Some of the most expensive leaks never make a sound. A burst pipe announces itself, but a supply line weeping a few drops a minute behind a dishwasher can run for weeks before anyone sees a stain. By then, the cabinet base has swollen, the subfloor is soft and mould may be growing in a space nobody looks at.

Leak detection with thermal imaging and moisture mapping, which Water Damage Restoration Sherwood Park and similar firms offer, exists largely because of this kind of slow, hidden water. Still, most of these leaks start in a handful of predictable places, and a homeowner who knows where to look can often catch them early.

Appliances that use water

Washing machines

The fill hoses behind a washer are under constant pressure whenever the taps are open, which in most houses is all the time. Rubber hoses can stiffen, bulge and crack with age. Many owners replace them with braided stainless steel hoses, and some turn off the supply valves when leaving for a trip. A drain hose that slips out of its standpipe can also send a full load of water onto the floor, and front-loading machines occasionally leak from a worn door seal.

Dishwashers

A dishwasher’s supply line usually runs under the kitchen sink and along the floor behind the toe kick, out of sight. Leaks from that line, from the drain connection or from a tired door gasket tend to show up as flooring that lifts or darkens in front of the machine, or swelling along the bottom edge of the adjacent cabinets.

Refrigerators with ice makers

Fridges with water dispensers or ice makers are fed by a thin line, often plastic, that runs to a valve behind or below the unit. When the fridge is pushed back into place after cleaning, that line can kink or crack. Because the leak is behind a heavy appliance, it may only become obvious when hardwood or laminate nearby starts to cup.

Water heaters and other sources

Tank water heaters

Steel tanks are lined and protected by an anode rod, but over the years corrosion can still work through, usually at the bottom. A small puddle under the heater or rust-coloured water at the taps are both warning signs. Water dripping from the discharge pipe of the temperature and pressure relief valve is another; that valve opens when pressure or temperature inside the tank gets too high, and a plumber or gas fitter should find out why. A drain pan under the tank, ideally piped to a floor drain, limits the damage if a leak develops. The manufacture date is normally encoded in the serial number on the label, which helps when judging how much life the tank has left.

Furnace humidifiers and condensate lines

Dry prairie winters lead many households to run a humidifier mounted on the furnace. Those units have their own small water line and a drain, and a sticking valve or a clogged drain can drip into the furnace cabinet or onto the utility room floor. High-efficiency furnaces also produce condensate, which runs through a tube to a floor drain or to a small condensate pump. When that pump fails, water can quietly overflow beside the furnace, often in a corner of an unfinished basement where nobody stands for long.

Toilets and vanities

The braided supply line to a toilet and the wax ring that seals it to the floor are both common culprits. A failing wax ring often shows up as a floor that feels slightly soft around the base, or a stain on the ceiling of the room below. Under bathroom and kitchen sinks, slow drips from trap connections and supply valves can soak the cabinet floor for months before the particleboard swells enough to notice.

Beyond checking each of these spots now and then, there is a simple whole-house test. With every tap, appliance and fixture turned off, the water meter should not move. If its dial or display continues to register flow over half an hour or so, water is going somewhere. A musty smell in a cabinet, a water bill that rises for no clear reason, and paint or baseboards that discolour near the floor are other clues worth following up rather than ignoring.