What's the first thing to check if my crawl space has water?

Your gutters and downspouts during a heavy rain. Overflowing gutters and downspouts that empty near the foundation are common causes.

How deep is an interior French drain in a crawl space?

Ours are about 8–10 inches deep and set about 12–18 inches from the foundation wall, with a sump pump at the lowest point.

Why does my crawl space still get water after fixing my gutters?

Settling opens cracks in the foundation wall, and brick and concrete are porous. An interior French drain handles what still gets in.

What Should I Do About Water in My Crawl Space?

Start outside. Fix gutters and downspouts that dump water near the foundation, then correct any grading that sends water toward the house. If water still gets in, and it often does, the industry-standard fix is an interior French drain around the crawl space perimeter, with a sump pump at the low point to send the water away.

Step 1: Roof water

The best time to inspect outside your home is during a heavy rain. Look for:

Water overflowing clogged or damaged gutters
Downspout seams that aren't fully connected and are leaking
Downspouts that empty right next to the foundation

For downspouts that drain near the house, add above-ground or buried downspout extensions to carry the water away. A landscaping or crawl space contractor can often do this. If you're not comfortable repairing gutters yourself, hire a reputable, insured gutter contractor.

If your home has no gutters, talk with a crawl space inspector about the current condition of your crawl space. If there's no significant mold or high wood moisture yet, and doing both isn't in the budget right now, you may want to put gutters first.

Step 2: Ground water

Look for anywhere your yard slopes toward the house. The goal is to keep excess ground water from reaching the foundation.

Moderate slopes can often be handled with exterior French drains or larger drainage systems.
Steep grades may need terracing and retaining walls with drainage.

We recommend a grading or landscaping contractor for these jobs, since they can pull any required permits and warranty their work. After any major changes outside, check the crawl space again during a heavy rain to make sure the water is gone.

Step 3: Inside the crawl space

It's common to still get some water in the crawl space even after fixing the gutters or adding exterior drainage. That's just the nature of water and below-grade foundations:

As a house settles, gaps and cracks form in the foundation wall, giving water an easy way in. Water takes the path of least resistance, so if those paths exist you may still see some water, hopefully much less.
Brick and concrete are porous. Where part of the wall is below ground, water can bleed right through, especially in heavily saturated spots.

Step 4: An interior French drain

The industry-standard fix for water in a crawl space is an interior French drain. Some newer homes have exterior tile drains and foundation waterproofing, like a basement, which help a lot. But over time those tile drains can fill with silt and sediment, and normal settling can open new entry points. That's why a French drain makes sense either as the main fix or as a backup for record rains like Hurricane Helene.

How it's built

A trench is cut in the clay around the full perimeter of the crawl space, about 12–18 inches from the foundation wall and 8–10 inches deep.
Drain pipe with filter media or gravel is laid in the trench.
At the lowest point, a sump pump and basin surrounded by gravel collect the water and pump it away from the foundation.

This isn't a tile drain, since it doesn't sit at the level of the footer. It works as a surface drain for the crawl space. If your crawl space already has severe erosion, a deeper drainage system or foundation waterproofing may be needed.

Common DIY mistakes

Putting the drain right against the foundation wall. Then all the water it catches runs along the foundation, which can cause erosion and settling around the footers.
Using the ditch beside the foundation as a drain. Sometimes the wall was never properly backfilled after the footer was poured, leaving a trench right beside it. During a proper install, that low area is backfilled with clay from the new trench so water doesn't sit there.

Keep your sump pump working

Inspect the pump and basin regularly to make sure the pump runs.
Clean out silt, sediment, and any large pieces of dirt or clay so they don't clog the pump.
Every sump basin should have its own filter sleeve and plenty of gravel around it to protect the pump.

Once the water is under control, see whether your moisture barrier needs replacing. Seeing water under your house? Book a free inspection.