How to Find the Cause of Water Seepage

If you think you have water seepage in your basement, how can you tell exactly where its coming from? Howard Shachter, vice president of U.S. Waterproofing, tells of some common causes and the secret key to detect exactly what is responsible for the water seepage in your basement.

The best first step is to look for obvious water markings inside of your basement. Telltale clues include water-stained carpets and floors, loose tiles, mold at bottom of the wall, and a weathered and decayed look to your drywall and/or wood paneling. Most seepage situations are not one-time occurrences. They happen and then happen again perhaps even a year later when the weather conditions are right – be they heavy rain or melting snow.

You can easily tell if your seepage is coming from your mortar joint just from going outside and looking at your land grading. If your foundation is below the soil surface, that is almost definitely the culprit. The water is permeating through the mortar or brick and coming in over the top of the foundation and into your basement.

Another common cause of seepage can be foundation cracks that can occur over time within the concrete walls of your foundation as it settles and cures. When the cracks are large enough, they will allow water to slowly trickle in.

Finally, another usual suspect is water permeating in from below at the cove joint. This is the spot where the concrete of the floor meets with the concrete of the wall. This spot is sensitive as builders often pour the concrete for each of these pieces at different times during the construction process, leaving nothing more than what is essentially a sealed crack in the concrete where the floor meets the wall.

Other guilty culprits can be pipes within the foundation walls which are not sealed properly or window wells that collect water due to faulty drainage systems.

Luckily, there is a pretty simple test that we or anyone else can do to find out exactly where the seepage is coming from even if your basement is finished so you cannot see the naked concrete. We simply lay down a garden hose outside the house and turn it on. Then we wait for the water to start seeping into the basement. If the water is coming in over the top of the foundation – through the mortar joints - it will come in within 5 minutes. If it takes longer, perhaps 15 minutes, to start seeping, it is probably a foundation crack. And if the seepage starts in 20 minutes or half an hour then, the likely culprit is a cove joint at bottom. The time it takes for the water to work its way down the earth to the bottom of the foundation is how you can usually tell where exactly your problem lies so you can solve it.