How to Fix Sewer Backup: 5 Fast Solutions to Save Your Home From Damage

To fix a sewer backup, start by relieving pressure through your outdoor cleanout, then use a drain snake or call a pro for hydro jetting if the clog is deep. You may also need to install a backwater valve or replace damaged sewer lines for long-term protection.

Sewer backups aren’t just disgusting – they can destroy floors, cause mold, and lead to health hazards if not handled quickly. One of our top solutions, using the sewer cleanout, can stop a sewage flood in minutes and save you thousands in repairs. Whether you’re noticing the first signs or already facing a serious mess, this guide will show you exactly what to do, step by step.

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What Is Sewer Backup and Why It’s So Dangerous

Sewer backup happens when wastewater from your toilets, sinks, or tubs can’t drain properly and flows back into your home instead. This usually means there’s a clog, blockage, or damage somewhere in your sewer line. The pipe that takes wastewater away from your house and into the city sewer system or septic tank.

Here’s Why It’s a Big Deal

• Health Risks: Raw sewage carries bacteria and viruses that can cause serious illness.
• Property Damage: Floors, carpets, walls, and furniture can be ruined quickly.
• Mold Growth: Water damage can lead to mold in just 24–48 hours.
• Expensive Repairs: Cleanup and restoration can cost thousands if you wait too long.

Many homeowners only act when it’s too late — don’t be one of them. If you catch the problem early and know what to do, you can avoid most of the damage and stress.

Common Signs of a Sewer Backup

You don’t have to wait until sewage floods your bathroom to know something’s wrong. Look for these early warning signs:

• Gurgling sounds from toilets or drains
  
• Water backing up in the shower when you flush the toilet
  
• Slow drains in multiple sinks or tubs
  
• Foul sewage smells inside your house
  
• Overflowing floor drains in the basement or garage
  
• Water pooling near the sewer cleanout cap outside

These are all clues that something is blocking the main sewer line — not just a single sink or toilet. And once you see one, don’t ignore it. That backup can get worse very fast.

What Causes a Sewer Backup?

Understanding the causes will help you pick the right fix. Here are the most common reasons your sewer line may be backing up:

1. Tree Roots

Tree roots naturally grow toward moisture, and they love sewer pipes. If there’s even a small crack, roots will sneak in and grow, creating a huge blockage over time.

2. Grease Buildup

Pouring grease down the sink may seem harmless, but it cools and hardens inside pipes. Over time, it can block the entire line.

3. Flushed Non-Flushables

Things like wipes, feminine products, paper towels, and even “flushable” wipes don’t break down. They pile up and clog the line.

4. Collapsed or Damaged Pipes

Older homes may have clay or cast iron pipes that crack, collapse, or corrode with age.

5. Heavy Rain or Flooding

Too much water in the sewer system from storms can push wastewater back into homes, especially if your system lacks a backflow valve.

How to Fix Sewer Backup: 5 Fast and Effective Solutions

Now that you know what’s going on, let’s get into what you can actually do. Here are five proven solutions. Some you can do yourself, and some that may need professional help.

1. Use the Sewer Cleanout to Release Pressure

Most homes have a sewer cleanout, a white or black pipe sticking up from the ground with a cap — usually located near the house or in the yard.

What to Do:

• Locate the cleanout cap.
• Use a wrench or gloved hand to slowly remove the cap.
• If sewage is under pressure, it may be released here and drain into the yard instead of inside your home.

Why It Helps:

It relieves pressure in the system and may stop the sewage from backing up through your toilet or tub. It’s often the fastest way to prevent more damage.

2. Try a Sewer Auger (Drain Snake)

For moderate clogs, a powered drain snake — also called a sewer auger — can break through the blockage.

How to Use:

• Feed the snake into the cleanout or clogged drain.
• Turn it on and gently push forward as it rotates.
• Once resistance decreases, pull it back and run water to flush the line.

Good For:

• Tree roots
• Grease blockages
• Large clumps of toilet paper or wipes

Renting one from a hardware store is affordable, but if you’re not confident using it, you may cause pipe damage. When in doubt, call a professional.

3. Use a Sewer Jet or Hydro Jetting (Pro Solution)

Hydro jetting uses a high-pressure water hose to blast clogs out of your sewer line. It’s one of the most effective ways to clear out years of buildup.

Why It Works:

• Blasts away grease, roots, and sludge
• Cleans the entire inner wall of the pipe
• Restores full flow capacity

When to Use It:

• If you’ve tried snaking and the line still backs up
• If roots are the problem
• If the blockage keeps coming back

You’ll need to hire a licensed plumber for this one. But if your line is dirty or partially blocked, it’s often the best long-term solution.

4. Install a Backwater Valve

A backwater valve (also called a backflow preventer) is a one-way gate in your sewer line. It lets wastewater out but prevents city sewer water from backing into your home.

Benefits:

• Stops sewage from city lines during storms or floods
• Great for basements or homes in low-lying areas
• Required by code in many cities now

Installation:

This is not a DIY job. It requires a permit, digging into the main sewer line, and professional installation. But it can prevent backups for decades to come.

5. Replace or Reline the Damaged Sewer Pipe

If your sewer line is cracked, collapsed, or full of tree roots, no amount of snaking will help long term. You may need a permanent repair.

Options Include:

• Trenchless pipe lining (CIPP): Inserts a new pipe lining through the old one.
• Pipe bursting: Breaks the old pipe and pulls a new one into place.
• Traditional excavation: Dig and replace the old line completely.

These are major repairs, but if your line is broken, it’s the only way to stop the backups from happening over and over again.

What Not to Do When You Have a Sewer Backup

Some common mistakes can make things worse, not better. Avoid these:

• Don’t run water or flush toilets — It’ll just add to the backup.
• Don’t pour chemical drain cleaners — They rarely help and can damage pipes.
• Don’t wait to act — The longer you delay, the more damage you’ll face.
• Don’t ignore the cleanout — It’s your best tool for fast relief.

How to Prevent Future Sewer Backups

Fixing the problem is one thing — making sure it never happens again is even better. Here’s how to prevent sewer backups in the future:

✅ Regular Maintenance

• Have your sewer line cleaned or inspected every 1–2 years.
• Use a camera inspection to find hidden issues.

✅ Watch What You Flush

• Only flush toilet paper.
• Never flush wipes, even “flushable” ones.

✅ Avoid Grease in the Drain

• Pour grease into a can and throw it in the trash.

✅ Trim Tree Roots

• Avoid planting trees near sewer lines.
• Remove aggressive root systems early.

✅ Install Backwater Valves

• Especially if your area gets heavy rain or flooding.

Final Thoughts: Fast Action Can Save Your Home

Knowing how to fix a sewer backup can mean the difference between a small inconvenience and a costly disaster. The key is acting fast, using the right tools, and recognizing when you need help.

Whether it’s opening your cleanout, snaking the line, or calling in a pro for hydro jetting or repairs, these five solutions will help you stop the backup and prevent future damage.

Don’t wait for sewage to ruin your floors or your peace of mind. Take control of the situation now, and protect your home from serious harm.

What’s Next?

If you have sewer problems, don’t wait until they get worse. Call a plumber today and get your drain line checked out. New Flow Plumbing offers 24/7 emergency services and can help you with any plumbing problem. We use sewer camera technology to inspect your drain pipes—and clear them of obstructions—before they become too serious. Our licensed plumbers have years of experience fixing sewer systems and can help you restore service quickly. Make sure to contact us immediately.