Detecting a Water Leak in Your Foundation or Slab

foundation-slab-water-leaksA water leak in your home foundation or slab is something that no homeowner wants to face. But how do you tell if you have one? If you are experiencing higher than normal water bills or have noticed foundation movement, you might have a water leak.

How Do You Know if You Have a Foundation or Slab Water Leak?

The leaks below the slab usually come in two forms: sewer leaks and leaks in the water lines. If your water lines are leaking, even a pin gap, you will notice it when your water bill arrives and you can act quickly to repair it. Even the smallest leak can gush over 100,000 gallons in one month! In contrast, a sewer leak can leak for years and no one would be the wiser. Sometimes, a leak can add sufficient water and swell the surrounding soils. This is known as “heaving”. Heaving is caused when the soil expands from a water or sewer leak and raises a building or home. The expanded soil can actually bend the foundation or cause a dome shaped phenomenon. Both of these problems can cause major damage to your home and will create cracked walls and floors. It can also create a place that is damp and prime for toxic mold to grow. A trained eye can spot heaving and make the necessary repairs to avoid even more damage.

How Do you Test for Foundation or Slab Leaks?

There are two simple tests for water lines. First, a pressure gauge is hooked up to a spigot and the spigot is then opened. The gauge will show the pressure at which water is delivered from the street, as long as all water use is stopped beforehand. The next step to test for water leaks in your foundation is to turn off the water meter. If there are no leaks, the pressure on the gauge will stay the same. If the pressure drops, it means there is water escaping from the lines in and underneath the home. If a pressure drop is found, then the taps, toilets and other water outlets will need to be rechecked for drips or slow use. If no drips or slow use are found, then the lines are most likely leaking beneath the house.

If you are checking for a sewer leak, there is also a two part test. First, the sewer line is blocked off with a balloon where it comes out from beneath the foundation. Then the sewer is filled with water. If the water level in the sewer drops, there must be a leak since the sewer is blocked off from the main. Generally if a leak is detected, this test is run a second time to be sure that the first test didn’t result in a “false positive” result.

How Do You Find Foundation or Slab Leaks?

Cameras can detect sewer leaks. They can be pushed down into the sewer lines to see where the leak is coming from. Another way to detect a leak is to isolate or flood individual sections of pipe. In the case of water lines, various listening devices are often used for detecting water line leaks.

If you think you might have a water leak but can not find it, let North County Plumbing help. Call us today!

North County Plumbing has been in the service business since 1970 providing quality plumbing services including leak detection and drain service in northern San Diego County. Our qualified technicians are available 24 hours a day to help with emergency plumbing repair services… with no overtime charges!

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