As an Amazon Associate we earn from qualifying purchases. Learn More.

    Crawl Space Flooding

    Crawl Space

    Your crawl space is likely an area in your home that you don't frequently visit. In fact, it's relatively remote. But if water tends to pool under your house it can become a breeding ground for mold. These types of unexpected problems are not only annoying, they can also develop into a much larger problem.

    Mold needs two things to survive: Moisture and darkness, and  crawl spaces provide both of these two requirements.

    Once mold begins to grow it can spread through your home's ventilation system and cause health problems for you and your family. It will also grow on hard surfaces such as ducts and joists. Soft surfaces, like plastic vapor barriers and fiberglass insulation are all prone to mold growth as well.

    Above or Below: Where is the Water Coming From?


    If the water seems to be coming from above ground, it's likely caused by a drain pipe or a leaking water supply pipe. An easy way to check is if you notice the water level increases in the crawl space when water is running inside the house.

    For example, the dishwasher or washing machine is running, a toilet flushes, or someone is taking a shower. If the water level goes up, the problem is likely caused by household plumbing.


    If the water seems to be coming from no where, than there's a good chance that it is seeping up thru the ground or thru the walls of the foundation. 

    Water in Crawl Space: 5 Common Causes

    1 - Landscape Grading

    All houses, new or old, with basements or with crawl spaces, should regularly checked the landscape grading. We recommend doing this during the Spring after the ground thaws. This is a good time to see if the Winter weather washed away any soil.

    Simply walk around the perimeter of your home and look for any areas where the soil has dipped and water is pooling next to the foundation. If you see pooling it's a clear sign there's a problem. Although, other signs may not be so obvious. 

    • The proper slope should be 1 inch for every foot. This will direct the water away from the walls of your foundation. The slope should extend outward for 6-8 feet.

    The fix is as easy as adding soil to the lower areas in order to build them back up to the necessary level. This video will show you how it's done:

    2 - Gutter and Downspout Issues

    When it comes to crawl space leaks and flooding, gutters and downspouts is one of the top causes. During a rain storm the roof collects an amazing amount of water. If the gutters are not cleaned regularly the water has no where to go . . . other than over the side of the gutter. 

    When gutters overflow, large pools of water can develop around your house. This can negatively affect the landscape grading that surrounds your foundation, and the water can eventually seep into your crawl space​. Gutters can only perform their intended purpose if they are kept clean and free of debris.

    However, even if your gutters are clean and collecting water as they should, improperly placed downspouts can be a major issue.​ Water should be directed away from your house to prevent pooling.

    3 - Flower Beds

    We all love beautiful landscaping, but unfortunately flowers and shrubs need to be watered. Sprinkler systems, forgotten hoses that are left running, and sometimes simply over watering, can cause pooling that can eventually find it's way into your crawl space. 

    4 - Broken Water Lines

    Not all crawl space problems originate from outside your house. If you have an unnoticed  broken pipe inside, the water will trickle down and eventually find it's way to your crawl space. 

    Although, this may seem unlikely, it is actually more common that many people realize. Take a visual inventory of your home and look for any obvious wet spots. If you suspect you have a broken pipe, but are unable to locate the source of the leak, call a professional plumber. They'll be able to pinpoint the exact spot and repair it for you. 

    5 - Subterranean Water

    Crawl space leaks can also be caused by situations that are outside of your control. City water lines rupture, torrential storms pass thru,  and the ground water table frequently reacts to these and other situations. 

    In many cases city municipalities will need to diagnose and​ resolve the situation. If the flood was caused by a broken pipe, it is normally the cities responsibly to fix the pipe if the problem occurred before your water hook-up. However, if the problem was between the water hook-up and your home, you'll likely be responsible for it's repair. 

    Subterranean water can be caused by a number of issues:

    • ​Clogged or damaged underground drains that were designed to carry water away from your house. 
    • The drainage system is overwhelmed by a heavy storm and the overflow water is absorbed by the soil. 
    • Improper drainage can create a situation where the walls of the foundation will not allow the water pass. The walls literally create a dam preventing the water from properly draining.