Finding water under your house is unsettling, and it's easy to put off dealing with it because you can't see it every day. But a crawl space that floods or stays wet affects the whole home, from the air you breathe to the strength of the floor framing. This guide covers how to spot the problem, what usually causes it, and when to call for help.
Signs there's water in your crawl space
- A musty or earthy smell inside the house, especially near floor vents.
- Hardwood floors cupping or buckling, or floors that feel soft or bouncy.
- Higher humidity indoors, condensation on windows, or a sticky feel to the air.
- A sump pump that runs constantly, or one that has stopped running after a storm.
- Insulation hanging down from between the floor joists.
- More bugs than usual, since moisture attracts pests.
If you notice any of these, look in the crawl space with a flashlight from the access door. Don't crawl in if there's standing water near electrical wiring or equipment.
What causes water in a crawl space
Rain and poor drainage
The most common cause is rainwater that isn't directed away from the foundation. Clogged gutters, short downspouts that dump water right next to the house, and soil that slopes toward the foundation all send water down along the foundation walls and into the crawl space.
High groundwater
After long periods of rain, the water table rises. In low spots, groundwater can push up through the crawl space floor even if your gutters are perfect.
Plumbing leaks
Supply lines, drain lines and water heater connections often run through the crawl space. A leak there can go unnoticed for weeks. A burst supply line can put hundreds of gallons under a house in a few hours. See burst pipes under the house.
Sump pump problems
If your crawl space has a sump pump, a power outage, stuck float switch, clogged intake or frozen discharge line can let water build up quickly. See sump pump failure.
Condensation
In humid Indiana summers, warm air entering through crawl space vents can condense on cool ductwork and pipes. That usually causes dampness rather than standing water, but over time it can still lead to mold.
Standing water under the house? Get it extracted and dried by a pro.
Call: (317) 426-0557Why you shouldn't wait
- Mold. The EPA advises drying wet materials within 24 to 48 hours to prevent mold growth.
- Wood rot. Joists, beams and subfloor that stay wet can soften and lose strength.
- Indoor air quality. Air from the crawl space moves up into the house, carrying moisture and musty odors with it.
- Damaged systems. Ductwork, insulation, wiring and HVAC equipment in the crawl space can be ruined by water.
What to do now
- Find and stop the source if you can. If it's a plumbing leak, shut off the water. If it's rain, make sure gutters and downspouts are flowing away from the house.
- Stay out of the water if electricity is involved. Keep away from standing water near outlets, wiring or appliances.
- Take photos. Document the water level and any damage for insurance.
- Get the water out and the structure dried. A restoration company can extract water and run commercial drying equipment until moisture readings are normal.
- Fix the cause afterward. Once it's dry, think about long-term fixes like better grading, downspout extensions, a sump pump with battery backup, or crawl space encapsulation.
Frequently asked questions
Is a little water in a crawl space normal?
Some dampness on the soil after heavy rain isn't unusual in older homes, but standing water is not normal. Puddles that last more than a day or two, or come back after every storm, mean water is getting in and should be dealt with.
Can water in the crawl space damage the house?
Yes. Standing water and high humidity can lead to mold, wood rot in the floor joists and subfloor, rusted ductwork, ruined insulation and pests. Moist air from below also rises into the living space.
Who do I call, a restoration company or a crawl space contractor?
If there is standing water or the crawl space flooded, call a water damage restoration company first to extract the water and dry the structure. Once it's dry, a crawl space or waterproofing contractor can fix the cause long-term with drainage, a sump pump or encapsulation.
How long does it take to dry out a crawl space?
It depends on how much water there was and how long it sat, but professional drying with dehumidifiers and air movers commonly takes several days. Crews take moisture readings until the wood is back to normal levels.