Tree Roots in Your Sewer Line? Here’s What to Do

Out of all the plumbing misadventures you could have, tree roots in your sewer line are among the sneakiest. Roots love moisture and, unfortunately, your sewer line is an easy target. Sewer lines carry water and nutrients, which is exactly what thirsty roots search for underground. Over time, even a small crack or a loose joint can invite tree roots, causing slow drains and clogs. Once a hair-thin root slips inside, it keeps growing, catching toilet paper and debris until the line is partially or fully blocked.

This problem is common in older homes. Sewer lines made of clay, cast iron, or other older materials tend to have more joints and are more prone to cracking or shifting, which gives roots more places to get in. Newer PVC lines can be affected too, particularly at connection points.

The good news? If you catch the issue early, you can fix it without digging up your yard. Here's how to get rid of tree roots in your sewer line, how to spot the problem before it becomes an emergency, and how to keep roots from coming back.

Common Warning Signs of Tree Root Growth

While tree root invasion happens underground, you can catch it early if you know what to look for. Most signs show up first in your drains and then gradually appear in your yard. If you notice more than one of the signs below, a root blockage is more likely.

• Slow & Gurgling Drains: If water drains slowly or your toilet gurgles when you flush, it could mean that a tree root is blocking the sewage line. When air gets trapped behind a partial blockage, it escapes through your fixtures as gurgling sounds. Slow drains in several fixtures at once point to a main line problem rather than a single clogged sink.
• Backups: If you're experiencing clogs or frequent backups, even after snaking and plunging, tree root growth may be the culprit. A clog that keeps returning within days or weeks usually means something is physically inside the pipe, such as roots, that a plunger can't clear.
• Foul Odors: Catching a whiff of sewage in your backyard or basement? It could mean the sewer line is cracked or blocked by roots, allowing gases to escape. Sewer gas smells like rotten eggs and should never be ignored, because a break in the line can also release wastewater into the soil around it.
• Unusually green patches of grass: Notice an oddly green or wet patch of grass? A leaky sewer line caused by root intrusion may be to blame. Wastewater acts like fertilizer, so a lush, soggy, or sunken spot over the line's path can mean there is a leak.
• Bubbling drains: Does your tub or shower drain gurgle when you flush the toilet? This could be caused by tree roots blocking the main line. Because all your drains connect to the same main sewer line, a blockage there can push air and water back up through the lowest fixtures in the house first.

If you aren't sure what's causing the problem, a camera inspection is the most reliable way to find out. A small waterproof camera is fed into the line, so a plumber can see the roots, the cracks, and the condition of the pipe directly instead of guessing.

How to Get Rid of Tree Roots in the Sewer Line

When you notice slow drains or frequent backups, it's tempting to reach for drain cleaners and hope for the best. Unfortunately, most of these over-the-counter solutions don't touch tree roots. Worse, they can corrode your pipes, and they only treat the clog near the surface while the roots keep growing farther down the line.

Instead, here's how to get rid of tree roots in your sewer line safely and effectively:

Chemical root treatments (the right kind)

Professional-grade root killers are specifically designed to kill tree roots in sewer lines without damaging your pipes. These products are often flushed into the line, where they coat the pipe walls and the roots inside, breaking down existing growth and preventing regrowth. They work on the roots inside your pipe. They do not harm the tree itself, because the part of the root system that grows in your yard is not affected.

Can you use them yourself? Technically, yes. Many of these products are available at hardware stores. But before you begin pouring products down your drain, you need to know what you're dealing with. Using a product on a line that is already cracked, collapsed, or heavily blocked can waste time and money, and the treatment won't reach roots it can't get to. Check your local regulations and the product label as well, since some ingredients are restricted in certain areas.

We recommend having your line scoped with a camera first. If root growth is minor, a chemical treatment may be all you need to eliminate tree roots in the sewer line. If the camera shows heavy roots or damaged pipe, you'll know to move on to a stronger solution before the problem gets worse.

Professional Augering

When chemical root treatments aren't enough to get rid of tree roots in the sewer line, professional augering is often the next step. Augering is also called sewer snaking or power rodding, and it is the standard method for clearing a line that is already blocked.

This process uses a specialized machine with a rotating blade attachment to cut through thick roots. The cutting head travels through the line and shreds the roots along the way, which clears a path for water to flow again. Professional equipment is far more powerful than a store-bought hand snake, which often can't cut through dense roots and can get stuck or damage the pipe.

It's a fast, effective way to clear the line and restore flow. Unlike chemical treatments, which take time to work and may only partially kill the roots, augering physically removes them on the spot. For lines with heavy buildup, hydro jetting is another option, since it uses high-pressure water to scour the inside of the pipe after the roots are cut.

Augering clears the roots but does not repair the opening they came through. If the pipe has a crack or a bad joint, roots can return, which is why follow-up inspection and maintenance matter.

Regular Maintenance

Prevention is always the best way to avoid tree root sewer line repair costs. Roots will keep seeking water as long as there is a way in, so the goal is to catch growth early and make your property less inviting to them. Here's what we recommend:

• Annual Inspections: Even after removal, tree roots often grow back, especially if the entry point in the pipe hasn't been repaired. We recommend scheduling annual camera inspections to catch root growth before it causes a backup. Homes with mature trees, older sewer lines, or a history of root problems may benefit from checking more often. An inspection also shows whether the pipe is cracked or shifting, so you can plan any repair on your schedule and not during an emergency.
• Root Barriers: There are two types of root barriers, and both are designed to redirect roots away from the sewer line:
  • Physical: These are usually made from plastic or metal and are installed vertically in the soil. They form a wall that physically blocks roots from growing toward your sewer line. They work best when installed at the right depth and distance from the pipe, so placement is worth discussing with a professional.
  • Chemical: These come in the form of treated gels or fabrics containing root-inhibiting compounds like copper sulfate. When installed near a sewer line, they create a treated zone in the soil that discourages root growth without harming the tree.
• Tree Removal: While tree removal is a permanent solution, we treat it as a last resort. Why? Removing a tree can be expensive, may require permits, and often means losing valuable shade. Some trees are also protected or regulated by your city, so check local rules before removing one. That said, if the tree is too close to your sewer line and is causing repeated damage, removal might be the smartest long-term solution to tree root sewer line repair costs. If you're planting new trees, choose a spot well away from your sewer line, and ask about species with less aggressive root systems.

Get to the Root Cause of Your Sewer Issues

Whether it's a slow drain, strange odor, or a yard that's suddenly too soggy, we can quickly diagnose the issue and recommend the right fix before it turns into a costly repair. Our technicians use camera inspections to see exactly what's happening inside your line, so you only pay for the work your sewer line actually needs. Stephens Plumbing has served homeowners and businesses across the South Bay and Orange County, and our team is available 24/7 for plumbing emergencies. Contact us today to schedule service!