How to deal with a plumbing leak under a foundation

Think you’ve got a leak below your home's foundation? Not sure where to start? Here’s what you should know before you start digging.

A number of things can cause pipes to leak out underneath a building’s foundation: the soil may be shifting, causing the water lines to leak, or deep roots from a nearby tree may be causing problems by poking through drains. Even commercial drain cleaners can wear their way through your pipes. Regardless of the circumstances, tackling a leak underneath your foundation should be done as soon as possible so you don’t cause any further damage.

There are several ways to detect a leak underneath your building’s foundation, including:

• You hear running water
• You spot cracks in your floors and/or walls
• You’ve got unusually warm spots underneath your floor
• You’ve got wet spots on your floor
• There’s a bad smell coming from your floor

If none of these clues help you track down the culprit, you can use equipment such as an electronic amplifier to further your detective work and find the leak.

It’s going to require some heavy duty equipment such as a jack hammer to open up a hole in the concrete slab and access the leak. Start by clearing your furniture out of the way and pulling up any finished flooring or carpet.

If it is a copper line, start by making cuts into the tube that’s leaking and pull the leaky area out of the tube. Install couplings on the edges that are cut and solder a new piece of tubing into place.

Because a leaking drain line could be made of a number of materials and require long sections to be replaced, you will probably need to hire a professional plumber to help. Ask friends and family members if they can recommend one. You’re looking for a licensed plumber who can do slab leak repairs using high-grade materials.

And although a path can be tunnelled from beneath the slab, it might be better to have a professional handle it for you. Fixing a pipe leak under your home's foundation is a big job, but before you start digging, these tips will help you find out where that leak is coming from.