Cost Guide · 2026
How much basement waterproofing costs
Every number below is a published third-party figure with the publisher named and the date it was retrieved. We do not model, adjust or regionalise them, because a precise-sounding local number nobody can trace is the exact problem this site exists to push against.
The short answer
Most homeowners pay between $2,461 and $8,201. The average job is about $5,240. Simple crack sealing can come in near $1,000; a full exterior excavation with French drains and membrane can pass $20,000.
Sources: Angi, This Old House — both retrieved 2026-08-30.
Three published ranges, and why they disagree
These publishers are not contradicting each other. They are measuring different things — a typical job, a per-square-foot rate, and the heavier end of the market. Averaging them together would destroy the only useful information they carry.
Typical whole-job range
$2,461–$8,201total
Most homeowners fall in this band; the average sits at about $5,240.
Angi, retrieved 2026-08-30By basement size
$3–$10per sq ft
A 1,000 sq ft basement therefore lands between about $3,000 and $10,000.
HomeGuide, retrieved 2026-08-30Larger / severe-problem jobs
$6,000–$18,000total
Where the method is heavier and the water problem is worse.
This Old House, retrieved 2026-08-30Cost by method
This is the table to hold your quote against. If a bid does not say which of these it is, that is the first question to ask — not the price.
| Method | Published range | Source |
|---|---|---|
| Sealants & crack repair | $600–$1,500 | This Old House |
| Interior drainage system | $3,000–$8,000 | Fixr |
| Interior French drain | $4,000–$17,000 | HomeGuide |
| Exterior excavation & membrane | $8,000–$15,000 | This Old House |
| Exterior French drain | $30–$90/ft | HomeGuide |
Labour is published at about $200 per hour (HomeGuide), which is why the size of the crew and the number of days matter as much as the method itself.
What this page does not have yet
We do not publish a city-by-city price, because we do not have verified city-by-city data — and neither does anyone else publishing one. Regional waterproofing prices are not collected anywhere public. Any site showing you a confident number for your specific metro has almost certainly interpolated it from a national average.
We are building the real version from actual quotes homeowners send us through the Quote Autopsy. When a metro has enough real quotes to say something true, that metro gets a page — and it will be labelled as our data, with the sample size shown.