Many homeowners across Vancouver, Burnaby, and Coquitlam notice strong smells during late August and early September. The odour often smells like rotten eggs or damp soil. It can come from sinks, floor drains or basements.
This guide explains why it happens and how to fix it.
The Science Behind Late Summer Sewer Odours in Vancouver
Sewer smells are caused by gases inside your plumbing system. The main gas is hydrogen sulfide, which creates the rotten egg smell. This gas forms when waste breaks down inside pipes.
Warm weather speeds up this process. In late summer, pipes stay warmer for longer periods which increases bacterial activity. At the same time water inside P-traps can dry out. When that water evaporates the barrier is gone. Gas can then move into your home.
Health agencies note that sewer gases should not enter indoor spaces. Even small leaks can cause strong smells.
Why the Smell Gets Worse Right Now in the Lower Mainland
Late summer in the Lower Mainland creates the perfect conditions for odours. Even though Vancouver is known for rain, August and early September are often dry.
Here is what happens during this time:
- The ground dries out and that can shift soil around sewer lines.
- Roots search for water and sewer pipes become a target.
- Guest bathrooms or basement drains may not be used often.
- Dry air speeds up evaporation in P-traps.
These small changes add up. This is why many homes notice smells at the same time each year.
Common Causes of Sewer Smells in Greater Vancouver Homes
Several issues can lead to sewer odours.
Clogged or Slow Drains
- Grease, soap and debris build up over time. In summer this buildup grows faster.
- Kitchen sinks are a common problem. BBQ grease and cooking oils make it worse. This creates a layer inside pipes where bacteria grow.
Dry P-Traps
This is one of the most common causes. Drains that are not used often can dry out. This includes:
- Basement floor drains
- Laundry sinks
- Guest bathrooms
Once dry, nothing blocks sewer gas.
Tree Root Intrusion
Tree roots are a major issue in older neighbourhoods. Cities like North Vancouver and Richmond have many mature trees. Roots enter small cracks in pipes.
Over time they grow and block flow. This causes both odours and backups.
Sewer Line Damage or Poor Venting
Older homes may have clay or cast iron pipes. These materials can crack or shift over time. Blocked roof vents can also trap gas. Instead of venting outside, the gas moves back into the home.
Main Line Buildup
Years of waste buildup can create partial blockages. In summer, heat increases the smell from this buildup. Even a small restriction can create strong odours.
Local Vancouver Factors That Make It Worse
Some local conditions make this problem more common.
Clay Soil Movement
Vancouver has a lot of clay soil. It expands when wet and shrinks when dry. This movement puts stress on sewer pipes.
Mature Tree Canopy
Older neighbourhoods have large trees close to homes. Roots grow deep and wide and sewer lines are an easy source of water.
Indoor Air Drying
Air conditioners and dehumidifiers are more common now. They reduce indoor moisture. This speeds up P-trap evaporation.
Sewer System Changes
Metro upgrades and repairs can affect pressure in sewer lines. You can check updates from Metro Vancouver. Small pressure changes can push gas back toward homes.
How to Prevent Sewer Odours Before Fall Hits
Simple steps can prevent most odours.
Keep P-Traps Full
Run water in all drains every 1 to 2 weeks.
Focus on:
- Basement drains
- Guest bathrooms
- Laundry sinks
You can also add a small amount of mineral oil. This slows evaporation.
Avoid Grease in Drains
Never pour grease or oil down the sink. Let it cool and throw it in the garbage. This prevents buildup inside pipes.
Use Enzyme Cleaners
Enzyme cleaners break down organic material. They are safer than chemical cleaners and also work well for regular maintenance.
Schedule Professional Cleaning
Annual drain cleaning from Lew Plumbing helps remove buildup. Professional tools clean deeper than DIY methods. This is especially important for older homes.
When to Call a Professional Plumber in Vancouver
Some signs mean you should not wait. Call an emergency plumber if you notice:
- Strong smell that does not go away
- Smell that gets worse at night
- Slow drains with gurgling sounds
- Odours in multiple areas of the home
- Musty smell in basement or crawl space
These signs often mean a deeper issue. DIY fixes will not solve the root problem.
Breathe Easier with Lew Plumbing
Sewer smells are common in late summer. But they should not be ignored.
At Lew Plumbing, we provide:
- Professional drain cleaning
- Sewer line inspection with cameras
- Hydro jetting for deep cleaning
We serve homes across Vancouver, Burnaby, Coquitlam, and nearby areas. Our team understands local conditions like tree roots, clay soil, and older pipes.
We focus on fixing the source of the problem, not just the smell. If you notice sewer odours in your home, it is best to act early. A small issue can turn into a major repair if ignored.
Contact us today to schedule an inspection.
FAQs
Why does my drain smell worse in summer?
Warm temperatures increase bacteria growth. Dry air also causes P-traps to lose water. This allows sewer gas to enter your home.
Is a sewer smell dangerous?
Small amounts are usually not harmful, but should not be ignored. Long-term exposure is not recommended.
Can tree roots cause sewer smells?
Yes. Roots can block pipes and trap waste. This leads to strong odours and slow drainage.
How often should I clean my drains?
Most homes should have professional cleaning every 1 to 2 years. Older homes may need it more often.
Do you serve all Lower Mainland areas?
Yes. Lew Plumbing serves Vancouver, Burnaby, Coquitlam, Richmond, North Vancouver, and nearby cities. We are ready to help you keep your home clean, safe, and odour-free all year.
