Water in Crawl Space: 5 Causes and How to Fix Them

Crawl Space

Water in crawl spaces can be a bigger problem than you might think. Even though a crawl space is a relatively remote area of the home, water that pools there can cause issues on every floor if mold forms. The two things mold needs to survive are moisture and darkness, both of which can be prevalent in crawl space that has a leak. Mold can spread through the ventilation system, causing health problems and can grow on piers and joists causing structural issues.

Keep reading to learn how water enters your crawl space and the things you can do to prevent it.

Cause 1: Poor Grading on Surrounding Landscape

It cannot be stressed enough how important a slope away from the home is in preventing foundation damage. Essentially, properly sloped grading around your crawl space can help prevent water from entering your home.

The remedy of a poor sloping grade is to build it up. Make sure you have a slope of at least 6-8 inches away from the foundation walls, extending for the first 6-8 feet. This grade should be checked every spring once the ground thaws to see if the winter has washed away or caused any shifting of the structure.

Cause 2: Downspouts and Gutter Issues

One of the most devastating things about water in your crawl space isn't the damage caused, the lack of access, or even the impending health problems – it's the fact that the whole ordeal could have likely easily been prevented. This is because the biggest cause of crawl space leaks in a house is improper downspout aiming or not cleaning out gutters.

Downspouts should be pointed away from the home's foundation and also be accompanied by a 2-foot splash block at the bottom that guides water away. When a home doesn't have a downspout, or has one that is faced at the house, the storms will eventually wash away the grade of your soil and direct water on a bypass into the basement.

Cause 3: Over-Watering Flower Beds

Sometimes water in your crawl space is caused by human error, specifically when a hose is left running near the side of the house or when somebody over-waters their shrubs. Not only can excessive watering cause plants to die, it also creates a water source that many homes aren't equipped to deal with. Make sure your flowerbed is equipped with the proper base layers to prevent water from skipping right past the roots and into the crawl space instead.

Cause 4: Ruptured Water Lines

Crawl space leaks can also originate from inside the home. The thing about water is that it will always trickle down, so even if a pipe has burst somewhere near an upstairs bathroom, it may find a final resting spot in the crawl space.

The easiest way to detect a broken pipe is by taking a visual inventory of the home, looking for obvious wet spots. If you suspect you have a broken pipe but can’t locate the leak call in a plumbing service to help you pinpoint the exact spot of the ruptured or loose pipe connection.

Cause 5: Subterranean Water

Of course sometimes a crawl space leak comes from outside the home, either from a broken city line or water that comes from underground. City municipalities will have to come on site to fix any line problems on their end and there could be a number of things causing subterranean water to form such as:

  • Foundation walls creating a dam that causes surface water to seep underground and eventually find an opening in the crawl space.
  • Underground drains that are designed to carry water away from the home have become damaged, plugged, or have insufficient slope.
  • A torrential storm creates just too much water for your drainage system to handle and causes pools of water that eventually seep deep into the soil.

More Waterproofing Options

There are many ways to waterproof your crawl space. Most of the techniques discussed in the article HERE and they can be applied to crawl spaces as well to help keep them dry.