How do I dry out a wet crawl space?

When a crawl space gets wet, time is your biggest enemy. Moisture leads to mold, wood rot, and structural damage faster than most homeowners realize. As a waterproofing expert, my first priority is helping you stop the damage before it gets expensive.

Drying out a crawl space isn’t as simple as opening a window (I wish it were). In fact, that can sometimes make it worse. Here is my professional advice and a step by step process to getting your crawl space bone dry and keeping it that way.

Table of Contents

1. Safety First: Before You Enter
2. Step 1: Remove Standing Water
3. Step 2: Clear Out Moisture
4. Step 3: Drying the Soil 
5. Step 4: Find and Fix the Source
6. Preventing Future Flooding

Safety First: Before You Enter

If you have standing water in your crawl space, do not enter until you have checked for these two hazards:

• Electrical Risks: Ensure no submerged outlets, extension cords, or exposed wiring are in contact with the water. If in doubt, turn off the power to your crawlspace.
• Structural Integrity: Heavy flooding can soften the soil around footings. If the ground feels mucky or unstable, call a pro.

Speaking of which, if you don’t want to be the one to check out under your crawlspace, we’ll do it for you. That’s what I pay the crew for after all. 

Step 1: Remove Standing Water

You cannot air dry a puddle. You must physically move the water out.

• For Puddles: Use a heavy-duty wet/dry vacuum.
• For Flooding: If there are several inches of water, use a submersible utility pump with a garden hose attached to discharge the water at least 15 feet away from your foundation.

Step 2: Clear Out Moisture

Once the standing water is gone, you need to remove anything that holds onto moisture:

• Wet Insulation: If your fiberglass insulation is wet, it’s ruined and becomes a breeding ground for mold. Rip it out. 
• Debris: Remove wet cardboard boxes, wood scraps, or old vapor barrier remnants that are trapping water against the soil.

Oh, and please be sure to wear the right gear too. Safety first, my friend.

Step 3: Drying the Soil

Now you need to pull the moisture out of the wood beams and the air.

• Industrial Fans: Place industrial fans at opposite corners to create a vortex of airflow. (Side note: standard house fans may be too weak for this).
• Commercial Dehumidifier: A standard basement dehumidifier often can’t handle the low temperatures of a crawl space. A crawl space-specific unit could help pump out all that water. If you do decide to run a dehumidifier, close your foundation vents if you have any. If you leave them open, you are effectively trying to dehumidify the world. Which just won’t work I’m afraid. 

Step 4: Find and Fix the Source

A dry crawl space won’t stay dry unless you find out how the water got there.

• Plumbing Leaks: Check for sweating pipes or slow drips from the subfloor above.
• Surface Water: Check your gutters. If they are clogged or the downspouts are too short, rainwater is being funneled directly into your crawl space.
• Groundwater: If water is seeping through the concrete walls, you likely have a high water table and need a permanent drainage solution like french drains and/or a sump pump.

Ready to Stop the Cycle?

Drying your crawl space once is a chore; drying it every time it rains is a nightmare. To prevent this from happening again, I recommend a permanent vapor barrier or full encapsulation which we can help with. Schedule your free estimate and skip the hassle of drying out your crawl space. We can do that for you.