What a slab leak is
A slab leak is a leak in a water line that runs under or through the concrete slab a house sits on. In Las Vegas almost every house sits on a slab. Caliche, a hard cemented layer under the surface, is the main reason valley homes rarely have basements. So when a line under the floor starts to leak, the water has nowhere obvious to go.
Why they are hard to spot here
Local plumbers report that dry desert soil soaks up leaking water, so a slab leak can run for a long time without a wet spot. Instead of a puddle you get small clues in other places. That is why a list of signs matters more here than in places with wetter ground.
The signs, from most to least obvious
- A warm or hot spot on the floor. Common when the leak is on a hot water line. Bare feet notice it first.
- A higher water bill with no change in how you use water.
- Running water sounds when nothing is on.
- Flooring changes. Lifting tile edges, swelling laminate, damp carpet near an inside wall.
- Baseboard swelling or paint bubbling at the bottom of a wall.
- A musty smell that does not go away.
- Low water pressure at some fixtures.
- A leak notice from the water district.
The meter check, step by step
The Las Vegas Valley Water District describes this check. It takes five minutes.
Turn everything off
Faucets, ice maker, irrigation, softener regeneration, pool fill.
Watch the triangle
Find the red or white flow indicator triangle on your water meter. If it moves, water is going somewhere.
Shut the house main
Usually in the front yard near the sewer riser cap, in the garage or at a manifold.
Watch again
If the triangle still moves with the house shut off, the leak is most likely underground between the shutoff and the meter. If it stops, the leak is on the house side, which is where slab leaks live.
The district also says its advanced meters let it contact account holders when it sees continuous flow for at least three days. If you get that notice, take it seriously.
High bill or slab leak?
A running toilet is the first thing to rule out. The water district says more than 20 percent of gravity flush toilets leak. Irrigation is the second, and the district notes anti siphon valves should be tested once a year. If the toilets and irrigation are fine and the meter still moves with all water off inside, call a leak detection plumber.
What happens after the plumber finds it
The plumber either repairs the line through the slab or reroutes it through the walls or attic. Then the water damage gets handled. Flooring that traps water against the slab often comes up. Baseboards and the bottom of nearby drywall get read and dried or replaced. Concrete is a dense material and dries slowly, so equipment may run longer than on a normal leak.
Does insurance cover a slab leak?
Policies differ. Many treat the pipe repair, the cost of getting through the slab and the resulting water damage as separate items. Sudden discharge of water is a covered peril on most homeowners forms, and long term seepage often is not. Read the exact wording and photograph everything.