Sewer gas, traps and plumbing vents

Diagnose odour through trap seals, venting, seldom-used drains, cleanouts and sumps instead of masking the smell.

VERT / GREEN

Identify seldom-used fixtures/drains and document where odour appears.

JAUNE / YELLOW

A lost trap seal, disturbed venting or non-airtight cover can allow gases indoors.

ROUGE / RED

Persistent strong odour, open drainage system, unsealed sump or gas-related symptoms: ventilate and obtain correction.

Interactive triage

Helps choose the next step; it does not replace design, permits or professional diagnosis.

Seldom-used drain
Check trap seal and why it dries out before using chemicals. Plumbing vent altered
Have venting checked; plumbing vents must not serve other systems. Sump cover not airtight
Correct sealing/venting for the sump function. Odour localized and cause documented
Record the correction and monitor recurrence.

Useful tools and data

Drain/trap/vent map
Odour log
Cleanout visual inspection

What the professional checks

Test trap seal/venting
Check drainage pressures
Confirm sump/vent compliance

Official sources

Checked 2026-08-22.

Related path

Continue with the right tools

These links connect this page to the next useful checks and decisions without repeating the full content.

Start from a symptomOrganize plausible causes, observations, urgency and the right professional.Open →Track water useCompare meter readings and flag unusual changes.Open →Review water resilienceConnect flooding, drainage and future events to building adaptations.Open →Score home resiliencePrioritize water, outages, fire, climate, health and records.Open →Plan site, drainage and utilitiesCoordinate access, water, sewer, wells, septic, grading and site constraints.Open →

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Systems to check before closing the work

This section connects envelope, air, fire, structure, water and code instead of treating each project in isolation.

Renovation dependenciesPlumbing pressure and systemHidden services before drillingCode versions

Explore: Remaining system checks not to miss

Remaining system checks not to miss

This section covers issues that can block a project, cause a loss or become expensive once concealed.

Before closing wallsPrivate sewer/water servicePost-renovation commissioningCodes + climate by province

Explore: Specialized systems to cross-check

Specialized systems to cross-check

This section completes gas, soil, water, fire, climate and structural interfaces.

Gas and combustionIrrigation and backflow

Explore: Edge systems to integrate into the project

Edge systems to integrate into the project

This section covers interfaces that become important when multiple home systems interact.

Pipe freeze protectionDrain-water heat recovery

Explore: Often-overlooked service interfaces

Often-overlooked service interfaces

This section connects systems that cross utility, plumbing, HVAC, envelope and metering boundaries.

Domestic hot-water recirculationWater pressure, PRV and thermal expansion

Explore: Finish and service details to verify

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This section connects small details that become costly once finishes are closed.

Kitchen island/peninsula services and supportPlumbing cleanouts and service access

Explore: Household safety and compliance details

Household safety and compliance details

This section connects smaller risks that often fall between finishes, appliances, plumbing and local code.

Floor drain trap seals and primers

Explore: Commissioning and everyday safety

Commissioning and everyday safety

This section helps verify systems after work and document the values that make a home safer to operate.

Gas-to-induction cooking conversionPlumbing vents: frost, snow and roof termination

Explore: Post-disaster and legacy systems

Post-disaster and legacy systems

This section connects contamination, storm damage, legacy materials and recommissioning before rebuilding.

Sewage backup: contamination and recoveryStorm/tree impact: structure, re-entry and stabilization

Explore: V47 interfaces not to miss

V47 interfaces not to miss

These details are small on a drawing but can control water, structure or durability.

Joist notches/holesBuilding trapCast-iron stack