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Sewer Backups, Prevention & Sewer Repair in Toronto

Basement drain backing up, slow drains, or recurring sewer issues?
We diagnose sewer problems properly — and fix them the right way.

Sewer issues worsen quickly and can cause major property damage
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What Causes Sewer Backups In Toronto Homes

Why sewer backups are common in older Toronto properties

Many Toronto homes were built with clay sewer pipes, outdated drainage layouts, and systems that were never designed for today’s usage demands.

Common causes include:
• Tree root intrusion
• Aging clay sewer pipes
• Pipe bellies (negative slope)
• Collapsed or cracked pipe sections
• Trap and breather
• Improperly installed cleanouts

Clay Sewer Pipes

Why clay pipes fail over time

Older sewer systems commonly used clay pipe, which was installed in short sections and sealed with mortar at each joint.

Over time:
• Soil shifts
• Mortar joints deteriorate
• Small gaps form

These gaps allow moisture to escape — and tree roots are naturally drawn to moisture.

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Tree Root Intrusion (How It Really Happens)

Why roots are so destructive underground

Tree roots are extremely powerful and intelligent in how they grow.

Important facts:
• Tree roots can extend two to three times wider than the tree’s visible canopy, often reaching 50–100 feet from the trunk.
• Roots grow deep in search of moisture and nutrients
• Cutting down a tree does NOT remove the roots — roots often continue growing for years.
• Roots naturally find weak points such as:
• Mortar joints
• Cracks
• Low sections holding water (pipe bellies)

Many times we have discovered sewer pipe installations reinforced by wrapping the joint in chicken wire and pouring concrete around.
Unfortunately, this only protected the top and sides — not the underside, where roots eventually find their way in.

Pipe Depth & Why Repairs Are Complex

How deep sewer lines are typically buried

In Toronto, the main sewer line leaving a property is commonly 6 to 8 feet deep, sloped toward the city sewer connection

This depth makes diagnosis and repair decisions critical — guessing is not an option. We have the tools and experience to accurately locate.

Bellied Pipes (Negative Slope)

What is a sewer belly and why it matters

A belly occurs when a section of the sewer pipe sinks, creating a low point where water and waste sit instead of flowing.

Why this is a problem:
• Standing water accelerates deterioration
• Waste buildup increases
• Roots are attracted to nutrient-rich, wet areas
• Blockages return repeatedly due to the flow significantly slowing down and or stopping when hitting the sitting waste

Trees naturally sense moisture and nutrients and will target these low sections aggressively.

When To Repair A Section Vs Replace The Entire Line

Spot repair vs full sewer replacement

Partial repair may be appropriate when:
• Damage is isolated
• Pipe slope is otherwise correct
• Remaining pipe is structurally sound

Full replacement is usually best when:
• Multiple joints have failed
• The pipe has repeated root intrusion
• There are multiple bellies
• The line is undersized or severely deteriorated

We always explain findings clearly before recommending any replacement.

Trap & Breather Systems (Common In Toronto)

What they are and why they cause problems today

Many older Toronto homes still have a main sewer trap and breather.

Originally, this was installed:
• Before individual fixtures had traps
• To block sewer gases, rodents, and debris from entering homes
• As part of an open-loop drainage system

Today, plumbing systems are closed-loop, meaning:
• Every fixture has its own trap
• Sewer gases are already contained

Because of this:
• Trap and breather systems are no longer permitted
• They create severe service issues
• They trap debris and sediment
• Large drain snakes and cameras often cannot pass through
• Sediment buildup at the bottom of the trap makes clearing extremely difficult

Modern Solution: Cleanouts & Backwater Valves

Why trap & breathers should be removed

Best modern replacements include:
• Back-to-back cleanouts (allowing access in both directions)
• Backwater valves (Rebates Available! Up to $3400, 100% success rate), which prevent city sewer backups from entering the home

Backwater valves are especially effective because:
• They block reverse flow from the city drains overflowing during heavy rain events
• They are code-approved
• The City of Toronto offers rebate programs for flood prevention upgrades

Prevention & Maintenance (Avoid Future Backups)

How to reduce sewer backup risk:
• Periodic sewer inspections
• Drain jetting for buildup and roots
• Removing obsolete trap and breather systems
• Correcting slope or bellies when identified
• Installing backwater valves where appropriate

Why Choose Canadian Plumbing

Experienced with Toronto sewer systems
• Extensive experience with older Toronto infrastructure
• Licensed & insured plumbers
• Camera inspections and proper diagnostics
• Honest recommendations — repair only when justified
• Clear pricing before work begins

Serving Toronto

We provide sewer backup, prevention and repair services within the City of Toronto.

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Concerned About a Sewer Backup or Aging Sewer Line?

Call now to have your sewer system inspected and properly assessed before the problem escalates.

CALL NOW – 647-502-7545

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