It's 11:47 PM. A sound of running water. You flick the lights on. The basement is taking water. Before you even dial (514) 655-6560, there are seven moves that, done in five minutes, can save your floor, your insurance claim, and your night.
This guide assumes you're in Montreal or Lanaudière, it's late, and a plumber is on the way. It doesn't replace professional intervention — it limits damage before we arrive.
1. Shut off the water at the source (30 seconds)
Every dwelling has a main shut-off valve. In a Plateau triplex, it's usually in the basement near the municipal water entry. In a condo, check under the kitchen sink or in the shared mechanical room. In Rosemont and Mile End flats, it's often in a small panel behind the bathroom vanity.
Turn it clockwise until it stops. If the valve is rusted or seized, do not force it — you risk breaking the valve body and making things worse. Move to the next step instead.
2. Cut power to the water heater and pump (if present)
If the leak is coming from the water heater, shut off its breaker at the electrical panel and its cold-water supply valve (generally the right-side pipe at the top). A sump pump should be unplugged if it risks getting submerged — its motor isn't built to stay in water.
3. Document before you clean
Three timestamped photos, from three angles. If your insurer asks about the "moment of loss," you'll have it. Never photograph after cleaning — those photos carry less weight with adjusters. Include a shot showing visible water, one of the source, and one wide shot showing the damage zone.
4. Lift or evacuate the furniture
Baseboards, rugs, cardboard boxes, anything that absorbs water — get it up. A wet mattress is a lost mattress; drag it to the hallway if you can. Wood furniture with legs: put plastic under each foot to stop wicking. Electronics on a floor: unplug, elevate, priority one.
5. Ventilate — immediately
Humidity inside a wall takes roughly 48 hours to become mold. Open the windows. Run a fan if you have one. A chilly April living room beats a wall you have to demo in June.
6. If it's a sewer backup, don't touch it
Water coming out of a drain rather than from a pipe is probably a sewer backup. That water contains pathogens — gloves, boots, not bare hands. If you don't have a backwater valve, this is the time to talk to your plumber about installing one. Montreal's PRVHM grant reimburses up to $2,200.
7. Call Plomberie PSF
(514) 655-6560. We answer 24/7 — Thanksgiving at 3:12 AM included. Have three pieces of information ready: your address, the approximate source of the leak, and whether the water is still active. A CMMTQ-certified plumber is at your door in under an hour, with equipment on board.
What you pay at night
An emergency call between 9 PM and 7 AM carries a night surcharge — that's standard in the industry and required to comply with night-shift hourly rates. We tell you the figure before walking in. No work starts without your written approval.
When emergency becomes renovation
Sometimes the leak reveals an aging system (corroded copper, cracked cast-iron drain, an end-of-life water heater). A camera inspection then helps decide whether a repair holds or if you need to plan a bathroom or pipe renovation. Our team gives you a clear diagnosis — not an upsell.
Summary — keep this in your phone
- Shut off water (main valve, clockwise)
- Cut power if relevant (water heater, pump)
- Photograph before cleaning
- Lift furniture, ventilate
- Call (514) 655-6560
Plomberie PSF is a CMMTQ member serving Greater Montreal and Lanaudière, on call 24/7. Over ten years of listening to night emergencies, one rule: your night comes first. For non-urgent questions or to book a scheduled visit, use our contact form.