For Des Moines homes, mold testing is the right call when a damp smell has no visible cause, when a lease or sale needs written results, or when you want clearance after remediation. If you can see mold, EPA says sampling usually isn't needed. Call the number on this page to be connected with a local mold inspector in Des Moines.
Des Moines spreads down a broad slope to Puget Sound, cut by the ravines of Des Moines Creek and Massey Creek. The median home was built around 1974, and only about 61 percent of homes are owner-occupied, so plenty of residents rent. Hillside lots, aging houses and a long wet season add up to frequent questions about hidden mold, from Redondo to Woodmont and Zenith.
What to do before you book a test
- Look first. Check under sinks, around windows, in closets on outside walls and in the crawl space or lower level. If you find growth, you may not need a lab at all.
- Find the water. A musty smell almost always means something is staying damp. Note stains, soft drywall and condensation.
- Write down the story: when the smell started, past leaks, and whether it is worse in wet weather.
- If you rent, give your landlord written notice of the leak or moisture problem. If it isn't fixed, the City of Des Moines takes code enforcement complaints online. Public Health - Seattle & King County does not do mold assessments. General information, not legal advice.
- Decide what you want the test to answer: is there hidden growth, did a cleanup work, or do you need documentation?
What you see and what it might mean
| What you notice | Likely cause | Testing role |
|---|---|---|
| Musty smell in a lower-level room on the downhill side | Groundwater seepage through a foundation wall | Air sample can help if no growth is found |
| Black specks on window frames each winter | Condensation on cold glass | Not needed; clean and improve ventilation |
| Stained ceiling below a bathroom | Leaking tub, shower or failed fan | Swab can confirm growth; repair is the real fix |
| Odor after a plumbing leak was repaired | Wet material left inside the wall | Wall-cavity air sample or moisture readings |
What affects the price
Angi's 2026 national data puts combined air and surface testing at $250 to $500, and HomeGuide's 2026 national range for a bulk sample is $100 to $350. In Des Moines the total depends on the number of samples, crawl space access, the size of the home and how quickly you want results. Ask whether the price includes an outdoor control sample and a written report. If repairs follow, the City of Des Moines Building Division issues building permits for structural and drywall work, and Washington L&I's Verify tool shows whether a contractor is registered.
Mold Testing questions in Des Moines
Do I need a mold test if I can already see mold?
I rent. Should I order a mold test myself?
Will the county health department test my home for mold?
What is the difference between an air sample and a surface sample?
More mold services in Des Moines
Mold Testing nearby
Sources
- EPA: Mold Information Slideshow (testing and sampling)
- Washington DOH: Mold
- Angi: How Much Does a Mold Inspection Cost? (2026 data)
- HomeGuide: How Much Does a Mold Inspection Cost? (2026)
- L&I: Verify a Contractor, Tradesperson or Business
- RCW 59.18.070: Landlord's failure to remedy, Tenant's remedies, Notice
- Public Health - Seattle & King County: Mold
- City of Des Moines: Report a Concern
- City of Des Moines: Building Division
- City-Stats: Des Moines, WA
- U.S. Census QuickFacts: Des Moines city, Washington
- Wikipedia: Des Moines, Washington
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