WATER LEAK DETECTION — FIND IT BEFORE WE CUT DRYWALL

A visible leak is easy. A hidden leak — one behind drywall, under a slab, inside a ceiling cavity, or underground between the meter and the house — is a different animal. You know something is wrong (spiking water bill, mildew smell, warm spot on the floor, sagging drywall) but you can't see the source. Traditional leak detection meant guessing, cutting drywall in a likely spot, and opening holes until you got lucky. That's not how we work.

Our techs roll with professional-grade leak detection equipment — acoustic ground microphones that pick up the sound of pressurized water escaping, line tracers that map supply pipe paths through walls and slabs, and pressure-isolation testing that narrows the leak to a single run before we open anything. Most hidden leaks get located within an inch of their actual position in 30-60 minutes. We open one small access point instead of five drywall holes.

When you need leak detection (not just a repair)

1. Water bill spiked without explanation — sudden jump of 20%+ with no change in usage usually means a hidden leak
2. Warm spot on a concrete slab floor — classic slab leak signature, hot water line under the concrete
3. Wet or discolored drywall, ceiling stain — leak inside a wall or ceiling cavity
4. Mildew smell with no visible moisture — slow leak soaking wood and insulation behind a wall
5. Sound of running water when nothing is on — pressurized leak, often in a wall or slab
6. Foundation cracks or settling — long-term slab leak washing soil out from under the house
7. Sinkhole or wet spot in the yard — main water line leak between meter and house
8. Pool or hot tub losing water — plumbing leak in the deck plumbing or equipment lines

The tools and how they work

Acoustic detection — a geophone or ground microphone that picks up the high-frequency sound of pressurized water escaping a pipe. Exceptionally useful on slab leaks, underground main line breaks, and pressurized line leaks inside walls. We can usually pinpoint the leak within 6-12 inches on a typical slab.

Line tracing — when we know water is leaking somewhere on the supply side but not sure which pipe run, we pressurize and trace the line path with a transmitter so we know exactly where the pipe goes behind drywall or under concrete. Cuts the access opening size dramatically.

Pressure-isolation testing — we shut the water heater and individual branches down one at a time and watch the meter. That tells us whether the leak is on the hot side or the cold side, and which run it's on, before we bring out the microphone.

Dye and tracer gas — for drain leaks (not supply leaks), we can run a dye or tracer gas through the drain and detect where it's exiting through walls or floors.

What Mark Johnson & Sons does differently

We find the leak first. We don't start cutting drywall until we've located the source to within a few inches. The detection fee is flat-rate, set by how involved the search is — and it's waived if you move forward with the repair with us. Most customers end up paying just the repair price, because finding the leak and fixing it are billed together.

Written report with photos of the acoustic and line-tracing findings, a diagram of where the leak is, and a repair quote — all on the spot. Critical for insurance claims where you need to demonstrate the leak was sudden vs. long-term seepage.