
- Typical timeline
- 1–2 days
- Water table rises to
- ~2.2 ft · above basement floor
- Permit
- Usually required
- Local soil
- Darwin (slow-draining)
- Slow-draining ground
- 10 / 10 sampled points
- Freeze-thaw cycles
- 67 / yr
- Local pros
- 2 available
French Drain Installation in Saint Louis
Average french drain installation · avg $3,500
Perimeter drainage that channels groundwater away from the foundation before it gets in.
How much does french drain installation cost in Saint Louis?+
In Saint Louis, french drain installation typically runs $1,400–$5,600, averaging about $3,500. That range is an estimate modeled from regional Missouri pricing rather than local project data, and the size of the job, access to the foundation, and how far the damage has progressed matter more than any regional average.
Do I need a permit for french drain installation in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Is french drain installation worth it in Saint Louis?+
With 52.8" of annual rainfall and about 67 freeze-thaw cycles a year, untreated water intrusion in Saint Louis tends to worsen each season, so most homeowners find addressing it early is far cheaper than structural repair later.
- Typical timeline
- 1–2 days
- Water table rises to
- ~2.2 ft · above basement floor
- Permit
- Usually required
- Local soil
- Darwin (slow-draining)
- Slow-draining ground
- 10 / 10 sampled points
- Freeze-thaw cycles
- 67 / yr
- Local pros
- 3 available
Sump Pump Installation in Saint Louis
Average sump pump installation · avg $1,350
Pump systems that evacuate collected water from a basement or crawl space pit.
How much does sump pump installation cost in Saint Louis?+
In Saint Louis, sump pump installation typically runs $600–$2,050, averaging about $1,350. That range is an estimate modeled from regional Missouri pricing rather than local project data, and the size of the job, access to the foundation, and how far the damage has progressed matter more than any regional average.
Do I need a permit for sump pump installation in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Is sump pump installation worth it in Saint Louis?+
With 52.8" of annual rainfall and about 67 freeze-thaw cycles a year, untreated water intrusion in Saint Louis tends to worsen each season, so most homeowners find addressing it early is far cheaper than structural repair later.
- Typical timeline
- Under 1 day
- Water table rises to
- ~2.2 ft · above basement floor
- Permit
- Usually required
- Local soil
- Darwin (slow-draining)
- Slow-draining ground
- 10 / 10 sampled points
- Freeze-thaw cycles
- 67 / yr
- Local pros
- 12 available
What affects the cost in Saint Louis
Climate: ERA5 reanalysis via Open-Meteo
USDA soil maps put Darwin soils across much of Saint Louis, and 10 of the 10 rated sample points fall in hydrologic groups that shed water slowly. Ground like that pushes rain and snowmelt sideways against foundation walls instead of letting it soak away, and roughly 67 freeze-thaw cycles a year work at any crack that lets it in. Soil varies sharply across Saint Louis, so treat this as the pattern across 17 sampled points rather than a description of your lot.
Soil: USDA NRCS SSURGO · Darwin-Aquents-Urban land complex, 0 to 2 percent slopes, occasionally flooded, long duration · 17 points sampled
Permits in Saint Louis
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits.
In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Issuing authority: Building Division (Department of Public Safety, City of St. Louis) · Official fee schedule · Verified 2026-07-16
See how Saint Louis compares: permit fees in 118 US cities →
39% of basement flood claims in St. Louis city were filed outside the flood zone →
What puts water in a Saint Louis basement
The ground under Saint Louis holds water close to the surface: in a typical year the seasonal-high water table modeled from USDA soil survey rises to within about 2.2 ft of grade, shallower than the roughly 7 ft depth of a full basement floor. Where groundwater stands above the floor it presses on the slab and the wall-floor joint, the hydrostatic pressure that drives water through basement concrete.
The soil compounds it: 10 of 10 sampled points are slow-draining ground that holds water rather than shedding it.
And it is not only a floodplain problem: in St. Louis city, about 39% of basement flood-insurance claims were filed outside the mapped flood zone, and because flood insurance is mostly bought only inside that zone, the real outside-the-zone share is almost certainly higher.
Sources: climate ERA5 reanalysis via Open-Meteo; soil and water table USDA NRCS SSURGO, 17 points sampled. Water-table figures are modeled seasonal highs, not a reading of one lot.
In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
Issuing authority: Building Division (Department of Public Safety, City of St. Louis) · Verified 2026-07-16
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Saint Louisbasement & foundation FAQ
Why do basements take on water in Saint Louis?+
The main driver in Saint Louis is groundwater. The seasonal-high water table (modeled from USDA soil survey) rises to about 2.2 ft below grade, shallower than a typical 7 ft basement floor, so at its peak it presses up against the slab and in at the wall-floor joint. Roughly 67 freeze-thaw cycles a year add frost pressure on top of that.
How much does basement waterproofing cost in Saint Louis?+
As a planning range, basement waterproofing in Saint Louis runs about $2,100–$6,800. That figure is modeled from regional Missouri pricing, not a survey of local jobs, and what you actually pay depends on the method, the size of the basement, and how the water is getting in. Compare real quotes.
Do I need a permit for foundation or waterproofing work in Saint Louis?+
The Building Division lists foundation and footing repair or replacement, underpinning, and shoring of a structure as work requiring a residential building permit in the City of St. Louis. Foundation repair and waterproofing jobs are charged under the same valuation-based fee schedule as other building permits. Permits are issued by Building Division (Department of Public Safety, City of St. Louis). In the City of St. Louis, a building permit costs a flat $25 non-refundable application fee due at submission, plus a permit fee based on estimated construction cost that is due after approval and before the permit is issued. That permit fee is $19 for jobs valued at $0 to $1,000, $23 for $1,001 to $2,000, $30 for $2,001 to $3,000, and for anything over $3,000 it is $10 per $1,000 of estimated construction cost or fraction thereof. A $6,000 foundation repair would run about $60 in permit fee plus the $25 application fee, roughly $85 total before any other trade permits.
My home isn't in a flood zone, can the basement still flood in Saint Louis?+
Yes. In St. Louis city, about 39% of basement flood-insurance claims were filed outside the mapped flood zone, and because flood insurance is mostly bought only inside the zone, the true out-of-zone share is almost certainly higher. Basement water is usually a groundwater problem, which the flood map does not measure.