Waterproofing in Seattle: what to know
Seattle has mild temperatures and long, damp rainy seasons from fall through spring. Moisture, moss on roofs and mold in basements and crawl spaces are the most common local issues.
- Winter storms can expose leaks in stucco, windows and hillside retaining walls.
- Long rainy seasons make crawl-space and basement waterproofing one of the most common local jobs.
How much does waterproofing cost?
- Basement waterproofing: $3,200 – $10,700
- Sump pump installation: $860 – $2,150
- Sump pump repair: $160 – $540
Estimate only. Typical price ranges based on public US cost data, adjusted by state. Your actual quote comes directly from the pro and depends on your home and the job.
Get a quote from a local pro →How it works
Where is water entering, when does it happen, and has the area been repaired before? Describe the problem, add your ZIP code and when you need help, and we look for an available local professional in the Seattle area. The request takes about 2 minutes, is free, and your address stays private until a professional is assigned.
Frequently asked questions
Do I need a permit for waterproofing work in Seattle?
Interior sealing usually does not need a permit, but excavation, new drains or sump pump discharge lines may. In Seattle, permits are typically handled by the Seattle Department of Construction and Inspections (SDCI). Rules change, so confirm with them before work starts.
Which parts of Seattle do you cover?
Requests are accepted from anywhere in the Seattle area, including Capitol Hill, Ballard, West Seattle, Queen Anne and Beacon Hill. Availability depends on local professionals in your ZIP code.
How much does waterproofing cost in Seattle?
Typical price ranges for Washington are shown in the cost estimate above. The final price depends on the job, materials and access, and the professional gives you a quote before any work begins. Sending a request is free.