Why Tree Roots Keep Ending Up in Los Gatos Sewer Lines

The trees are a big part of why people love Los Gatos. The oaks and sycamores along the older streets, the redwoods up in the hills, the whole canopy that makes a summer walk through town bearable. We love them too. We also spend a good part of every week cutting their roots out of sewer lines.

If your home was built before the 1970s, there is a good chance the pipe that carries wastewater from your house to the street is made of clay, laid in short sections with a joint every few feet. Those joints were sealed with mortar or rubber that has had fifty or more years to shrink, shift, and open up. A sewer pipe full of warm water and nutrients is the best meal a root will ever find, and it only needs a gap the width of a hair to get started.

How roots actually get in

Roots do not smash through pipes. They find moisture escaping at a joint or a small crack and send in fine feeder roots, thinner than a strand of spaghetti. Once inside, those feeders thicken and branch until they form a mat across the pipe. The mat catches paper and grease, and one day water stops moving. That is usually the morning someone calls us, often with a shower drain that will not empty and a toilet that gurgles when the washing machine runs.

The frustrating part for homeowners is that the tree responsible is often not even theirs. Street trees and a neighbor’s oak will happily follow the moisture across a property line. The roots do not care whose name is on the deed.

Why it keeps coming back

Running a cable machine through the line cuts the roots and gets things flowing again, usually within the hour. What it does not do is close the opening the roots came through. Cutting roots is like pruning a hedge. They grow back, and they grow back through the same joint. If your house needs the drain cleared every spring, that is not bad luck. That is a pipe telling you where its weak point is.

For lines with heavy buildup we sometimes follow the cable with hydro jetting, which scours the pipe walls clean instead of just punching a hole through the blockage. That buys more time between visits. It is still relief, not a cure.

The signs worth paying attention to

One slow drain is usually a fixture problem. Several slow drains at once point to the main line. Gurgling from a toilet or tub when another fixture drains means air is being pulled through a partial blockage. A patch of lawn that stays green and soft in August, when everything around it has gone brown, can mean the line is leaking into the soil there. Any of these is a good reason to look inside the pipe before it becomes a backup on a holiday weekend.

What a camera inspection settles

A sewer camera takes the guessing out of it. We run it down the line and watch the screen together. You see what we see: where the roots are, how many joints they have found, whether the pipe is intact between them or starting to crack and sag. Sometimes the answer is genuinely good news, one bad joint in an otherwise sound line. Sometimes the camera shows a pipe at the end of its life. Either way you are deciding based on what is actually down there, not on a guess.

Fixes that last longer than a season

When one joint is the problem, a spot repair on that section can be all the line needs. When roots have found their way in along the whole run, trenchless methods let us rebuild the line without digging a trench through your yard. A new liner cured inside the old pipe, or a new pipe pulled through in its place, gives you a smooth, jointless run that roots cannot get into. On the properties around downtown, where the lateral often runs under mature landscaping, a walkway, or a stone wall someone built eighty years ago, keeping the yard intact matters as much as the pipe itself. Our sewer services page covers the full range of repair options.

A note for the hillside neighborhoods

Homes up in the Los Gatos mountains, in the 95033 area, often have much longer sewer or septic runs than homes in town, and the lines cross slopes where the soil moves a little every wet season. Roots find those flexing joints quickly. If you are on the hill and your drains slow down every winter, the same camera inspection applies. Long lines fail quietly until they fail loudly.

We have been working on Los Gatos sewer lines since 1988, and the trees have been here a lot longer than that. If your drains are hinting at a problem, have someone look at the line before the roots finish the job.