On Vashon-Maury Island, mildew most often shows up in older homes, closed-up cabins and waterfront houses where damp air and cool surfaces meet for months at a time. Small surface patches are usually a homeowner job; larger growth, soft drywall or a problem that keeps coming back calls for a professional. Call the number on this page to be connected with a local mold remediation company in Vashon.

Island homes and damp air
Vashon-Maury Island holds almost half of King County's shoreline miles, and much of its housing is older: the county's subarea plan calls the stock aging, with roughly a fifth of units built in 1939 or earlier. Almost 90 percent of homes are single-family, and about 1.9 percent are mobile homes. Older houses, seasonal places shut for weeks and homes close to the water all offer what mildew needs: cool surfaces, still air and slow drying.
What to do now
- Open up and dry out. If a cabin or spare room has been closed, heat it, run fans and let it air before judging how bad things are.
- Size it up. EPA and Washington DOH say growth under about 10 square feet on hard surfaces is usually manageable for a homeowner.
- Clean, don't cover. Detergent and water on hard surfaces, then dry. Don't paint or caulk over mildew.
- Bag up what's ruined. Mattresses, cushions and carpet that stay musty after drying usually aren't worth saving.
- Look for the water. Roof and window leaks, gutters spilling against siding and missing bath fans are common culprits in older homes.

Signs and what they usually mean
| What you see | Likely cause |
|---|---|
| Speckles across painted walls in a shut room | Stale, humid air with no heat or ventilation |
| White or gray film on furniture, books or leather | Long stretches closed up through the wet season |
| Growth under windows facing the water | Condensation and wind-driven rain on older frames |
| One ceiling spot that keeps coming back | A roof or flashing leak above it |
| Musty floors in a manufactured home | Damp air under the home or a plumbing leak |
What affects the price
Angi's Seattle cost guide lists most mold work at $10 to $25 per square foot and bathroom jobs at $425 to $825. The island depends on ferry service, so ask how a company handles travel time. Removing trim, drywall or flooring and repairs afterward add the most. Building permits for repairs in unincorporated King County come from the King County Department of Local Services Permitting Division, and substantially improved buildings in the coastal floodplain or the island's Sea Level Rise Risk Area must be built at least 3 ft above base flood elevation.
Mold & Mildew Cleanup questions in Vashon
Why does a closet or back bedroom smell musty?
Can mildewed furniture, rugs or clothes be saved?
Will a dehumidifier stop mildew?
Does Washington license mold and mildew cleanup companies?
More mold services in Vashon
Mold & Mildew Cleanup nearby
Sources
- King County: Vashon-Maury Island Subarea Plan (2024, pdf)
- King County: Vashon sea level rise FAQ (pdf)
- King County Local Services: Code enforcement and permitting
- EPA: Mold Cleanup in Your Home
- EPA: A Brief Guide to Mold, Moisture and Your Home
- Washington State Department of Health: Mold
- Washington State Department of Health: Hiring a Contractor (indoor air)
- Washington L&I: Verify a Contractor
- Angi: Mold Remediation Cost in Seattle
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