Tree roots in the sewer line: why a camera is the only way to know

The sewer lateral runs from the house to the city main, and it is the homeowner's responsibility for most or all of that distance. It is buried, so nobody looks at it until it backs up, and by then the repair is urgent and the price is whatever it is.

Why roots get in

Roots do not break into sound pipe. They find an opening that already exists, at a joint that has shifted, a crack, or a bad connection, and they grow toward the water and nutrients. Once inside, they fan out into a mat that catches paper and grease.

The trees that cause us the most trouble in San Diego are ficus, which is planted as a street tree across older neighborhoods and has famously aggressive roots, along with eucalyptus, pepper and liquidambar. A ficus thirty feet from the house can reach the lateral easily.

Pipe material tells you the risk

Clay pipe, common in houses built before about 1970, comes in short sections with mortared joints, so it has a joint every few feet for roots to find. It is also brittle.

Cast iron corrodes from the inside and scales up, and in older North Park and Kensington houses we find sections that have rotted through at the bottom.

Orangeburg, a tar impregnated fiber pipe used in some post-war construction, deforms into an oval and collapses. Finding it is effectively a finding that the line needs replacing.

ABS and PVC from the 1970s onward are glued and continuous, and they do much better, though a bad slope or a settled section still causes standing water.

What the camera shows

We push a camera the length of the lateral and record it. That gives you the material, the condition, any root intrusion and how far in, offsets where sections have shifted, bellies where waste stands instead of flowing, and the connection at the main. The counter on the camera tells you how many feet out a problem sits, which is what a plumber needs to quote.

A scope is not part of a standard home inspection. It is an add-on, and on any house over about forty years old with mature trees it is the best value in the whole transaction. The difference between snaking a line and replacing one runs from a few hundred dollars to well over ten thousand, and a twenty minute camera run is what tells you which conversation you are in.

If roots are found

Cutting them clears the blockage and buys time, usually a year or two, since the opening is still there. Lasting fixes are a spot repair at the damaged section, a cured in place liner, or a pipe burst replacement. Which one applies depends on how much of the run is bad, and that is what the video is for.