Mold needs three things: spores, organic material, and moisture. The first two are everywhere on earth. The third is what makes Western Washington different: eight months of rain, marine humidity, and mild temperatures that never get cold enough to stop biological growth. Here, mold isn't a question of if; it's a question of where moisture is winning in your house right now.
Why Our Houses Are Built for It
Puget Sound housing stock works against us: vented crawl spaces sitting over damp soil, older homes with minimal insulation that breed condensation on cold surfaces, bathroom fans that vent into attics instead of outside, and decades of remodels that buried small leaks behind new finishes. Add a heating season where windows stay shut and indoor humidity climbs, and the conditions write themselves.
Where We Find It, Over and Over
- Crawl spaces, the regional champion: damp soil, poor ventilation, and nobody looks down there
- Attics: bathroom fans venting inside, roof leaks, and blocked soffit ventilation
- Window sills and closet walls: condensation on cold exterior surfaces, especially north-facing
- Behind and under things: furniture against exterior walls, kitchen kickspaces, washer connections
- Anywhere water damage was "handled" with a fan and hope
What Doesn't Fix It
Bleach on drywall treats the surface stain and misses the roots in the porous material, the growth returns. Painting over it (even with "mold-killing" primer) buries an active colony. And scrubbing without containment broadcasts spores through the house. These aren't just ineffective; they often make the eventual professional remediation bigger.
What Actually Fixes It: Moisture First, Then Removal
Every remediation that lasts starts with one question: why is this wet? Fix the source, the leak, the failed flashing, the crawl space humidity, the fan venting into the attic, and only then remove what's colonized, under sealed containment with negative air, clean and treat the structure, and verify. Skip the moisture step and you've bought a temporary cosmetic improvement at remediation prices.
Prevention That Suits Our Climate
Run bath and kitchen fans during and after use, and confirm they vent outside. Keep indoor humidity under about 50% in heating season (a $15 hygrometer tells you). Pull furniture a few inches off exterior walls. Look in your crawl space once a year, or have someone do it. And after any water event, dry fast and verify; within 24 to 72 hours is the window before mold establishes, which is why our water damage crews treat drying as mold prevention.