Mold Testing in Redmond, WA

Does my Redmond home really need a mold test?

Often not. The median house in Redmond was built around 1984, so many homes are old enough for original windows, roof vents and bath fans to underperform, but not so old that problems hide easily. Through the gray months, condensation on cold glass, bathrooms that don't fully dry, and closets on outside walls are the usual sources. A moisture-focused inspection finds most of them. Testing becomes worthwhile when the odor stays and the inspection finds nothing, when a buyer or landlord needs documentation, or after remediation for clearance. EPA notes there are no federal limits for mold, so a test is a comparison against outdoor air, not a pass or fail.

I rent. Will the city check for mold?

No. Redmond Code Enforcement says it does not oversee general property maintenance issues such as mold, pests or odors. It acts only when conditions meet the state definition of substandard or dangerous housing under RCW 59.18, and only after the tenant has notified the landlord in writing; landlord-tenant disputes are civil matters. So the practical path is written notice to your landlord about the leak or moisture problem, then the city if the condition rises to that level. Washington landlords must give tenants Department of Health-approved mold information and keep units reasonably weathertight. General information, not legal advice.

What does a test cost, and who should do it?

Angi's 2026 national data lists a basic air test at $250 to $350 and swab tests at $200 to $300; HomeGuide's 2026 national range for bulk samples is $100 to $350. Totals depend on sample count, home size, crawl space or attic access and lab turnaround. Washington has no state mold license or certification, so ask about training and look at a sample report. Angi suggests choosing a tester who doesn't also sell the removal.

One local note

Downtown Redmond sits just north of Lake Sammamish, and the Sammamish River runs along its west edge from Marymoor Park. King County says river flooding can limit access to NE 95th Street and low sections of the Sammamish River Trail and can back water into stormwater facilities. If water reached your home, EPA says to treat materials that stayed wet beyond 24 to 48 hours as moldy; permits for rebuilding go through the Redmond Development Services Center.