Signs you have water under the house
- A musty or earthy smell inside, worst in the rooms right above the crawl space.
- Floors that feel soft, cold or damp, or hardwood that has started to cup.
- Insulation hanging down between the floor joists, or lying on the ground.
- Higher humidity in the house, condensation on windows, or more spiders and bugs than usual.
- A puddle or standing water when you lift the crawl space hatch.
Many Lynnwood homeowners never go into the crawl space, so problems sit there for months. A sudden smell after a week of heavy rain is often the first clue.
How crews dry a wet crawl space
- Find the source. It is usually one of three things: groundwater coming in during long rains, a plumbing leak under the floor, or a downspout dumping water against the foundation.
- Pump out standing water and remove wet insulation and torn vapor barrier.
- Dry the space with dehumidifiers and air movers, checking the joists and subfloor with moisture meters.
- Treat and clean mold on wood framing when there is growth.
- Recommend what to fix so it does not come back, such as a new vapor barrier, downspout extensions, or a sump pump.
Why Lynnwood crawl spaces get wet
Lynnwood gets most of its rain between October and April, and when an atmospheric river parks over Puget Sound the ground stays soaked for days. Water that can't soak in follows the slope of the lot, and on many streets that slope runs toward the house. The low ground along Scriber Creek, Hall Creek and Swamp Creek tends to stay wet the longest.
Plenty of houses from the 1960s and 70s were built over vented crawl spaces with thin plastic on the dirt and fiberglass batts in the floor. After decades, the plastic has torn or slid away and the batts are falling down. Add a damp winter and you get the musty smell, the cold floors and, eventually, mold on the joists.
Mold on framing does not need to be a disaster if someone deals with it early. Drying the space and fixing the water source matters more than any spray.