Leak Detection

The next step is to take the system apart logically rather than physically. Closing the valve at the water heater tells us whether the loss is on the hot side. Closing fixture stops removes branches from the picture one at a time. Where the piping allows it, we isolate a section and pressure-test it: cap the ends, put it under pressure, and watch whether it holds. A section that holds is not the leak, and ruling things out is most of the work.

Drains need the opposite approach, because a drain is only under load when something runs into it. So we fill and hold fixtures, flood traps, and watch. Toilets get dye in the tank. A shower gets tested in pieces, because water that only appears when the shower runs might be the pan, the drain connection, the mixing valve body inside the wall, or grout letting water past the surface of the tile. Those are four different repairs.

Appliances get their own look. Dishwasher door gaskets, fridge water lines, washing machine hoses and condensate lines all put water on floors that people assume must be a pipe. We rule them out as part of the investigation even though the repair on some belongs to another trade.

Acoustic equipment picks up the noise a pressurized leak makes as water escapes through a small opening. That sound carries through the pipe and the structure, so moving a listening disc across a floor or a wall narrows the loudest point down to a small area. It works well on supply lines under pressure and not at all on a drain that is not running.

Thermal patterns help on hot lines, because a hot water leak warms the material around it and shows as a bloom that has no business being there. Moisture meters map how far the wet area has spread behind a finish, which sounds like it answers the question and does not. Water travels along joists, runs on top of a ceiling sheet, and drops at the first seam it reaches. A stain in the centre of a ceiling is often fed from a leak two or three metres away at the wall.

That is why we trace back to the source instead of cutting at the stain. The cheapest hole is the one in the right place.

Some leaks cannot be confirmed without opening something. The methods above narrow the search to a small area with good confidence, but a fitting inside a wall cavity has to be seen before it can be repaired, and there is no tool that solders a joint through drywall. When we reach that point we tell you before we cut, we cut the smallest access that will do the job, and we put it where it is easiest to close back up.

We also cannot promise the finish goes back the way it was. We are plumbers. We open access, make the repair, and leave the opening clean and square for a drywaller or a restoration contractor. Textured ceilings, plaster in older houses and tile are all specialist work to reinstate. If the damage is significant, call your insurer before repairs begin, because most policies want the claim opened first.

Slab and under-floor leaks are the awkward case. Most Toronto houses have basements rather than slab-on-grade, but slab leaks do turn up in additions, converted garages, condominium units and homes with in-floor radiant heat. Locating one is realistic. Getting to it means breaking concrete, and there are times when abandoning the buried run and repiping overhead is cheaper and less destructive than opening the floor.