Main drain backups are one of the most urgent plumbing emergencies for Oakville homeowners. When dirty water rises through your kitchen sink, bathroom sink, bathtub, or floor drain, it means the main sewer line — the pipe that carries wastewater out of your entire home — is blocked.

A main drain clog can escalate within minutes, causing:

• Sewage to rise into sinks and tubs
• Water contamination
• Flooding inside kitchen cabinets and flooring
• Damage to lower-level units in condos
• Expensive clean-up costs if ignored

Today, our team at 17 Plumbing & Construction Design Ltd. responded to yet another severe main drain backup in an Oakville condo, where wastewater was pushing up through the kitchen sink and bubbling inside the bathtub. With cold weather, holiday cooking, and increased grease in pipes, we are seeing this every day.

This guide will help you understand:

• Why main drains clog
• What signs to look for
• What to do immediately
• How plumbers professionally clear the blockage
• How to prevent future backups

What Is a Main Drain Backup?

Your home has one main drain line (also called the main sewer line). Every fixture connects to it:

• Kitchen sinks
• Bathroom sinks
• Toilets
• Bathtubs and showers
• Laundry drains

When this pipe becomes clogged, wastewater has nowhere to go — so it flows backwards, returning through the path of least resistance.

In houses, this is often the kitchen sink or basement drain.
In condos, it can come up through the bathtub or unit stack.

A main drain backup is not a small clog. It requires immediate attention.

Common Causes of Main Drain Backups in Oakville

Oakville homes — especially those built before 1990 — experience these issues frequently due to older sewer infrastructure, tree roots, and seasonal conditions.

Here are the top causes:

1. Grease & Food Buildup

Holiday cooking season produces heavy grease. When poured down the sink, it cools inside the pipe and becomes rock-hard.

2. Tree Roots

Large trees in neighbourhoods like Glen Abbey, River Oaks, Kerr Village, and Bronte frequently invade clay sewer pipes.

3. Wipes, Paper Towels & Hygiene Products

These do NOT dissolve and can block the entire main line.

4. Condo Kitchen Stack Blockages

Condos with older cast-iron stacks frequently clog due to grease, scale, and years of buildup.

5. Broken or Collapsed Sewer Pipes

Older Oakville homes often have aging clay or cast-iron pipes that crack or collapse.

Signs You Have a Main Drain Backup

If you see ANY of these signs, treat it as an emergency:

✔ Dirty water rising into the kitchen sink

Major sign the blockage is deep in the main line.

✔ Bathtub filling with sewage

When using the sink or flushing the toilet.

✔ Gurgling or bubbling noises

Especially when flushing or draining water.

✔ Multiple drains slow at the same time

Kitchen + bathroom + tub = main line issue.

✔ Sewage smell near drains

Indicates waste is trapped below.

✔ Toilet water rises when you run the sink

This is classic “main drain blocked” behaviour.

What to Do Immediately (Before Damage Spreads)

1. STOP using water

Turn off faucets, stop laundry, and do not flush toilets.

2. Identify the first point of backup

Kitchen sink and bathtub backups are early warning signs.

3. Do NOT use chemical drain cleaners

They don't reach deep blockages and can damage pipes.

4. Call an emergency plumber right away

Main line issues escalate quickly and can cause flooding.

📞 Emergency Oakville Hotline: 647-862-1317

At 17 Plumbing, we provide 30-minute emergency arrival when available.

How Plumbers Fix Main Drain Backups (Professional Process)

Here’s what our licensed plumbers do onsite:

1. Inspect All Fixtures

We confirm which parts of the house are backing up to locate the blockage.

2. Locate the Access Point

In condos: hallway or unit kitchen stack access
In homes: basement cleanout or main floor cleanout

3. Set Up Floor Protection

Plastic sheets, towels, mats — we ensure no contamination spreads.

4. Use Commercial Drain Snaking Equipment

Our professional machines cut through:

• Grease
• Tree roots
• Wipes
• Hardened scale
• Food buildup

5. Flush and Test the Line

We run multiple sink and toilet tests to verify full flow.

6. Optional: Drain Camera Inspection

To visually identify cracks, roots, or breakage.

7. Full Report for Homeowners or Condo Management

We provide photos, videos, and written findings for transparency.

Why 17 Plumbing Is Oakville’s Most Trusted Emergency Drain Plumber

We aren’t just another plumbing company.
We are Oakville’s 5-star rated, award-winning, fully licensed team:

• ✔ Part of the Oakville Chamber of Commerce
• ✔ Featured in Oakville News Spotlight
• ✔ Nominated for Top Choice Award 2026
• ✔ WSIB compliant, fully insured
• ✔ Specialize in condo stack cleaning
• ✔ Fast emergency response for houses & condos
• ✔ Professional reporting for property managers
• 
  

We service Oakville, Burlington, Milton, Halton Hills, and Mississauga.

How to Prevent Future Drain Backups

✔ Avoid pouring grease down the sink

Use a jar to collect grease instead.

✔ Don’t flush wipes

Even “flushable” wipes cause blockages.

✔ Schedule annual drain cleaning

Especially for condos with aging stacks.

✔ Install a backwater valve

Prevents wastewater from flowing back into your home.

✔ Use drain strainers

Catch food particles and hair.

If You Have a Main Drain Backup — Act Fast

A main drain clog is a serious plumbing emergency. Ignoring it can lead to:

• Sewage contamination
• Thousands in damage
• Insurance claims
• Flooding into lower units

If your sink, tub, or toilet is backing up right now, call us immediately.

📞 647-862-1317
17 Plumbing & Construction Design Ltd.
Oakville’s #1 Emergency Drain Cleaning Experts