Crawl Space Mold Removal in Redmond, WA

Does the Sammamish River affect crawl spaces in Redmond?

Near the river, it can. The Sammamish leaves Lake Sammamish at Marymoor Park and runs north along the west edge of downtown, about 10 miles east of Seattle. King County says high water in Redmond can limit access to NE 95th Street and low sections of the Sammamish River Trail and back water up into stormwater facilities, and farmland between Redmond and Woodinville floods when the river is high and upland stormwater can't drain. When stormwater can't get away, yards and foundations nearby stay wetter, and crawl spaces in low spots pay for it. On higher ground such as Education Hill and Overlake, the cause is the wet season itself: damp air through the vents and soil that stays wet for months.

My house was built in the 1980s. Should I check the crawl space?

It's worth a look. Redmond's median home was built in 1984, and after four decades many crawl spaces have a ground cover that's torn or pushed aside, insulation that has sagged, and gutters or downspouts that no longer move water far enough from the foundation. A musty smell in ground-floor rooms, growth on joists and wet batts are the common signs. A remediation company should crawl the entire space, take moisture readings and photograph what it finds. Angi's Seattle cost guide lists crawl space mold work at $425 to $1,650; HomeGuide's 2026 national range is $1,500 to $4,000.

I rent. Will the city deal with mold under my unit?

Not directly. Redmond Code Enforcement says it doesn't oversee general property maintenance issues such as mold, and it acts only when conditions meet the state definition of substandard or dangerous housing under RCW 59.18, after the tenant has notified the landlord in writing. Landlord-tenant disputes are civil matters. Start with written notice to your landlord about the leak or dampness; Washington landlords must keep units reasonably weathertight and give tenants Department of Health-approved mold information. This is general information, not legal advice.

A Redmond note

If removal uncovers rotted sill plates or a leaking pipe, the City of Redmond Development Services Center reviews and issues construction permits. Washington has no state mold license or certification, so check the company's construction contractor registration on L&I's Verify a Contractor tool.