Water in the Crawl Space: Causes, Cleanup and How to Keep It Dry
Short answer: Water in a crawl space usually comes from poor grading, gutters that dump water by the foundation, a plumbing leak or groundwater. Keep the power off in the area, stop any leak, pump out standing water and dry the soil and framing. To keep it dry, slope soil away from the house, extend downspouts and lay a sealed vapor barrier over the ground.
Most people rarely look in their crawl space, so water can sit there for a long time. Meanwhile it soaks insulation, feeds mold on the floor joists and sends musty air into the house. If you've found standing water, ReestorianPros can connect you with a local provider for flooded basement and crawl space cleanup in Littleton.
This is general information. Crawl spaces can hold electrical wiring and ductwork, so be careful entering one with water in it.
Is water in a crawl space normal?
Standing water is not normal, and it's not something to wait out. A crawl space should be dry. Use this as a rough guide:
| What you see | What it usually means |
|---|---|
| Soil slightly damp after a heavy storm, dry a day later | Surface runoff reaching the foundation; fix grading and gutters |
| Puddles that stay for days | Drainage problem or groundwater |
| Water under one spot near a bathroom or kitchen | Plumbing leak |
| Wet insulation hanging from the floor above | Leak from above, or long-term humidity |
| Musty smell in the house | Ongoing moisture, possibly mold |
| White mineral deposits on foundation walls | Water moving through the wall |
What causes water in a crawl space?
- Poor grading. Soil that slopes toward the house sends rain and snowmelt straight to the foundation.
- Gutters and downspouts. Clogged gutters overflow, and short downspouts dump water at the wall.
- Plumbing leaks. Supply lines, drains and water heater lines often run through the crawl space.
- Irrigation. Sprinklers that spray the foundation or leak near the house.
- Groundwater. A high water table or saturated soil can push water up through the floor.
- Condensation. Humid air hitting cool surfaces, such as ducts and pipes.
To rule out a plumbing leak, Denver Water suggests turning off all water use, noting the meter and checking it again after at least 30 minutes. If it moved, there's a leak.
Water standing in the crawl space? Call to reach a local provider to pump it out and dry the framing.
Call (303) 879-0950How to get water out of a crawl space
- Stay safe. Don't enter standing water if wiring, a furnace or a water heater could be energized. The CDC warns never to touch electrical equipment while standing in water. Turn off power at the panel if you can reach it from a dry spot.
- Stop the source. Shut off the main water valve for a plumbing leak. Redirect downspouts or sprinklers if runoff is the cause.
- Pump out standing water. A submersible or utility pump moves most of it; a wet vac handles the rest.
- Remove wet materials. Sagging or soaked insulation and damaged vapor barrier usually need to come out.
- Dry the space. Air movers and a dehumidifier dry the soil, framing and subfloor. ENERGY STAR notes that standard dehumidifiers may not work well in spaces that regularly drop below 65°F, because the coils can frost.
- Check for mold on the joists and subfloor once the area is dry.
- Fix the cause before putting in new insulation or a vapor barrier.
If the water came from a sewer line or from outside flooding, treat it as contaminated. Wear rubber boots, gloves and eye protection, and consider a professional. See Category 1, 2 and 3 water for why that matters.
How long does it take to dry a crawl space?
It depends on how much water there was, how long it sat and how well air moves under the house. A small, fresh plumbing leak can dry in a few days with air movers and a dehumidifier. A crawl space with standing water, soaked soil and wet insulation can take a week or more. Drying is done when moisture readings in the joists and subfloor are back to normal, not when the soil surface looks dry.
Damage water can cause under the house
| Problem | Why it happens |
|---|---|
| Mold on joists and subfloor | Damp wood and still air |
| Wood rot | Framing that stays wet for months |
| Sagging insulation | Fiberglass batts soak up water and fall |
| Musty odors upstairs | Air from the crawl space rises into the house |
| Rusted ductwork and pipes | Constant humidity |
| Pests | Many insects are drawn to damp spaces |
The EPA says mold usually won't grow if wet materials are dried within 24 to 48 hours. In a crawl space that stays wet, growth is likely, so dry it quickly.
How to keep water out of a crawl space
Fix the grading
The Colorado Geological Survey's homeowner guide recommends that soil slope away from the house: at least 5 percent in planted areas, and about 10 percent within the first 10 feet of the foundation. That's roughly 12 inches of fall over those first 10 feet.
Move roof water away
The same guide says downspouts should discharge at least 5 feet from the foundation. Clean gutters each fall and spring, and add extensions where needed.
Keep sprinklers back
Sprinklers shouldn't spray closer than 5 feet from the foundation, according to the Colorado Geological Survey. Fix leaking heads and lines near the house.
