How often should you check for water leaks under sinks and appliances?

Hidden slow leaks cause mould and rot long before you see them.

A slow leak under a sink or behind a washing machine soaks the cabinet base, the subfloor and eventually the structure. The EPA says water-damaged areas need to be dried within 24 to 48 hours to prevent mould growth, which a leak nobody has noticed never allows. Cover for slow leaks varies between insurers, so do not assume a long-running one is insured.

1. Read the meter with everything off. Turn off every tap and appliance, note the meter reading, wait two hours with no water used, and read it again. The EPA says that if the reading has changed at all, there is probably a leak.
2. Check under every sink. Empty the cabinet and feel the base with your hand. Look for staining, swelling of the chipboard, or a white crust of dried mineral deposit around fittings.
3. Inspect appliance hoses. Look at washing machine and dishwasher hoses for bulges, corrosion at the crimps and any dampness, and replace any that look tired.
4. Look at the water heater. Check the base of the tank, the relief valve discharge pipe, and the connections. Rust or damp at the base of the tank needs a plumber.
5. Check toilets and the base of pans. Feel for damp around the base and look for movement when the pan is rocked gently.
6. Look at ceilings below bathrooms. Yellow or brown staining on a ceiling is water that has been arriving for a while.
7. Check outside taps and any irrigation. Outdoor leaks disappear into the ground and can run unnoticed. The EPA advises checking an in-ground irrigation system each spring before use.

• A water bill higher than usual with no change in habits
• The meter creeping with everything switched off
• Musty smells in a cupboard, particularly under a sink
• Staining, bubbling paint or swollen chipboard
• Warm patches on a floor, which can indicate a hot water leak beneath a slab
• Reduced water pressure with no other explanation

• Only looking where you can already see, rather than emptying cabinets and feeling with your hand
• Ignoring a small drip because it seems trivial: the EPA says a tap dripping once a second can waste more than 3,000 gallons a year
• Not checking appliance hoses, which can fail suddenly
• Dismissing an unexplained bill increase

• Check before leaving the house empty for an extended period, and consider turning the water off entirely
• Homes with a water softener, filtration or irrigation have more fittings and more failure points
• Leak detection devices that shut off the supply automatically are worth considering

If the meter shows a leak but you cannot find it, it may be underground or beneath the slab. That needs professional leak detection rather than more searching.