Hydro Jetting
Blast grease, scale and roots out of a pipe with pressurized water when a cable left it partly blocked.
Homeowner guide
Tree Roots in a Sewer Line in Louisville, CO: What to Do
Roots seek water, and a sewer pipe is a steady source. Even a hairline gap at a joint is enough. The result is a line that clogs again and again, until the roots and the opening are dealt with.
By the Flatirons Express Plumbing team ·
Signs you have roots
Slow drains in several fixtures, gurgling when you flush, and a main line that backs up after being cleared a few months ago are classic signs. Outside, a lush green strip of lawn along the pipe path can mean leaking water feeding the grass.
The older the house and the bigger the trees, the more likely it is. Roots come from trees on your lot or a neighbor's.
How roots get in
Clay pipe has joints every few feet, and old joints loosen. Cast iron can corrode. Even PVC can have a poor joint or a crack from settling. Warm waste and moisture drift out through the opening, and fine roots follow it in.
Once inside, roots branch into a mass that catches paper and waste. They thicken over time and can lift or split the pipe. A clearing may last months, then the line clogs again.
Ground movement makes it worse
The Colorado Geological Survey calls expansive soil the state's most significant geologic hazard, with disruption of pipelines and sewer lines among its effects. Clay swells and shrinks, shifting a lateral enough to open a joint.
That gives roots an entry point that did not exist when the pipe was laid. It also explains why a line can go years without trouble, then start clogging.
Warning signs and what they mean
Root intrusion rarely shows up all at once. These signs build over time.
| Sign | What it suggests | Next step |
|---|---|---|
| Slow drains in several fixtures | A partial blockage in the main line | Try a snake, then watch for a return |
| Gurgling when water runs | Air trapped by a restriction | Schedule a camera inspection |
| Repeated backups after clearing | Roots regrowing or a damaged pipe | Look at repair options |
| Soggy or sunken spot in the yard | A broken line leaking | Call promptly for a camera check |
Clearing and repairing
A cutting head on a cable can chop roots, and hydro jetting can scour them from the walls. Both clean the pipe but do not close the gap. Roots return unless the joint is repaired.
A camera inspection shows where the roots enter and what shape the pipe is in. A spot repair, a liner or a replacement stops them. See sewer line repair for the options.
Chemicals and home remedies
Copper sulfate and foaming root killers are sold for sewer lines. They can slow roots but also harm the environment and may be restricted. They do not repair the pipe. Treat them as a stopgap, not a cure.
Never pour chemicals into a line you plan to have cleared. They are a hazard to the plumber and may damage old pipe.
Which trees cause trouble
Roots go where water and nutrients are. Fast-growing trees with wide, shallow root systems, such as cottonwoods and willows, are well known for seeking out sewer lines, and older silver maples and similar species have the same reputation. Even so, any large tree close to a lateral can cause problems.
Planting distance matters. Before adding a tree near a sewer line, find where the lateral runs and choose a species with a less aggressive root system. Your utility or a locating service can mark the line before you dig.
What a camera will show
A camera on a flexible cable travels through the line and sends back video. Roots show up as fine hair-like threads at a joint or as a thick mat that fills the pipe. The camera also shows cracks, offsets where pipe sections have separated and bellies where the pipe has sagged.
The footage helps decide the fix. A short run of root intrusion may respond to cutting and hydro jetting. A broken or collapsed section needs repair, and a line in poor shape throughout may call for replacement.
Talking to your insurer and neighbors
Some homeowner policies cover sewer line damage only with a specific endorsement, and many exclude damage from roots and age. Read your policy before work, and ask what documentation the insurer wants if you plan to file a claim.
If the tree that is causing trouble sits on a neighbor's lot, or the line is shared, responsibility can be complicated. Take clear video and photos, and speak with your utility or a local professional about who handles what.
Planning ahead for an older lateral
If your house is decades old, ask when the sewer line was last inspected. A camera look before problems appear gives you a baseline and lets you plan repairs on your schedule instead of in the middle of a backup.
Keep a record of every cleaning and repair. If a line needs frequent clearing, a repair may cost less over the years than repeated emergency calls. See sewer line replacement for what that involves.
Prevention
Know where your lateral runs and plant trees well away from it. Choose species with less aggressive roots near the line. Schedule a camera inspection every few years if you have large trees.
If you are buying a house with mature trees, check the lateral before closing. It is a smaller expense than a surprise replacement.
Quick answers
Tree root questions
They can crack or lift a pipe over time. A repair stops the damage.
It depends on the pipe and trees. Some lines need clearing yearly. A repair is the lasting fix.
Removing a tree stops new growth, but roots in the pipe remain. The pipe still needs clearing and repair.
Often not. Some policies offer sewer line coverage as an add-on. Check yours.
Services that connect to this topic
Sewer Camera Inspection
Run a camera through the sewer to see its condition before a home purchase or a repair decision.
Sewer Line Repair
Mend a sewer pipe that is cracked, shifted or full of roots, whether the fix is one spot or a long run.
Keep reading
Why your house smells like sewer
A sewer smell has a short list of causes. Most start with a dry trap or a cracked pipe, and each has a different fix.
A toilet that refuses to flush
Most flush failures are a tank problem or a clog. Check the water level, the flapper and the chain before you call.
Tiny flies at the drain and how to end them
Small flies that keep landing near a sink, tub or basement floor drain are breeding in the pipe. Confirm it, clean it and watch for bigger trouble.
Roots clogging your line again?
Call and describe the history. A dispatcher can connect you with a local contractor.