Slab Leaks at Stores, Offices and Apartment Buildings

Something is off with the floor. A warm spot on tile, carpet that is damp near a wall, flooring that has started to lift, or the sound of running water when nothing is on. Often the first sign is the water bill, up sharply with no visible leak.

A slab leak is a leak in a water supply line that runs under or through the concrete slab. Many commercial buildings and apartment communities in the Phoenix area are built on slabs, and in those the lines that feed restrooms, kitchens and water heaters are buried below the floor. Over time, corrosion, ground movement and pressure can wear a hole in one of them.

We narrow it down before we open anything. First we confirm the leak is on the building's side: with everything off, a meter that keeps moving means water is escaping somewhere.

Then we isolate sections. We shut off valves one branch at a time to see which line is losing water, and we pressure-test the isolated line to confirm it can't hold. When the leak is in a branch, that tells us which part of the building to open. We narrow it to a section, and then we expose the pipe at the likely spot to confirm.

It's a process of elimination, and it works best when you can tell us how the building was plumbed and what changed recently.

Once we know which line has failed, there are usually two options. We can open the concrete at the leak and repair or replace that section, or we can abandon the buried line and run a new one overhead or through a wall. Rerouting is worth considering when a line has failed more than once or runs under areas that are hard to open.

Either way, it goes into a written proposal and you approve it before work starts. If the concrete is opened, we restore the opening, and finish work like flooring or tile can be handed to another trade. We'll tell you where our work ends and where another trade begins.

Shut off the water to the affected branch if you know where the valve is. If water is reaching tenants' units, electrical equipment or inventory, shut off the main and call us right away. We offer 24/7 emergency service.

Have the last several water bills ready and any plans that show where lines run. Tell us how to get in, including lockbox, gate code or escort, and who authorizes work. For a store or office, tell us whether the lease puts the line on you or the landlord, and check whether your business insurance covers water damage.

The signs are the same: a warm spot on the floor, running water sounds, a high bill. Do a meter check with everything off. If the meter moves, call us.