Crawl Space Water Damage Prevention Tips

At first, it might not seem like a little water would be a problem. You don’t go in there often; you’re not storing anything in there. Who cares if there is a little water? If moisture in your crawl space isn’t addressed, it can lead to issues that will compound the repair costs. The two main concerns are mold and pests.

According to Angie’s List, moisture in your crawl space can make it a prime breeding ground for mold. Mold and mildew love moisture, even the slightest amount. Wood located in your crawl space gives mold plenty of food to enjoy. If you have vents in the crawl space, mold spores can quickly move from isolation in the area and up to the rooms of your home, where they’ll find a place to set up residence.

Mold can also have adverse effects on your overall health. Breathing in mold spores can cause pulmonary issues and can make controlling illnesses such as asthma more difficult.

Pests can crawl in through the smallest of holes. Many of them are attracted to humid and moist environments, making your crawl space the prime spot for a home base.

Dust mites thrive in this type of environment as well. These microscopic parasites live in plush surfaces, such as bedding, furniture, and carpeting. Their airborne droppings can trigger allergies and asthma.



Snakes, spiders, and mice will also find this environment to their liking and will move to other areas of your home with relative ease. Termites are another pest that might find a home in your moist crawl space and begin damaging your home’s structure.

Constant battles with water in your crawl space may make you consider finding a way to easily remove the water. For this, look at installing a sump pump.

A sump pump is a pump installed below ground in a sump pit. Place the pump where water accumulates or at the lowest point of your crawl space. Putting it in the lowest point helps to keep the spot from flooding.

During dry weather, the sump pump is in standby mode. However, once a heavy rain begins and the groundwater level begins to rise, the pump kicks into action. The excess groundwater fills the pit and activates the pump via a float switch. The pump then removes the water from the hole and keeps it from filling your crawl space.



Sump pumps are an investment to consider. However, they only work in situations where excessive groundwater is a problem. If this is not the case, you may consider other water damage prevention methods.

Installing a drain just below crawl space level is a preventative measure taken by many homeowners. To correctly prevent water from entering your crawl space, you need to cut the trench outside your home’s foundation and below the crawl space. By doing so, the drain will collect the water and divert it from the area entirely.

The most common drains used to keep water from getting inside crawl spaces are French drains. This drain is essentially a trench with a perforated pipe, lined with gravel. The pipe allows collected water to flow away from your home. The gravel also helps to redirect groundwater away from your home.  Your drain trench’s floor should be both flat and evenly sloped to help pull water away.

Some people find it best to install a French drain in the same area as their sewage line. According to thespruce.com, the bottom of your trench needs to be 8 to 24 inches away from the foundation of your home. Trenches located closer can damage the foundation. Depending on your location, it may not be possible to install alongside the sewage line.

Sometimes, the simplest way to keep water out of your crawl space is to repair the issues that allow water in. For those with a drain system already installed, remember you have to perform maintenance on the drain to keep it in working order. French drains can go about 10 years between maintenance cycles, but you need to check them periodically.

Several other problems could contribute to water accumulation.

• Negative Grading: Land near the foundation of your home should slope away from your property. When the ground slopes towards the foundation, negative grading encourages water to drain towards the foundation instead of away.
• Downspout Breaks: Gutters can help prevent rainwater from accumulating too close to your foundation. The downspout funnels precipitation away, but if there is a crack or a break between the gutter and the downspout, water can leak into your crawl space. Periodically check for cracks and fix them.
• Foundation Issues: If you have a crack in your foundation, groundwater can easily penetrate and quickly become a problem. If you continue to see water problems in your crawl space, it may be time to check the foundation. Look for cracks and gaps outside. Thisoldhouse.com notes that you can fix some holes using a bit of epoxy to seal them. If the foundation issues are too significant, it’s best to call in a professional. 
• Leaky Pipes: Foundation issues are not the only way water can get into a crawl space. Leaky pipes are a frequent problem and are easy to diagnose. Check the area where the water is for any signs that there is a leak. If necessary, contact a plumber to correct the issue.
• Ineffective Waterproofing: In the last 30 years, waterproofing foundation has become more commonplace at the time of construction. However, not all waterproofing methods used by contractors are adequate. Materials such as CMU concrete blocks, terra cotta, and brick are more porous than current options, allowing for excess water entrance. You may need to install a sump pump or install a new drain to help compensate.

One of the most effective ways to keep water from seeping into your crawl space is a concrete slab. Under the slab, your contractor would put a thick layer of waterproof plastic. The combination keeps subterranean groundwater from getting into the crawl space.

While this is one of the most effective methods to prevent crawl space water damage, it can be costly. If you are building a new home, you can make it part of the original design which will help with the cost. However, if you are doing it to an existing crawl space, some owners may be cost-prohibited.

By understanding why you don’t water in your crawl space, you can begin to find the best way to keep it out. Using a sump pump, installing a French drain, or repairing issues causing the leak are essential steps to making the area water-free. If possible, add a concrete slab to your crawl space floor to prevent groundwater from seeping into the area.

• https://www.angieslist.com/research/crawl-spaces/
• https://www.thespruce.com/how-to-fix-water-in-crawl-space-1821953
• https://www.thisoldhouse.com/masonry/21016504/fixing-cracks-in-concrete