Once you know you have a leak, you'll need to hire a plumber. But how do plumbers find leaks? Plumbers use moisture meters and determine the area of the wall with the highest moisture levels. Sometimes, leaks are located using infrared cameras, which point out the coolest (and wettest) areas behind the walls.

Water leaks can also be detected by infrared cameras, as wet areas tend to be cooler in temperature. Again, plumbing professionals will usually provide their own camera to locate the leak. Once your plumbers find the location of the leak, they'll get to work fixing it.

Check the water meter to see if the numbers change in the next two or three hours. If the levels change, there's a leak somewhere, most likely underneath the floor. If the bathroom is on a second story, go downstairs and check the room underneath. Look for any signs of a leak – water stains or drops of water.

Symptoms of Water Leakage Sudden Increase in Water Usage, Sounds of Water Running When Nothing Turned On, Damp Patches Occurring on Floors and Walls, Mildew and Mould Low Down on Walls.