Basement Waterproofing Cost Calculator for Seattle, WA
Thinking about an interior drain, a pump or a crack repair in a Seattle, WA basement? Answer four short questions and this page turns them into a rough dollar range built from published national rates. It asks for nothing personal, and the result is a planning figure to set beside a contractor's written estimate later.
Before You Start
The size you pick stands in for the length of foundation wall around the basement. The calculator keeps only the share you say needs a drain, prices those feet at the interior perimeter drain rate, and adds a sump pump and epoxy crack injection when your answers call for them. Those three rows, interior perimeter drain, sump pump installation and epoxy crack injection, come from Fixr's 2026 national table below.
| Cost row | Figure | Source (year) |
|---|---|---|
| Typical basement waterproofing project | about $3,000 to $10,000 (average about $5,000) | Fixr national (2026) |
| Interior perimeter drain, per linear foot | $40 to $120 | Fixr national (2026) |
| Sump pump installation | $600 to $2,500 | Fixr national (2026) |
| Epoxy crack injection, per crack | $250 to $1,000 | Fixr national (2026) |
| Waterproof paint or sealant, per sq ft | $1 to $8 | Fixr national (2026) |
The project and sealant rows give context and stay out of the math. Every figure is national, and Seattle labor tends to cost more than in many parts of the country, so read the range as a starting sketch rather than a local price. Digging along the outside of the foundation isn't priced. A backwater valve or a side sewer repair is plumbing, which belongs to a licensed plumbing contractor, so neither one is in the calculator; the cost guide covers them in words.
What the Result Means
A range like this works best as a yardstick for the real number. To get one, send the short request form; one independent local contractor will contact you about the project, look over the walls and write down the scope and price. In the meantime, the cost guide walks through what pushes prices up or down, and the wet basement checker can help sort out where the water is coming from.