Finding a Hidden Water Leak in Your Christchurch Home

Signs you might have a hidden leak

• A water bill that's noticeably higher with no change in household use
• The water meter dial still turning with every tap in the house off
• A warm patch on the floor, often over an under-slab hot water line
• Damp or discoloured gib, or a musty smell in one part of the house
• The hot water cylinder running more than usual, or the toby humming when nothing is on

The meter test

This is the first thing we do, and you can try it yourself. Turn off every tap and appliance that uses water, then check the little leak indicator dial on the water meter. If it's still moving after everything is off, water is escaping somewhere between the meter and your fixtures.

We then isolate sections of the house, starting with the toby and internal isolating valves, to narrow down whether the leak is in the supply line to the house, under the slab, or within a specific wall or room.

Acoustic leak detection

Pressurised water escaping through a small hole makes a distinct sound that travels through pipe and concrete. We use listening equipment to pick that sound up at the surface, moving along the suspected pipe run until the noise peaks, which usually pinpoints the leak within a small area rather than guessing across an entire slab.

Thermal imaging

A thermal camera picks up temperature differences at the surface. A leaking hot water pipe under a slab often shows as a warm patch on the floor; a cold water leak can show as a cooler patch, particularly noticeable on tiled or concrete floors. It's a useful second check alongside acoustic detection, especially where slab thickness or floor covering makes sound harder to read.

Common places leaks hide in Christchurch homes

• Under-slab hot and cold water pipe runs in homes built before pipe was routed through the ceiling space
• Joints in old galvanised steel pipework, especially in homes over 40 years old
• External tap and irrigation lines running underground to the garden
• Pipe joints stressed by ground movement from the earthquakes
• Shower and bath waste connections leaking slowly into the floor structure

Once we've found it

We'll explain exactly where the leak is and what's involved in the repair before starting. Depending on location that might mean a small floor or wall opening to access the pipe, or in some cases rerouting the pipe through an accessible space instead of chasing it out of the slab, which is often less disruptive.

Frequently asked questions