When Tree Roots Invade Your Sewer Line: Signs, Prevention, and Solutions

Tree roots and sewer lines don’t mix well—yet tree roots naturally seek out moisture, making your underground pipes an ideal target. Over time, even a small crack in your sewer line can attract roots, leading to blockages, backups, and costly repairs.
Ignoring root intrusion can cause extensive plumbing damage, affecting your entire property. But how can you tell if tree roots are invading your pipes? What can you do to prevent this issue? And if roots have already taken over, what are the best solutions?

How Tree Roots Invade Sewer Lines
Tree roots naturally seek out moisture. If there’s a crack or small leak in your underground sewer pipes, the roots will grow toward the source, eventually breaking into the pipe and expanding inside.
Once inside the sewer line, roots:
🔹 Absorb water and nutrients, growing thicker and stronger over time.
🔹 Form dense root masses, trapping waste and causing severe blockages.
🔹 Expand the cracks, leading to pipe fractures and structural failure.
Certain trees—such as willows, maples, and oaks—have aggressive root systems that are more likely to invade pipes. However, any tree near your sewer line can pose a risk.

Signs That Tree Roots Are Clogging Your Sewer Line
Tree root intrusion is a gradual problem. It often starts with small, subtle plumbing issues before turning into a major emergency. Look out for these warning signs:
1. Slow Drains Throughout the House
If multiple drains (toilets, sinks, bathtubs) are draining slowly, it could indicate a partial blockage in the sewer line caused by roots.
2. Frequent Toilet Backups
Tree roots act like a net, catching debris like toilet paper and waste. If your toilet backs up regularly despite plunging, roots might be the culprit.
3. Gurgling Sounds from Drains
Unusual gurgling or bubbling noises from toilets or drains often signal air trapped by a blockage, which can be caused by root growth.
4. Unpleasant Sewer Odors
If you notice a rotten egg or sewage smell coming from drains or your yard, it could mean roots have cracked your sewer pipe, allowing odors to escape.
5. Patches of Lush, Green Grass
Tree roots feed on wastewater nutrients, creating unusually green, thriving patches of grass over your sewer line—especially during dry seasons.
6. Sinkholes or Soft Spots in Your Yard
A leaking or broken sewer line due to root damage can create soft, soggy ground or even sinkholes in your yard.
7. Sudden Increase in Water Bills
A damaged sewer pipe may cause water loss, leading to an unexplained spike in your water bill.

How to Prevent Tree Roots from Invading Your Sewer Line
Preventing root intrusion before it starts can save you from expensive repairs. Here’s how to protect your sewer system:
1. Be Mindful of Tree Placement
Before planting trees, check where your sewer lines are located. Avoid planting deep-rooted trees near sewer pipes.
Better tree options: Smaller trees like dogwoods, cherry trees, or Japanese maples have less invasive roots.
2. Install a Root Barrier
Root barriers are physical barriers placed around pipes to redirect root growth. These barriers:
✔ Are made of metal, plastic, or chemical treatments.
✔ Can be installed during new landscaping or plumbing work.
3. Schedule Regular Sewer Inspections
A video camera inspection can detect small root intrusions before they become major blockages. Annual sewer inspections are recommended, especially if you have older pipes.
4. Use Root-Killing Treatments
Preventive treatments, such as foaming root killers, help stop small root growth before it becomes a serious problem. Look for root-killing products that contain copper sulfate or dichlobenil.
5. Upgrade to PVC or HDPE Pipes
If your home has older clay or cast-iron pipes, consider upgrading to PVC (polyvinyl chloride) or HDPE (high-density polyethylene) pipes, which are more resistant to root intrusion.

How to Remove Tree Roots from Sewer Pipes
If tree roots have already invaded your sewer line, here are the most effective removal methods:
1. Hydro Jetting (Best for Clearing Root Blockages)
🔹 Uses high-pressure water jets to blast away roots and debris.
🔹 Is a non-invasive, eco-friendly solution.
🔹 Ideal for removing roots without damaging pipes.
2. Mechanical Root Cutting
🔹 A professional plumber inserts a powered cutting tool into the sewer line to cut and remove roots.
🔹 Effective for temporary relief, but roots can grow back over time.
3. Chemical Root Killers
🔹 Foaming root killers coat the inside of pipes, killing roots on contact.
🔹 Useful as preventative maintenance after hydro jetting.
4. Pipe Relining (Permanent Solution)
🔹 Cured-in-place pipe (CIPP) lining creates a new, seamless pipe inside the damaged one, sealing out roots permanently.
🔹 A great alternative to full pipe replacement.
5. Sewer Line Replacement
🔹 If the damage is severe, pipe replacement may be necessary.
🔹 Modern techniques like trenchless pipe replacement can minimize yard disruption.

When to Call a Professional Plumber
​If you suspect tree roots are damaging your sewer line, don’t wait until it becomes a major plumbing emergency. Call a licensed plumber if:
✔ Your drains keep backing up despite DIY efforts.
✔ You notice sewage smells, wet spots, or lush grass near your sewer line.
✔ You want to schedule a camera sewer inspection.
✔ You need hydro jetting, root removal, or pipe repairs.