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How to Waterproof a Basement

Feb 1, 2020 | Services

Water damage is not always obvious. Moisture in your basement is sometimes insidious, slowly damaging the structure of your home. Whether you discover several inches of standing water or suspect condensation, waterproofing your basement is the only solution. Here is how to waterproof a basement:

  • Identify Signs of Water Damage
  • Identify and Treat Condensation
  • Identify and Treat Runoff
  • Identify and Treat Groundwater Swelling

Identify Signs Of Water Damage

Before you fix the problem, you must identify it. There are three common causes for wet basements:

  • Condensation
  • Runoff
  • Groundwater swelling

Each type has its own telltale signs to look out for. In general, a musty smell is an indicator of moisture in your basement. Don’t ignore this odor. Investigate your building for the other signs of water damage.

Identifying And Treating Condensation

Condensation is the result of warm, moisture-laden air coming into contact with cooler foundation walls. This creates wet spots on the floor and walls and leads to structural problems down the road, not to mention unpleasant smells.

There is a simple way to determine if the moisture is the result of condensation or a leak. All you need are tape and plastic wrap. Choose a damp spot and cover it with the plastic wrap. Secure the wrap with tape all around the edges. If moisture appears on the inside of the plastic wrap (the side against the wall), there is a leak. If it appears on the outside, there is a condensation problem.

Condensation is the easiest wet basement issue to fix. Installing a decent dehumidifier usually takes care of the issue.

Identifying And Treating Runoff

Evidence of runoff is most common in the spring. Melting snow and rainwater are the culprits, along with improper drainage around your foundation. The runoff water forces its way through gaps and cracks in your walls and foundation due to hydrostatic pressure.

This results in mold and algae that are not only signs of a problem but potentially hazardous to your health. Fixing a runoff issue takes a little more muscle than installing a dehumidifier. Sometimes calling a landscaping company is the best solution.

Prevent runoff from getting into your foundation and pooling around your house by sloping the ground around your home away from the walls. This requires a significant amount of dirt. The ideal slope drops at least an inch every twelve horizontal inches. While you are at it, check your downspouts to make sure they are not pooling and adding to the problem.


Identifying And Treating Groundwater Swelling

Groundwater swelling is the trickiest basement issue to resolve. It is the result of an overflowing water table. When the water table reaches its capacity, the soil is no longer able to drain, and your basement floods.

If you have a groundwater swelling problem, you might notice that your basement is wet after a storm. You might even see water actively bubbling up from between the wall and floor joints.

Treatment for groundwater swelling depends on your budget and your yard. Clay soil is a common cause of poor drainage, as the small and closely packed clay particles inhibit water from draining quickly through the soil.

The first option for dealing with rainwater is working with the gradient of your yard. A landscaping professional is a good resource for concerned homeowners. The second option also requires professional assistance and requires installing an underground drainage system.

The third option is expensive but equally effective. Raising the ground level gives the water more space to drain, sparing your basement from flooding. This requires a lot of material and manpower and is not a good choice for a DIY project.

Other Waterproofing Methods For Basements

There are other options for dealing with wet basements. After you identify the problem and patch the obvious cracks, consider applying a concrete sealer or fitting a polyethylene membrane. Installing a sump pump is another way to get rid of standing water and the water that collects behind your newly installed polyethylene membrane.

Don’t put off addressing a wet basement. Pooling water poses health threats from mold and algae and damages your foundation, along with anything stored in your basement. Identify the problem, come up with a solution, and start waterproofing your basement by contacting us today.

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About the Author

Matt Johnson grew up in a family of landscapers and gardeners as the grandson of Raymond Johnson (Founder, 1933, Johnson's Florist and Garden Center) and son of James and Carol Johnson (Founders, 1960, Johnson's Landscaping Service, Inc.). Since 2007, he has led Johnson's Landscaping Service with his brother, Charlie.  Matt and his wife Jaime live in Petworth in Northwest DC with their 3 sons and 2 big dogs.

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