Field guides to hidden leaks

Your water meter counts every drop that passes it, so it is the simplest way to prove a hidden leak exists. This guide walks through the test and what each result points to.

A slab leak is a water line leaking under the concrete floor. The signs are indirect, so it helps to know which ones matter and how to check them before calling a plumber.

In slab homes, the hot water line is often the first to leak. A single valve at the water heater lets you check the hot side yourself.

A sudden jump in your water bill is the most common first clue to a hidden leak, but not every high bill is a leak. Work from the simplest causes to the hardest.

Professional leak detection combines several methods, each narrowing the search. Knowing what each tool does helps you follow a plumber's reasoning and ask good questions.

Supply and drain lines run through interior and exterior walls, and a leak there can go unnoticed until the drywall shows it. Here is how to respond and what repair usually involves.

A stain on a ceiling below a bathroom or kitchen is usually plumbing, but which part matters. A few simple tests separate supply leaks from drain and fixture leaks.

The service line carries water from the city meter to your house. A leak there never shows indoors, but the meter and the yard usually give it away.

Irrigation systems are a frequent hidden source of lost water, and they are easy to overlook because the yard is supposed to be wet. A few checks usually reveal them.

Before suspecting a slab or wall leak, rule out the toilets. An internal toilet leak sends water straight down the drain, so it never leaves a wet spot.

Finding the leak is half the job. The repair choice depends on the pipe's condition, the house's history and what sits on top of the slab.

Pinhole leaks are tiny holes that form as pipe walls thin over time. In older Fullerton homes they are a leading cause of hidden leaks under slabs and inside walls.

This guide does not quote prices. It explains what makes one leak job simple and another involved, so you can understand and compare written estimates.

A licensed contractor and the right permit protect you if something goes wrong. Here is how to check a license and what to ask about permits, without guessing at city rules.

Whether or not your policy covers a hidden leak, good records make the conversation easier. Start documenting the moment you suspect a leak.

Fixing the pipe stops new water, but the water that already escaped is still in walls, floors and soil. Here is what to do in the days after a hidden leak repair.