Tree roots in a sewer line are one of the most common reasons an older Jacksonville home keeps backing up. The trees I see causing it most are oaks: live oaks, water oaks and laurel oaks, and many older neighborhoods have large, mature ones. Here’s how roots get in, how to tell when they have, and why cutting them out and fixing the way they got in are two different jobs.
How do tree roots get into sewer lines?
Roots need a way in. The tree usually isn’t the whole problem: roots get into a sewer through an opening that already exists, such as a deteriorated joint, a crack, a separated connection or other damage. A sewer line carries warm, nutrient-rich water, and moisture escaping through those gaps draws fine roots toward the pipe. Once a root tip gets inside, it has water and nutrients around the clock, so it grows into a dense mat that catches grease, paper and debris.
Older pipe materials are the most vulnerable. Clay sewer pipe was laid in short sections with many joints, and cast iron joints can loosen as the pipe ages. InterNACHI’s life-expectancy chart puts buried cast iron waste pipe at about 50 to 60 years, so original lines in older Jacksonville neighborhoods are often at an age where joints start to open. Sandy soil lets roots travel easily to reach them.
The tree usually isn’t the whole problem. Roots need a way in.
For more on how older drain lines age, see our cast iron pipe replacement page.
Which trees cause the most trouble?
In Jacksonville, I see oaks most: live oaks, water oaks and laurel oaks. Many older neighborhoods have large, mature oaks, and their roots spread wide. Any large tree or shrub near the sewer line can send roots toward it, though.
Where the tree sits matters too. A big oak between the house and the street, right over the path of the sewer line, is a much bigger risk than the same tree in a back corner of the lot.
What are the signs of tree roots in your sewer line?
Root problems tend to build slowly, then show up as a pattern. The earliest sign is often a toilet that gurgles or a tub that drains slower than it used to, especially when other fixtures are running. As the root mass grows, several drains slow down at once, because the blockage sits in the main line that every fixture shares. Backups that come back weeks or months after a drain was cleared are a classic root sign, since a cable can cut a path through the roots without removing them.
Outside, look for a soggy patch or an unusually green strip of grass along the path of the sewer line, which can mean wastewater is leaking from a damaged joint. A sewer smell in the yard or near a cleanout points the same way. If your home has a large oak within reach of the sewer line and more than one of these signs, a camera inspection is the next step.
| Sign | What it suggests | Next step |
|---|---|---|
| Toilet gurgles when a sink or shower drains | Partial blockage in the main line | Schedule an inspection |
| Several slow drains at the same time | Main line obstruction, not a single fixture | Limit water use and call a plumber |
| Backups that return after snaking | Roots left on the pipe walls and joints | Camera inspection before another cleaning |
| Wet or extra-green strip in the yard | Possible leak at a damaged joint | Camera inspection to locate it |
| Sewage in a tub, shower or floor drain | Main line blocked | Stop using water and call for emergency service |
How do plumbers remove tree roots from a sewer line?
A proper root job has three stages: see it, clear it, then decide whether the pipe needs repair. It starts with a camera inspection, which shows where the roots are entering, how dense the mass is and what shape the pipe is in. I find the actual entry point on camera, because that’s the difference between knowing what’s clogging the line and knowing why it keeps coming back. Older clay and cast iron lines can be cracked or thin, so they need to be checked before high-pressure cleaning.
Clearing is usually done with hydro-jetting, which cuts roots and scours grease and debris from the full pipe wall; our equipment runs up to 4,000 PSI. A mechanical cutter on a cable can open a line quickly, but it tends to leave root stubs behind. Cutting restores flow, but it doesn’t close the opening the roots came through. If that opening stays, the roots are likely to come back.
Cutting roots restores flow. It doesn’t fix the opening they came in through.
You can see how the first step works on our sewer camera inspection page, and how the clearing step works on our hydro-jetting page.
Repair options once the roots are out
| Option | How it deals with roots | Best fit when |
|---|---|---|
| Maintenance cleaning only | Manages regrowth but doesn’t seal entry points | The pipe is sound and a repair isn’t practical yet |
| Spot repair | Replaces the damaged section with new PVC | Roots enter at one or two joints |
| Trenchless lining (CIPP) | Creates a jointless pipe inside the old one | The line holds its shape but several joints are affected |
| Sewer line replacement | New pipe and new, sealed joints | The line is collapsed, badly offset or failing along its length |
Can you keep tree roots from growing back into your sewer line?
There’s no honest fixed timeframe for how fast roots come back. It depends on the condition of the sewer and how the roots are getting in. If roots are cut but the opening is left, they’re likely to return, so cleaning buys time rather than solving the problem. The most lasting prevention is repairing the entry point: replacing or lining the damaged section removes the joint or crack roots follow.
If repair isn’t in the plan yet, scheduled maintenance cleaning keeps regrowth from turning into a backup, and a camera check after the first cleaning gives you a baseline. When roots keep returning through the same damaged section, though, you’re treating the symptom each time. At some point it makes more sense to repair the section that’s letting them in. Before planting trees or large shrubs, find out where your sewer lateral runs and keep big trees well away from it.
Removing a large tree is a big decision with its own consequences, so talk to an arborist before cutting anything down. Removing a tree doesn’t remove the roots already in the pipe.
Homes on septic have a second target: roots also go after the drain field. Our septic system services page covers the drain field side.
Common tree root mistakes
- Treating a flowing drain as a fixed drain. Often just enough of a path has been opened through the roots while most of the restriction is still in the pipe.
- Cutting the roots and never finding the entry point. If the opening stays, the roots are likely to come back.
- Clearing the same damaged section over and over. At some point you’re paying to treat the symptom instead of repairing the section that lets roots in.
- Jetting fragile pipe without a camera look. If the pipe is broken, hitting it harder doesn’t repair it.
- Replacing the whole line before seeing inside it. If one section is damaged and the rest is good, there’s no reason to replace a good sewer.
How RiverCity handles tree roots in sewer lines
I start with a camera. Before jetting any older clay or cast iron line, I inspect it to find the roots, check the pipe’s condition and locate where the roots got in. If the line is sound, we clear it with hydro-jetting, then run the camera again so you can see the joints the roots came through.
Here’s a real example. We had a sewer stoppage at a house in Mandarin that looked like a straightforward drain cleaning. The camera found mature oak roots that had penetrated the sewer pipe. Cutting the roots wouldn’t have been a permanent repair, because of the defect that was letting them in.
So the job became a sewer line replacement. While the line was open, we also cut and removed the roots around the damaged line, so the new line wasn’t going back into the same problem. That job shows the difference between getting water moving and finding out why it stopped.
Then I explain the options in plain language: maintenance cleaning, a spot repair at the entry point, lining, or replacement of a failing line. I’ll tell you honestly whether cleaning is enough or whether we’d only be treating the symptom. You get a written, upfront quote before any work starts. Cost depends on the length and depth of the line, whether there’s an accessible cleanout or one needs to be installed, the pipe material, how many sections are damaged, and what sits above the pipe.
If sewage is already backing up, we offer 24/7 emergency service from our Southside and Northside locations. For damaged lines, learn how our sewer line repair process works.