Finding Slab Leaks In Residential Homes

Posted on: 5 February 2019

If your last water bill was much higher then expected, then it's possible your home has a plumbing leak inside of its concrete slab foundation. While a slab leak is generally a problem requiring repair by a licensed plumbing contractor, there are many things you can do to determine if a slab leak is causing the increase in your utility bill, including:

Look Around the Exterior of Your House for Puddles or Signs of Moisture

Often, when a pipe is leaking near the surface of a slab foundation and exterior wall, water will pool on the surface directly above it. By walking around the perimeter of your home's foundation, you may be able to find an area with water where you wouldn't otherwise expect it to be.

For example, if there is a puddle on your landscaping near the foundation but it's been sunny outside and there are no garden hoses, dog water bowls, or air conditioning units in the area that could have left behind the water, then a slab leak should be suspected.

Inspect the Interior Walls and Floors for Water or Heat

If you didn't see any signs of water outdoors, then walk around your home's interior and look at all of the walls, cabinets, and floors. You are looking for standing water, spongy floors or walls, or even heat.

Typically, slab leaks are caused by hot water lines because hot water tends to corrode plumbing pipes much more than cold water. When a hot water line is leaking in a slab, it heats up the concrete and thus the floor above it. For this reason, if you feel a warm area on a floor and it isn't near a heater vent or other heat source, then a slab leak should be suspected.

Check the Hot Water Heater

Since most slab leaks are caused by hot water lines, the hot water heater can often signal a leak. Your hot water should only run for a few minutes at a time. If you check the water heater periodically throughout the day and it always seems to be running, then hot water is leaking.

Check the Utility Company's Water Meter

Finally, if your home has a leak where the water line is leaking near the bottom of the slab, then you may not see any signs of water on the surface. However, since the water is constantly leaking out, you can "see" it by turning off all of the water in your home and watching your utility company's water meter in the manhole out near the street. If the water is off and the meter is moving, then water is leaking.