Keeping mold out of lakefront homesafter any water gets in

Moisture is the only part of the mold equation that you can control, and it is harder to control on the lake. Published Everett normals show about 5.8 inches of precipitation in November, with December and January near 5, and shoreline lots can stay wet underfoot for long periods. A crawlspace over saturated soil adds moisture to the air under the floor. Big lake-facing windows and older cold walls then give that moisture somewhere to condense. So after a leak, your house may already be holding more moisture than one up the hill.

The general advice is on our main mold prevention page. The EPA says to dry wet materials within 24 to 48 hours, and its flood guidance notes that mold can grow on materials that stay wet for more than 24 hours. ^{[2] [1]} On the shoreline, this means starting immediately and paying particular attention to what is under the floor and behind the coldest walls.

It is tempting to throw the windows open when the rain stops. Sometimes that helps. But the air near a large lake in the wet season may carry quite a lot of moisture. Compare indoor and outdoor humidity and temperature with a basic meter before you decide. Modelled data for Lake Stevens from Open-Meteo suggests even wetter conditions than Everett's station shows, although we label it as modelled since it may read high. Either way, a closed room with a dehumidifier is usually the more reliable option in winter.

In the summer the picture reverses. Warm, dry days are ideal for airing out a home and drying cabin-era corners, and it is a good time to get stored things out into the air. Use that season to deal with the rooms that gave you trouble over the winter.

A home used mainly in summer is at high risk, because nobody is there to notice a leak, and closed rooms stay still and damp. If you return to find a leak after several weeks away, keep in mind that mold may already have started. Washington's flood guidance suggests that where a flooded home has been shut up for several days you should step in just long enough to open it up, then stay outside for half an hour or more. Photograph what you find before you clean anything.

If you see growth, hold off on fans and dehumidifiers until visible mold has been gently cleaned, as the EPA advises, so that you do not spread it around. Washington's Department of Health advises hiring a professional if mold covers a larger area than a 3-foot by 3-foot patch, if it is in hidden places or if it has been contaminated by sewage. A humidity sensor with an alert on your phone is a modest way to keep an eye on an empty house.

Flood water changes the plan. If lake water came inside, cleanup comes before prevention. Highly absorbent materials that cannot be cleaned and dried belong in the trash, according to the EPA. The agency also says that people with asthma or weak immune systems ought to avoid both moldy sites and flood cleanup, and that children and pregnant people ought to leave flood cleanup to others. Do not use the HVAC system to help with drying if any part of it was touched by flood water. Have it cleaned and checked by a professional first.

If water is still under the house, moisture may keep rising into the rooms. Keep humidity down with a dehumidifier upstairs, take out wet insulation below, and plan to return to the crawlspace once the ground dries out. Check any contractor on Washington L&I's Verify tool, and note that Washington has no specific certification requirement for mold or water damage work, the Department of Health says. ^[7] So ask about training and experience.