Basement Waterproofing Cost (2026): Interior Drain Tile per Foot, Exterior, Sumps and Cracks, With Labor Hours
What basement waterproofing costs a contractor in 2026: interior drain tile by the foot, sumps and backups, exterior excavation by depth, crack injection, bowing walls and crawlspace encapsulation, with the code and labor hours.
The assumptions
This model assumes
- A poured basement, 8 ft walls, 140 ft of perimeter unless stated
- Permits only where Clamp carries one (wall bracing)
- Job cost before markup: labor and materials, no markup or tax
- Prices from Clamp's catalog on November 5, 2026
The model, step by step
Priced through Clamp's catalog on November 5, 2026, with labor hours. Every price in this guide is job cost before markup: what the labor and materials cost you, before your overhead and profit. The ballpark price ranges add a typical markup to that. Interior jobs include protection and dust control, the slab cut and patch, pipe and stone, the sump and discharge, and haul-off. Exterior jobs include the dig, membrane, footing drain, backfill and surface restoration.
The basement
Drawn for this guide in the style of Quick Clamp's sketch pad: a 30 x 40 basement with 140 ft of perimeter drain, a sump in the corner and two cracks to inject. Demo data.
| Job | Job cost | Hours |
|---|---|---|
| Interior drain, 140 ftNew sump and pump, 20 ft discharge | $11,200 | 76 |
| Same, wall membraneDimple membrane to the drain | $12,950 | 76 |
| Same, existing sumpDrain only, no wall membrane | $9,115 | 60 |
| Interior drain, 60 ftTwo walls, new sump | $6,195 | 44 |
| Exterior, 40 ft at 7 ftOne wall dug out | $5,996 | 37 |
| Exterior, 140 ft at 6 ftMembrane, footing drain | $19,369 | 112 |
| Exterior, 140 ft at 7 ftMembrane, footing drain | $21,150 | 130 |
| Exterior, 140 ft at 8 ftMembrane, footing drain | $23,156 | 149 |
Interior drain tile is priced by the foot of perimeter. In Clamp's catalog the drain itself (cut, trench, pipe, stone, patch, haul-off) runs about $65 a foot on 140 ft, and the whole job with a new sump about $80 a foot. A wall membrane that sheds wall seepage into the drain adds about $13 a foot.
Interior and exterior
Drawn for this guide in the style of Quick Clamp's sketch pad: an interior drain with a wall membrane against an exterior dig with membrane, drainage board and footing drain. Demo data.
Published prices a foot (customer)
Fixr (February 2026)$40 to $120 a foot for an interior perimeter drain.
A sump is its own scope when the drain is already there, and part of every new interior system.
| Job | Job cost | Hours |
|---|---|---|
| New pit and primary pumpPrimary pump, 15 ft discharge | $2,003 | 16 |
| New pit, pump and battery backupSecond pump and battery | $2,978 | 18 |
| New pit, pump and water backupWater-powered backup | $2,753 | 18 |
| Replace the pumpExisting pit | $1,053 | 4 |
Where the water goes
DischargeWentzville, Missouri wants discharge at grade and at least 5 ft from the property line.
Sanitary sewerElyria, Ohio bans sump and footing drain discharge into the sanitary sewer.
EquipmentA Zoeller M53, a 3/10 hp pump, lists at $617.99 at Zoro.
Exterior waterproofing stops the water at the wall instead of managing it inside. Clamp prices the dig and backfill by the cubic yard, the membrane by the square foot of wall, and the footing drain and restoration by the foot, so depth moves the price: about 9% a foot of depth on 140 ft.
| Depth | Job cost | Hours |
|---|---|---|
| 6 ft$138 a foot | $19,369 | 112 |
| 7 ft$151 a foot | $21,150 | 130 |
| 8 ft$165 a foot | $23,156 | 149 |
When exterior is the call
New construction or a full digCode dampproofing or waterproofing goes on the outside of the wall.
Finished basementDigging outside keeps the finishes inside.
One bad wallA 40 ft wall at 7 ft is $5,996; price the wall, not the house.
Polyurethane seals a leaking crack and flexes with it; epoxy bonds a crack that needs its strength back. A bowing or displaced wall is a structural repair: Clamp carries an engineer's review and a permit with every bracing job.
| Repair | Job cost | Hours |
|---|---|---|
| One crack, polyurethane8 ft, leaking | $935 | 5 |
| Two cracks, polyurethane16 ft | $1,375 | 5 |
| One crack, epoxy8 ft, structural bond | $1,067 | 5 |
| 5 carbon fiber strapsEngineer and permit | $4,845 | 5 |
| 5 steel wall bracesEngineer and permit | $6,345 | 5 |
| 5 wall anchorsEngineer and permit | $6,220 | 5 |
Drainage handles water; coatings and membranes keep a wall from wetting. Price the one the problem needs.
The code
Grading (R401.3)The ground falls at least 6 in. within the first 10 ft from the foundation. Check grading, gutters and downspouts first.
Drains (R405.1)Foundations that retain earth get drains, except on well-drained soils.
