Smoke testing · Greater Montréal

Find the hidden source of sewer odours — without opening walls.

We introduce controlled diagnostic smoke into your drain and vent system. If there is a crack, broken joint or failed seal, smoke follows the same path as the odour and shows us exactly where the problem is.

Non-destructive · Controlled test smoke · Clear next steps

  • Pinpoints cracks, broken joints and failed seals
  • Ideal for recurring sewer smells, drain flies and rodent entry
  • Tests the connected drain and vent system at low pressure
  • No demolition just to search for the leak
Technician using a smoke test machine to reveal a leaking drain vent joint in a Montréal basement
Smoke shows the leak
Visible proof, not a guess
No demolition
Test first, repair second
When a smoke test makes sense

The clues are real. The opening is just hidden.

If the symptom keeps returning and a normal inspection has not found the source, smoke can reveal the path that sewer gas and pests are already using.

Sewer smell with no backupThe drains flow, but the odour returns near a wall, ceiling, mechanical room or fixture.
Drain flies keep coming backCleaning the visible drain helps briefly, but flies return because the hidden breeding path remains open.
Rodents or insects near plumbingA broken line or unsealed opening can connect the drainage system to the building interior.
Odours after a renovationA loose cap, dry trap, failed toilet seal or disturbed vent joint may be the real cause.
Suspected crack behind a wallSmoke can emerge at the defect so repairs target the right place instead of opening everything.
The camera looked clearA camera sees inside the pipe. Smoke finds air leaks outside its field of view.
How smoke testing works

One controlled test. A visible answer.

We prepare the system, introduce diagnostic smoke at low pressure, then trace every unexpected plume back to its source.

01

Inspect and prepare

We review where and when the symptom appears, identify safe access, protect the work area and control approved openings.

02

Introduce test smoke

A professional blower sends controlled diagnostic smoke through the connected drain and vent system.

03

Trace the escape

We inspect fixtures, cleanouts, joints, walls, ceilings and exterior vent routes for smoke appearing where it should not.

04

Mark the leak and plan

Every visible defect is documented and explained, with practical repair priorities before anything is opened or replaced.

What is included

A system-wide diagnosis — not a fog machine and a guess.

The goal is a clear answer: where the system is open, what that opening explains, and what should happen next.

Professional smoke equipment

Purpose-built blower, sealed connection and controlled pressure for a credible test.

Full route inspection

We follow the connected system through fixtures, cleanouts, visible piping and vent routes.

Leak-point marking

Unexpected smoke is traced and marked so the repair starts in the right place.

Photo documentation

Visible findings are documented so you can understand and share the result.

Repair priorities

We separate urgent leak paths from lower-priority maintenance and explain the options.

Clear same-visit findings

You leave the visit knowing what appeared, where it appeared and the logical next step.

Free quote

Tell us what you are noticing.

A quick phone diagnosis helps us understand the building, symptoms and likely test scope. Your job-specific flat rate is confirmed before work begins.

Request a plumbing smoke test

Tell us where the smell, flies or pest activity appears and when it is strongest.

We call within 10 min · No spam · Free phone diagnosis

or
Call (514) 779-7262

Request sent!

We will call you within 10 minutes to review the symptoms and next available appointment.

(514) 779-7262
Why Drains ML

Find the opening before planning the repair.

Purpose-built equipmentControlled diagnostic smoke and a sealed blower connection — not an improvised test.
Non-destructive first stepWe use the symptom to find the opening before recommending demolition.
Honest next stepsWe explain what the smoke proved, what it did not prove and which repair makes sense.
Local building knowledgeWe understand older Montréal drain stacks, renovations and mixed piping systems.
FAQ · Plumbing smoke testing

Answers before you call.

What can a plumbing smoke test find?+

Cracked drain or vent pipes, loose fittings, failed seals, open cleanouts and other paths that let sewer gas, drain flies or rodents enter the building.

Is plumbing test smoke safe?+

We use purpose-made diagnostic smoke, not fire. The technician controls the test area and ventilates it afterward. Tell us before the visit about respiratory sensitivities, pets or anyone who may need extra precautions.

Will the test damage walls or pipes?+

No. The system is tested at low pressure. Smoke simply escapes through openings that already exist, so we can identify where a targeted repair may be needed.

When is smoke testing better than a camera?+

A camera shows the inside of an accessible pipe. Smoke checks the connected drain and vent system for air leaks outside the camera's field of view. The two tests are often complementary.

Why do sewer smells, drain flies or rodents point to a leak?+

Cracks, open fittings and failed seals create a path between the drainage system and the living space. Diagnostic smoke follows that same path and makes the opening visible.

Stop tracing the smell. Trace the opening.

Book a plumbing smoke test in Greater Montréal.

Tell us where the sewer odour, flies or pest activity appears. We will help determine whether smoke testing is the right next step and confirm the price before work begins.

(514) 779‑7262

24/7 response · Real technicians · Clear findings

Call now — free quote