Tree roots get into a sewer line through cracks and loose joints, pulled in by the water and nutrients inside the pipe. The fix starts with a sewer camera inspection, followed by root removal and, if the roots have broken the pipe, a repair.

Most homeowners discover they have tree roots in their sewer line the same way. One drain starts slowing down. Then another one does, and a toilet may gurgle when the washer empties. By the time these warning signs appear, the roots have been growing for a while. Clearing the roots gets the drains moving again, but they’ll keep coming back until the opening they entered is sealed. Finding that opening is the first step in understanding how tree roots get into sewer lines in the first place.

How Do Tree Roots Get Into a Sewer Line?

Roots don’t usually break into a healthy pipe. Instead, they find their way through small cracks, gaps, or loose pipe connections that develop over time.

A crack or loose joint in a sewer pipe lets out a little moisture and warm water vapor. The surrounding soil stays damp and full of nutrients, and tree roots grow toward it. Once a hair-thin root finds the gap, it can continue growing inside the pipe.

Inside the pipe, the root has water, food, and oxygen that help it grow into a larger root. It thickens over months into a root mass that can catch toilet paper, grease, and other debris, creating blockages that slow drainage. . As roots expand, they can also put pressure on the damaged section of pipe and make the problem worse.

Which Sewer Pipes Are Most at Risk?

Old pipes with joints, shallow lines, small-diameter pipe, and fast-growing trees are the biggest risk factors. The same review notes that roots are the cause of more than half of all sewer blockages.

Pipe type	Where you’ll find it	Root risk
Clay pipe	Older homes	High. Short sections mean lots of joints, and those joints loosen with age.
Concrete pipe	Some older homes and city lines	Moderate to high. Joints and cracks open as the pipe ages.
PVC pipe	Most newer homes	Lower. Glued joints resist roots, but a loose joint or a crack can still let them in.

Soil movement can also contribute to the problem in many areas. Clay-heavy ground swells when it’s wet and shrinks during a drought, and colder regions get the same push and pull through freeze and thaw cycles. That movement works on every pipe joint in the yard. A line that stayed tight for twenty years can open up after one hard, dry summer.

What Are the Warning Signs of Tree Roots in a Sewer Line?

Roots build slowly, so the early signs are easy to write off. Here’s what to watch for:

• Slow drains in more than one place: One slow sink is a local clog. Two bathrooms and the kitchen draining slowly at the same time points to the main sewer line.
• Gurgling: Listen to the toilet bowl when the tub drains. Bubbling means air is being pushed back through a partly blocked drain line.
• A sewage odor: You smell it inside the house or around the cleanout in the yard.
• The clog that keeps coming back: You snake the drain, it runs fine for a few weeks, then it slows down again. Roots regrow after a partial clearing. Repeat clogs on a schedule are one of the clearest signs of root invasion.
• A soggy or extra-green strip in the yard: Leaking sewage feeds the grass right along the line’s path.
• A sewage backup: Dirty water comes up in the lowest drain in the house. That’s a ground-floor shower or tub in most homes.

Is It Roots or Just a Clog?

Grease and wipes cause plenty of backups on their own, but so do roots. From inside your home, it can be difficult to tell the difference. A sewer camera inspection can identify the cause in a few minutes, and guessing usually costs more.

How Do Plumbers Find and Remove Tree Roots?

Start With a Sewer Camera Inspection

A plumber feeds a waterproof camera through a cleanout and down the sewer line. The camera shows where the roots got in and how much of the pipe they fill. It also shows any root damage, like a cracked, sagging, or collapsed section. The footage also pins down the location, so any repair targets one spot instead of the whole yard. Lasiter & Lasiter Plumbing uses video inspection for exactly this.

Clear the Roots

Two tools do most of the root removal work.

• Mechanical cutting: A drain cable fitted with cutting heads, often called root saws, chews through the root mass and opens the line back up.
• Hydro jetting: High-pressure jetting runs water at about 4,000 psi to scour the pipe walls. It flushes out the root fibers and greases a cable leaves behind. That pressure can harm a weak pipe, so the line gets inspected first.

Thick roots often need both. Cut first, then jet.

Does Copper Sulfate Root Killer Work?

Many store-bought root killers use copper sulfate. A chemical root treatment can slow regrowth after a line has been cleared. It won’t open a pipe that’s already packed with roots. It won’t fix a crack, either. Read the label before pouring anything into a drain. For a long-term solution and to prevent costly pipe damage, don’t hesitate to call your local plumber.

When Does the Pipe Need Repair?

Clearing roots treats the blockage. The opening they came through is still there, and the roots will be back. In smaller pipes, root removal every year or two is common.

If the camera shows a broken pipe joint, a crushed section, or an old pipe that has sagged, repairing that section is the lasting fix. Trenchless pipe repair, which can replace or line a pipe with less digging and damage to your yard, works for some pipe line. A camera inspection can tell you if this is an option for you. 

Common Questions Homeowners Ask

Who pays to fix roots in a sewer line?

In many cities, the homeowner owns the private sewer line that runs out to the main city sewer. Roots on private property are the homeowner’s responsibility to repair. The city takes care of the main. When several houses on one street back up at once, the trouble may be in the city’s sewer system. 

Will my insurance company cover it?

Don’t count on it for the pipe. Most homeowners policies leave out sewer backup unless that coverage is added. Roots are also viewed as a maintenance issue. Call your agent and ask about sewer backup and service line coverage now, before you need it.

Should I cut down the tree?

Not as a first step. Seal the opening, and the roots lose their way in. When you plant new trees, keep species with aggressive root systems, like willows and silver maples, well away from the line.

How do I keep roots out?

• Plant with the line in mind: Find out where your sewer line pipe runs before you plant anything big.
• Watch what goes down: Keep grease and wipes out of every drain pipe in the house. Roots catch whatever flows past them.
• Stay on a schedule: If roots have been cleared from your line before, plan on routine sewer cleaning. A professional plumber can tell you how often your line needs it.

Lasiter and Lasiter: Your Partner in Sewer Line Root Problems

Lasiter and Lasiter Plumbing has served the Fort Worth area since 1974. When roots show up, we start with a video inspection so you can see the problem yourself. Then we clear the line and handle the sewer repair if the pipe is damaged. We give estimates in person, after we’ve seen the job, because an accurate number is worth more than a fast one.

Seeing slow drains or smelling sewage? Call Lasiter & Lasiter Plumbing or request a free estimate.