From November through January, Tacoma gets about six inches of rain a month while homes stay shut and heated. Here is how condensation forms on cold walls, how to keep it in check, and when a problem goes beyond cleaning.
Most of Tacoma's indoor damp does not come through the roof. It comes from warm air inside a closed house meeting a cold wall. That is the state's own explanation, and it means a lot of the solution lies in everyday habits rather than in stronger products.
Here is how moisture behaves in a South Sound home, and what you can do about it.
The Tacoma No. 1 station averages 40.81 inches of precipitation a year, with about 96 days of at least 0.10 inch. November leads at 6.50 inches, and December and January each get about 6, with about 13 wet days a month. Highs in December through February average just 48.6 degrees, so nothing dries quickly outside.
The Washington State Department of Health says indoor mold often grows where warm moist air condenses on cooler wall surfaces, such as cold exterior walls, behind dressers and headboards, and in closets. Those are the spots to check first, and they are places a regular dusting tends to miss.
Age plays a part as well. About 64 percent of Tacoma homes predate 1980, and houses from that long ago may have less insulation behind the wall surface, so it pays to look carefully on the coldest side of the house. North facing bedrooms, unheated rooms and the corners behind big furniture are the usual suspects, since air barely moves there and the wall stays cold all day.
Daily living adds a lot of water to indoor air, from showers and cooking to wet coats and drying laundry, and these habits help it leave.
Tacoma Water says pink stains on drains, toilet bowls and pet dishes usually come from an airborne bacteria unrelated to the drinking water, one that thrives in damp areas. Keeping surfaces dry helps. Wipe drains and shower corners regularly with a bathroom cleaner, and do not be alarmed if the ring comes back during the wet months. It is a nuisance rather than a verdict on your housekeeping, and it responds well to a simple weekly routine.
Blue stains are different. Tacoma Water says they come from water sitting in copper pipes, and it suggests running water about 30 seconds after six hours unused and keeping fixtures dry and drip free. Soft water may play a part in how much film you see too, since less soap is needed for washing, and extra soap leaves residue that holds on to damp.
Regular cleaning limits what surface mildew can grow on. A bi-weekly Recurring House Clean keeps baths on a schedule, and a One-Time Deep Clean reaches blinds, tracks and baseboards where film builds up.
It does have limits. The Department of Health defines a small mold area as less than about ten square feet, and it suggests professional help for larger areas. Growth that keeps returning points to a moisture source that needs repair. TotalCare Cleaning does not provide mold or water damage remediation. If you rent, tell your landlord in writing as soon as you notice a problem, and take a dated photo.
The questions Tacoma homeowners ask most often about this topic, answered plainly.
TotalCare Cleaning will service Tacoma and surrounding areas with background-checked cleaners and is insured up to $1 million. Re-clean guarantee: if we missed something, tell us by the end of the next day and we come back to fix it. Beyond Clean. TotalCare.
