Blocked toilet or drain

A single blocked fixture, a toilet or a sink, is almost always a local clog, an object, paper, or set grease, that a hand or electric auger clears in one visit. When several fixtures back up at the same time, say the ground-floor toilet and the basement floor drain together, the blockage is probably further down in the shared stack, which changes how it gets cleared.

Before the plumber arrives, shut the supply valve to the toilet if it keeps filling and overflowing, and skip any chemical drain opener if an auger is going to go into that pipe afterward: the combination is dangerous for whoever's handling the equipment.

On arrival, a plumber always starts with the fixture that was reported before checking the others, to confirm whether the blockage is local or shared across fixtures. A hand auger is enough for a clog close to the fixture; a longer electric auger comes out as soon as the blockage seems to be further down the stack, which gets confirmed by how much cable goes out before hitting resistance.

A blockage that comes back every few months in the same drain deserves a camera inspection rather than a third clearing: roots in a cast-iron stack, a sagging section of pipe, or not enough slope are common causes in Montreal's older building stock.

In Montreal's older building stock, cast-iron drain stacks lose diameter to internal corrosion over the decades, so flow that moved fine in 1985 sits and backs up today. In a triplex where three units share the same vertical stack, a blockage also shows up differently by floor: the ground-floor unit usually backs up first because it's closest to the low point.

Price depends on the fixture involved (a toilet generally clears faster than a kitchen drain loaded with grease), how much auger length it takes to reach the blockage, and the hour of the call for the after-hours premium. A camera inspection, when the blockage keeps coming back, is added on top of the clearing rather than replacing it.

Before you call, note which fixture is affected and since when, whether more than one fixture is backing up elsewhere in the house at the same time, and whether you've already poured a chemical drain opener down it, something the plumber needs to know before they open the pipe.

When the camera confirms roots or a sagging section in the main line rather than a simple clog, the fix changes scope: a mechanical or hydraulic clearing can work as a short-term fix, but a sagging or badly corroded stack eventually needs a section replaced, work that goes well beyond an emergency clearing and gets scheduled rather than done overnight.

An overflowing toilet keeps rising as long as the tank keeps refilling: closing the supply valve at the wall near the base of the toilet stops the water immediately, often faster than trying to plunge it yourself while the water keeps climbing. A sink or shower that won't drain, by contrast, usually doesn't overflow clean water, but adding more water while checking it, running a tap, flushing elsewhere, just makes the problem worse before the plumber arrives.

Thick or excessive toilet paper, so-called flushable wipes, and grease poured down the kitchen sink remain the most common causes of an avoidable blockage. In a plex where the stack is already narrowed by corrosion, those habits are enough to trigger a blockage that wouldn't cause any trouble in newer plumbing.