An interior basement French drain typically costs $4,000–$17,000, or about $40–$100 per linear foot, including cutting and replacing the concrete floor and a sump pump. A 100-ft basement perimeter with one pump runs about $4,000–$8,500 (HomeGuide, Angi and LawnStarter data, as of October 2026).
Updated October 8, 2026. Source: HomeGuide + 4 more. National US estimates.
An interior basement French drain (also called interior drain tile or a perimeter drain) runs along the inside of the foundation walls, under the edge of the slab. It catches water seeping through the walls or where the wall meets the floor and carries it to a sump pit, where a pump sends it outside. It's one of the most common fixes for chronically wet basements.
Below you'll find typical prices by basement size, what's included, and the extras that often come with the job. For a full comparison of waterproofing methods, see our basement waterproofing cost guide.
Average cost
Typical interior basement French drain prices, national averages as of October 2026:
| Scenario | Typical range | Notes |
|---|---|---|
| Partial run along one or two walls (25–50 ft) | $1,000–$5,000 | Targets the wall where water enters |
| Small basement perimeter, about 100 ft, 1 sump pump | $4,000–$8,500 | Common for smaller homes |
| Mid-size basement, 150 ft, 2 sump pumps | $6,000–$12,800 | Most full-perimeter jobs land here |
| Large basement, 200 ft+, 2 sump pumps | $8,000–$20,000 | Longer runs, more concrete work |
Related basement waterproofing costs
| Item | Typical cost | Notes |
|---|---|---|
| Sump pump added to a drain system | $600–$2,500 | Pit, pump, check valve and discharge line |
| Waterproof sealant or paint on walls | $2–$10 per sq. ft. | Installed; helps with dampness, not leaks |
| Crack injection | $250–$800 per crack | Epoxy or polyurethane |
| Interior waterproofing package | $6,000–$12,000 | Drain, sump and wall treatment together |
| Full basement waterproofing | $6,000–$18,000 | Interior or exterior systems |
Cost breakdown: materials, labor, permits and extras
Line-item estimate for installing about 150 ft of interior perimeter drain in a basement with one new sump pump. Ranges are national, as of October 8, 2026.
| Cost item | Typical range | What it covers |
|---|---|---|
| Labor and concrete work | $3,500–$8,000 | Cutting the slab edge, breaking and hauling concrete, trenching, repouring |
| Drain pipe, gravel and wall flange | $800–$2,000 | Perforated pipe, washed stone, edge membrane to direct wall seepage |
| Sump pit and pump | $600–$2,000 | Liner, pump, check valve and discharge to the exterior |
| Permits | $0–$375 | Required in some towns for plumbing or discharge work |
| Contingency (about 10%) | $300–$900 | Extra wall cracks, utility lines in the floor |
| Estimated total | $5,200–$13,500 | Before any discounts or rebates |
Per-foot quotes from waterproofing companies usually bundle the concrete removal and repour; ask for it to be confirmed in writing.
What affects the price
- Linear feet of drain. Price scales with the length of the perimeter: about $40–$85 per linear foot (HomeGuide) and up to $100 in Angi and LawnStarter data. A 100-ft basement costs about $4,000–$8,500, while 200 ft runs about $8,000–$17,000.
- Cutting and removing the concrete floor. Breaking out a strip of slab along the walls, hauling away the concrete and repouring it is the main reason interior drains cost several times more than yard drains. Thicker slabs, rebar or tight access raise the price.
- Sump pit and pump. Most systems end in a sump pit with a pump. Adding a sump pump to the system costs about $600–$2,500, and larger basements often get two pumps.
- Wall sealing. Many contractors add a plastic edge membrane or dimple board at the wall base to guide seepage into the drain. Sealing the walls themselves with waterproof coatings runs about $2–$10 per sq. ft., and crack injection $250–$800 per crack.
- Floor restoration. Bids usually include a basic concrete patch over the trench. Finished basements cost more because flooring, drywall, trim and built-ins along the walls must be removed and replaced.
Ways to save
- Fix gutters, downspouts and grading first; if water stops entering, you may need only a partial drain or none at all.
- If water enters along only one or two walls, ask about a partial run instead of a full perimeter.
- Clear and remove finishes near the walls yourself before the crew arrives, if the contractor allows it.
- Get at least three written quotes, and compare length, number of pumps, battery backup, wall membrane and warranty transferability.
- Beware of high-pressure sales: compare a basement waterproofing company's package price with the per-foot rates in this guide.
How to get an accurate quote
Ask at least three licensed, insured basement waterproofing contractors for written, itemized quotes. Give each the same information:
- The basement's perimeter in feet, ceiling height and whether it is finished.
- Where and when water comes in (wall cracks, the floor joint, window wells) and photos after heavy rain.
- Whether you already have a sump pit or pump and where water can be discharged outside.
- Ask what is included: concrete removal and repour, pipe type, wall membrane, number and type of pumps, battery backup, permits and warranty.
FAQ
Is an interior French drain better than an exterior one?
Interior drains are usually cheaper than excavating around the whole foundation and can be installed year-round, but they manage water after it reaches the wall rather than keeping it off. Exterior perimeter drains cost about $30–$90 per linear foot plus excavation and landscaping.
How long does it take to install a basement French drain?
Most residential basements take a few days: cutting and removing concrete, trenching, installing pipe and the sump, then repouring the floor. The new concrete needs time to cure before you refinish the area.
Do I need a sump pump with a basement French drain?
Almost always. Interior drains sit below the level where water can drain by gravity, so they empty into a sump pit and a pump discharges the water outside.
For the big picture, start with our complete french drain cost guide.
Related cost guides
Sources
- HomeGuide — How Much Does a French Drain Cost? (2026) (Feb 5, 2026). Checked October 8, 2026.
- HomeGuide — How Much Does a Drainage System Cost? (2026) (Feb 6, 2026). Checked October 8, 2026.
- HomeGuide — How Much Does Basement Waterproofing Cost? (2026) (Jan 23, 2026). Checked October 8, 2026.
- Angi — How Much Does a French Drain Cost? [2026 Data] (updated May 30, 2026). Checked October 8, 2026.
- LawnStarter — How Much Does a French Drain Cost in 2026? (updated Oct 5, 2026). Checked October 8, 2026.
Prices are estimates and vary by location and provider. See our methodology and editorial policy. Browse all foundation & water cost guides.