Dampproofing or waterproofing (R406)Dampproofing is the default; waterproofing where a high water table or severe soil-water conditions are known.
Local rulesLucas County, Ohio requires waterproofing on 1- to 3-family homes with below-grade living or usable space.
Coatings
Joe Lstiburek, Building Science CorporationOn a leaking wall, coatings don't work; drain the water to a sump with an airtight lid.
Rated coatingsDRYLOK Extreme is rated to 15 psi on properly prepared masonry; it doesn't replace drainage on an active leak.
Clamp prices a 1,000 sq ft crawlspace sealed with a liner up the walls, vents closed, a dehumidifier and its circuit at $6,499 job cost before markup, about 38 person-hours.
The rules
R408.3An unvented crawlspace needs a Class I vapor retarder lapped 6 in., sealed and run 6 in. up the wall, plus one of four options: exhaust, conditioned supply air, a plenum, or a dehumidifier.
Dehumidifier sizeThe model code sizes it to the maker's specifications.
PayoffA DOE Building America case study (September 2015) says sealed crawlspaces can cut space-conditioning energy 15% to 18% compared to vented ones.
A 30 x 40 ft poured basement (140 ft of perimeter) takes water at the cove joint after heavy rain, through two vertical cracks, with no sump. Inside: drain tile on the full perimeter, a dimple membrane on the walls, a new sump with a primary pump and a battery backup, 30 ft of discharge, and the two cracks injected with polyurethane: $15,420 job cost before markup, 82 person-hours. Outside, dug to 7 ft with membrane, footing drain and the cracks sealed: $22,030.
| Line | Job cost | Hours |
|---|---|---|
| Cut, trench and lay the drain140 lf | $6,300 | 56.0 |
| Wall drainage membrane140 lf | $1,750 | |
| Stone, fabric and slab patch140 lf | $1,470 | |
| Dig and set the sump pit1 ea | $950 | 12.0 |
| Inject two cracks16 lf | $880 | |
| Battery backup pump1 ea | $600 | |
| Perforated pipe and fittings140 lf | $595 | |
| Set the primary pump1 ea | $525 | 4.0 |
| 30 ft discharge line30 lf | $495 | |
| Haul-off2 ea | $450 | |
| Injection setup1 ea | $450 | 4.5 |
| Set the backup pump1 ea | $375 | 2.0 |
| Protection and dust control1 ea | $300 | 3.5 |
| Primary pump1 ea | $280 |
The job
Every line priced
The job in Clamp, and the estimate it prices: $15,420 at job cost, by trade. Illustration of the Clamp app.
What it means
Every basement, line by line
Clamp reads the perimeter, interior or exterior, the membrane, the sump and backup, the discharge run and the cracks from the words, and prices each line with labor hours.
Waterproofing is priced by the foot of wall; the sump, membrane and cracks decide the rest.
Questions
How much does basement waterproofing cost?
In Clamp's catalog, interior drain tile on a 140 ft basement perimeter with a new sump is $11,200 in job cost before markup, $12,950 with a wall membrane. Exterior excavation and membrane on the same 140 ft at 7 ft deep is $21,150. Ballpark price ranges: $14,560 to $22,400 interior, $27,495 to $42,300 exterior.
How much does interior drain tile cost per linear foot?
About $80 a foot in job cost before markup with a new sump, on 140 ft in Clamp's catalog. Fixr (updated February 2026) lists $40 to $120 a foot for an interior perimeter drain.
How much does exterior basement waterproofing cost?
Clamp's catalog prices 140 ft of wall at $19,369 dug to 6 ft, $21,150 at 7 ft and $23,156 at 8 ft in job cost before markup, with membrane, footing drain, backfill and restoration. One 40 ft wall at 7 ft is $5,996.
How much does crack injection cost?
One 8 ft leaking crack injected with polyurethane is $935 in job cost before markup in Clamp's catalog, $1,067 with epoxy. Fixr lists $250 to $1,000 a crack for epoxy injection.
How much should a contractor charge for basement waterproofing?
Price the job cost by the foot of perimeter, then the sump, membrane and cracks, then add your markup. The 140 ft interior example with membrane, battery backup and two cracks is $15,420 job cost before markup, a ballpark price range of $20,046 to $30,840.
Sources & provenance
- Clamp's catalog, priced by script Clamp (research)
- 2021 International Residential Code, Chapter 4: Foundations International Code Council (official source)
- Waterproofing Lucas County, Ohio (official source)
- Interior foundation and basement retrofits Dörken DELTA Academy (Joe Lstiburek) (research)
- Building America case study: sealed crawlspaces US Department of Energy (official source)
- Basement waterproofing cost Fixr (research)
- Basement waterproofing cost This Old House (research)
- DRYLOK Extreme masonry waterproofer DRYLOK (research)
- Zoeller M53 Mighty-Mate Zoro (research)
- Sump pump guide City of Wentzville, Missouri (official source)
- Waterproofing permit City of Elyria, Ohio (official source)
- How much does crawl space encapsulation cost? Angi (research)
- How much does basement waterproofing cost? Angi (research)