Lay a vapor barrier
The Building America Solution Center recommends covering the crawl space floor with polyethylene sheeting at least 6 mil thick. Seams should overlap 6 to 12 inches and be sealed. The sheeting should run up the walls and piers and be fastened in place. It says the ground cover keeps ground moisture and soil gases out, whether the crawl space is vented or not.
Add a sump pump if water keeps rising
Where groundwater keeps coming up through the floor, a sump pit and pump at the low point can remove it. Read sump pump failure for how to keep one working.
Control humidity
A dehumidifier helps in an enclosed crawl space. See what humidity a basement should be for the same targets. ENERGY STAR says relative humidity of about 30 to 50 percent is generally ideal indoors, and suggests dehumidifiers sized to how damp the space is.
Should you encapsulate your crawl space?
Encapsulation means sealing the crawl space: a heavy ground cover, sealed seams, covered walls and closed vents, often with a dehumidifier or a little conditioned air. The Building America Solution Center recommends insulated, unvented crawl spaces in humid climates, and says a ground cover belongs in every crawl space, vented or not. Colorado is drier, so the right answer depends on your house. Before sealing anything, fix grading, gutters and leaks, and ask the contractor how the space will stay dry and how combustion appliances in the area will get the air they need.
What affects the cost of crawl space water cleanup?
ReestorianPros doesn't set or publish prices. The cost depends on:
| Factor | Why it matters |
|---|---|
| How much water and for how long | More water and time means more drying and more damage |
| Water category | Sewage or floodwater adds sanitizing and material removal |
| Access | Low clearance and small openings slow the work |
| Insulation and vapor barrier | Wet insulation and barrier usually need replacing |
| Mold on framing | Adds cleaning or remediation |
| The fix for the cause | Grading, gutters, plumbing or a sump pump are separate costs |
Ask for a written estimate that separates the water removal and drying from repairs and drainage work.
Crawl spaces in Littleton homes
Many Littleton-area homes have full basements, but split-levels, older homes and additions often have a crawl space under part of the house. These areas get checked far less often than a basement. Colorado's expansive clay soils add another reason to keep water away: the Colorado Geological Survey calls swelling soil a common and sometimes serious problem in the state, and wetting the soil next to the foundation is what makes it move.
Local note: Crawl space water shows up differently around the area. In Lakewood and Englewood, older homes and additions may have a crawl space beside the basement. In Ken Caryl, sloped foothill lots can send runoff toward the uphill side of a house. In Centennial, some split-level homes have a crawl space beneath one level.
Related reading: If the water reached the basement, follow the basement flood checklist. If you have a pump, learn the signs of sump pump failure.
When should you call a water damage professional?
Call a professional when:
- Water is standing in the crawl space or keeps coming back
- Insulation is soaked or falling down
- You see mold on the joists or subfloor
- The water may be sewage or outside floodwater
- You need moisture readings and photos for an insurance claim
Water in the crawl space in Littleton? Call (303) 879-0950 to reach a local water damage provider.
Frequently asked questions
Is water in a crawl space normal?
Standing water isn't normal. A little dampness on the soil after a storm can happen in vented crawl spaces, but pooled water, wet insulation or water that stays for days points to a drainage problem or a leak that needs fixing.
How much water in a crawl space is OK?
None should stand there. Any water you can see pooling, or soil that stays muddy, is worth tracking down. Ongoing moisture leads to mold, wood rot and pests.
Who do I call for water in the crawl space?
Call a plumber if a pipe is leaking. Call a water damage provider to pump out the water and dry the framing. For repeated groundwater or runoff problems, a drainage or foundation contractor can look at grading, gutters and sump options.
How do I get water out of a crawl space?
Stop the source if it's a pipe, keep power off in the area, then remove standing water with a submersible or utility pump and a wet vac for what's left. Drying the soil, framing and insulation afterward is the part that prevents mold.
Does a vapor barrier stop water in a crawl space?
A vapor barrier stops ground moisture from rising into the crawl space, but it doesn't stop liquid water flowing in. Fix grading, gutters and leaks first, then put down the barrier.
Sources
- Building America Solution Center (PNNL): Capillary break beneath crawlspace floors
- Colorado Geological Survey: SP-14 Home Landscaping and Maintenance on Swelling Soil
- ENERGY STAR: Dehumidifiers
- EPA: A Brief Guide to Mold, Moisture and Your Home
- Denver Water: Leaks
- CDC: Guidelines for Cleaning Safely After a Disaster
Related guides
What to Do If Your Basement Floods: A Step-by-Step Guide
Ten steps for a flooded basement, from safety and the power panel to drying, insurance and stopping it from happening again.
Sump Pump Failure: Warning Signs, Causes and What to Do
How sump pumps work, the warning signs of failure, what to do when the pit overflows and how to test and back up your pump.
Standing water under the house?
Call to reach a local provider who can pump out the crawl space and dry the framing.