Black mold on Vashon is handled like any other mold: fix the moisture, remove or clean the growth with the area sealed off, and dry the structure before rebuilding. Color doesn't tell you how risky a mold is, so the size of the area and what it's growing on matter more. Call the number on this page to be connected with a local mold remediation company serving Vashon.
Island houses and slow drying
Vashon-Maury Island is unincorporated King County, about 15 miles from Seattle and reached by ferry. The county's subarea plan describes an aging housing stock, almost 90 percent single-family, with roughly a fifth of homes built in 1939 or earlier and about 1.9 percent mobile homes. The island holds almost half of King County's shoreline miles. Old framing, single-pane windows, cabins closed up for weeks, and shoreline homes in the damp marine air are all common settings for dark growth.
Steps to take first
- Stop the water. Check the roof, chimney flashing, plumbing and any gutter that dumps against the foundation. In a seasonal cabin, open it up, heat it and get air moving.
- Measure the patch honestly. Below about 10 square feet on a hard surface, EPA says a homeowner can usually clean it. Larger areas, or growth inside old plaster and lath walls, are a job for a professional.
- Keep people away from it. EPA advises people with asthma or weakened immune systems to stay out of moldy areas.
- Plan around the ferry. Companies coming from the mainland build ferry time into scheduling and sometimes into the bid, so ask how they price travel.
- Check flood mapping before rebuilding. King County maps a coastal floodplain around the island plus a Sea Level Rise Risk Area. Substantially improved buildings there must sit at least 3 feet above base flood elevation, and King County Permitting answers those questions.
What you see and the usual source
| What you see | Likely cause |
|---|---|
| Black growth on old window sashes and sills | Condensation on single-pane glass through the wet months |
| Dark stains on subfloor or joists seen from below | A damp crawl space or a plumbing leak |
| Spotted walls in a cabin that sat closed all winter | No heat and no air movement while humidity stayed high |
| Dark patches under a skylight or around a chimney | Failed flashing letting rain into the ceiling |
Cost factors
Angi's Seattle cost guide lists a typical remediation at $1,008 to $2,967, a crawl space at $425 to $1,650, and a whole house at $8,275 to $24,800. On the island, travel and ferry time can add to that. The amount of material removed, access under the house, and repairs to older finishes move the number most. Building permits for unincorporated Vashon come from the King County Department of Local Services Permitting Division. Whoever does the work should be registered with Washington L&I as a construction contractor.
Black Mold Removal questions in Vashon
Is black mold on crawl space joists a serious problem?
Does Washington license black mold removal companies?
What can a renter do about black mold the landlord won't fix?
Will homeowners insurance pay for black mold removal?
More mold services in Vashon
Black Mold Removal nearby
Sources
- King County: Vashon-Maury Island Subarea Plan (2024)
- King County: Vashon sea level rise FAQ
- King County Local Services: Code enforcement and permitting
- EPA: Mold Cleanup in Your Home
- Washington State Department of Health: Mold
- RCW 59.18.070: Landlord failure to carry out duties
- Washington L&I: Register as a Contractor
- Angi: Mold Remediation Cost in Seattle
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