Des Moines sits on a broad slope down to Puget Sound cut by creek ravines, and many homes are old enough that drainage and ground covers may be worn out. That combination keeps crawl spaces wet and lets mold settle on joists and subfloor. Call the number on this page to be connected with a local mold remediation company in Des Moines.
Crawl spaces on the slope
Des Moines is a waterfront city about 16 miles south of Seattle, stretching from Pacific Highway down to the Sound through neighborhoods such as Redondo, Woodmont and Zenith. The ravines of Des Moines Creek and Massey Creek cut across that slope. Uphill foundation walls can collect groundwater, and houses near ravines stay damp longer. The city's median home was built in 1974, so many crawl spaces have original or patched ground covers and drainage that no longer keeps up with a Puget Sound winter.
What to do now
- Look for the water first: a dripping pipe, a downspout dumping against the foundation, or a wet uphill wall.
- Fix or stop what you can, such as extending downspouts and clearing gutters.
- Don't spray bleach or paint across the joists; EPA says not to paint or caulk over mold.
- If heating ducts run through the space and you think they're contaminated, leave the system off, as EPA advises.
- Take photos of the growth, any water lines and damaged insulation for your records and your insurer.
- Have a company crawl the whole space and give you a written scope.
What you see and what it usually means
| What you see | Likely cause |
|---|---|
| Growth heaviest along the uphill wall | Groundwater seepage or surface runoff |
| Mold under a bathroom or kitchen | Plumbing leak or a drain line dripping |
| Even, light growth across most joists | Damp air and wet soil with a poor or missing ground cover |
| Wet, sagging batts | Long-term condensation or a leak above |
| White crust on concrete | Mineral salts from water moving through the foundation |
Cost factors
Angi's Seattle cost guide lists crawl space mold removal at $425 to $1,650; the 2026 national range from HomeGuide is $1,500 to $4,000. In Des Moines, price follows the area of affected framing, how tight the space is, how much insulation comes out and whether drainage, gutter or ground cover work is folded in. If rotted wood has to be replaced, the City of Des Moines Building Division issues building permits and inspects the work. Washington has no state mold license or certification, so check that the company is registered with Washington L&I as a construction contractor.
Crawl Space Mold Removal questions in Des Moines
I rent. Who deals with a wet, moldy crawl space?
Will spraying a sealant or coating over the mold fix it?
What should a crawl space inspection include?
What does crawl space mold removal cost?
More mold services in Des Moines
Crawl Space Mold Removal nearby
Sources
- Wikipedia: Des Moines, Washington
- City-Stats: Des Moines, WA
- City of Des Moines: Building Division
- City of Des Moines: Report a Concern
- Public Health - Seattle & King County: Mold (tenants and landlords)
- EPA: Mold Cleanup in Your Home
- Angi: How Much Does Mold Remediation Cost in Seattle, WA?
- HomeGuide: How Much Does Mold Removal and Remediation Cost? (2026)
- L&I: Verify a Contractor, Tradesperson or Business
- RCW 59.18.060: Landlord, Duties
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