Is it Bad If There's Water in My Crawl Space? 3 Reasons to Worry

Water leaking into the crawl space is a problem you shouldn’t ignore. Find out why and what you can do to fix it.

Flooding and leaks frequently cause standing water and moisture problems in crawl spaces. Puddles can form on a vapor barrier if the liner is installed incorrectly.

Water in the crawl space is a widespread problem for homes with this type of foundation. It may be caused by a storm, plumbing leak, or drainage issue. But whether it’s the first time you’ve noticed water or a recurring problem, you should never ignore a water leak in the crawl space. This standing water can erode a home’s foundation, rot the wooden structural beams and joists, and create mold and mildew issues that impact the air quality throughout the house.

Why do crawl spaces get wet?

Many crawl spaces have dirt floors and are prone to water intrusion and moisture problems, especially in regions with particularly wet or humid climates. Crawl spaces often provide easy access to some of the home’s plumbing, but this can lead to water condensing on pipes or water leaking into the crawl space when a pipe or plumbing fixture fails. Another potential source of water leaking into the crawl space is the surrounding soil. Overflowing gutters, faulty downspouts, or excess groundwater from heavy rain or melting snow or ice can saturate the soil around the foundation. Finally, a sump pump in the crawl space can cause flooding if it fails or malfunctions.

Why is a wet crawl space a problem?

These are the three primary reasons you need to find the source of the issue and take appropriate steps to prevent future flooding or water leaks.

1. Water in the crawl space can sit there for months or years

   Unless there’s a reason to go into the crawl space, including installing or fixing pipes or electrical wiring, it’s usually not an area you visit frequently. Because of this, water leaks or flooding can go undetected for months or even years. Worse, standing water under the house can damage the foundation, rot wooden beams and joists, and cause mold and mildew, contributing to unhealthy air inside the home. Even if you have a vapor barrier in your crawl space, the water will sit on top of the liner until it evaporates.

   What to Do: The best way to get rid of standing water under the house depends on whether you’ve got a few puddles or a crawl space full of water. But water in the crawl space won’t go away on its own. Removing standing water from the crawl space usually involves using a pump, a wet/dry shop vac, powerful fans, and a dehumidifier. A qualified restoration or remediation contractor should address severe flooding, water damage, or mold. Once the crawl space is dry, you’ll need to decide how to keep water and humidity out of your crawl space. Effective crawl space waterproofing and moisture control solutions include installing a sump pump, adding a vapor barrier, and fixing the grading around your house so that water flows away from it.

2. Moisture can cause severe mold and rot issues

   Puddles of water in the crawl space are a problem, but you also have to worry about humidity and moisture in the crawl space. Moisture can cause severe mold and mildew growth and rot. These problems can negatively impact your home’s indoor air quality. And because damp air takes more energy to heat or cool, a moisture problem in the crawl space can contribute to higher energy bills. Finally, humid environments, including crawl spaces, attract termites, rodents, snakes, and other pests. They can damage the foundation, insulation, wires, and air ducts.

   What to Do: Prevent mold, mildew, and rot by addressing crawl space humidity.  Installing a vapor barrier, a specially-designed plastic liner, prevents the movement of soil vapors into the crawl space. Consider crawl space encapsulation if you plan to use the crawl space for storage. This process involves using a vapor barrier and sealing all openings and vents to create a conditioned space - an area that’s heated and cooled with the rest of the home. You’ll reduce condensation, mold growth, dust mites, energy loss from air ducts, and drafts by conditioning the crawl space. Basement Systems offers one of the most complete crawl space encapsulation systems on the market.

   A dehumidifier in the crawl space can reduce crawl space moisture. The SaniDry Sedona dehumidifier includes automatic humidity control. The moisture from the air is automatically drained to a sump pump or condensate pump.

3. There’s a risk of recurring flooding or leaks in the crawl space

   It’s unlikely that the water in your crawl space will be a one-time event. There are several possible sources of flooding or leaks. Whether from surface water, groundwater, or a plumbing problem, the issue won't disappear unless you do something about it. Gutters can fill up with leaves, dirt, and other debris and become clogged. When this happens, rainwater or melting snow or ice builds up in the gutter until it flows over the edge. If the ground slopes toward your house, water will naturally pool around the foundation and can seep into the crawl space.

   

   A good crawl space sump pump is invaluable for protecting your home against flooding.

   What to Do: Minor issues with grading can be fixed with DIY landscaping to slope the yard away from your home’s foundation. But major drainage issues should be dealt with by a professional contractor.

   Installing a sump pump is the first line of defense for crawl spaces with recurring flooding or those in flood-prone areas. The sump pump automatically turns on when the water level reaches a certain point and pumps the water out of the crawl space to prevent flooding. A high-quality sump pump system with a battery backup pump can help avoid major issues that can cause sump pump failure. Choose a sump pump with a sturdy sump liner, an airtight lid, and a reliable pump. Basement Systems’ SmartSump System offers all of these features and is designed specifically for crawl space water removal.

If you have a crawl space that leaks when it rains - even if it’s only sometimes - finding and fixing the standing water or moisture problem should be a priority. A dry crawl space is less likely to develop mold and rot issues, and homes with dry crawl spaces also have better air quality and lower energy costs.

Experienced crawl space waterproofing contractors can prevent future flooding and keep crawl spaces dry using effective waterproofing and humidity control products and methods. Take the first step in fixing your wet crawl space by getting a free crawl space evaluation from a local trusted professional in the Basement Systems network.

Updated: September 27, 2022