Are roots in old clay sewer pipes a big deal when buying?

Vitrified clay pipe is hard, but it is laid in short sections with a joint between each one. The City of San Luis Obispo notes that clay joints are subject to root intrusion and that the pipe is brittle and prone to cracking. It puts a typical clay lifespan at 50 to 60 years, and says clay was common before 1940. Roots follow the moisture that seeps from those joints, slip in, and grow into a mass that catches everything else that comes down the line.

The City of Phoenix says roots from trees and invasive shrubs, such as oleanders, are the second biggest problem in its sewer lines after grease. Roots find their way through pipe joints or other openings and form a root ball once inside. In the EPA's national study of blockage events, roots accounted for 22 percent, and another 4 percent involved roots and grease together. So roots are common enough that you should expect to see them on some scopes.

### Roots alone are usually fixable

Many root-filled clay lines can be repaired without a trench. NASSCO says cured-in-place lining works when the old pipe has cracks, fractures or holes but has generally kept its shape, and calls it a permanent solution against root intrusion in laterals, the most common problem it sees there. That is why a clay pipe with roots but no collapse is often a repair rather than a disaster. Our page on whether to fully reline, partly reline or do nothing walks through the choice.

### Roots plus damage are a different conversation

If the roots came in through a crack, an offset joint or a broken section, cleaning only buys time. InterNACHI, the home inspectors' association, says a sewer scope can reveal blockages, damage to the pipe, evidence of backflow into the home, and pipe deterioration or separation. A sag in particular is one to price carefully, because a liner cannot correct it. See what a sewer line replacement involves if the scope points that way.

### Three example scopes

These are made-up examples to show how the reading works, not real homes.

Scope one. The camera shows a clay line, aligned and round, with fine roots at two joints. The inspector notes no cracks. This is the maintenance case. Ask the seller to have the line cleaned before closing, keep the video as your baseline, and budget for a cleaning now and then.

Scope two. Roots at three joints, plus one joint that has slipped out of line where the pipe passes under the driveway. Cleaning will clear the roots this month, but the offset gives them a permanent doorway. Get a written repair quote, because that number is what you take to the seller.

Scope three. The camera stops partway down the line and cannot go further. That is a blockage, a collapse or a bad offset, and you do not know which. Do not close on it. Ask for the line to be cleared and re-scoped, or for a price adjustment that assumes the worst case.

### What a seller's cleaning receipt does and doesn't tell you

A receipt from a recent drain cleaning shows the line was blocked at some point. It does not show the pipe is sound. Roots return unless the opening they used is sealed, so ask for the scope video from after the cleaning, not just the invoice. Our page on whether hydro jetting keeps tree roots from coming back explains why.

Clay is not the only old material a scope can turn up. San Luis Obispo describes Orangeburg, a bituminized fiber pipe, as commonly used from 1948 into the 1970s, and as almost impossible to maintain because mechanical rooters tear the pipe during cleaning. It lists cast iron at an average lifespan of 30 to 50 years, with rust and corrosion setting in naturally. PVC and ABS, the modern plastics, are generally impervious to roots at the joints when installed correctly. Ask the scope inspector to name the pipe material on the video. If it is Orangeburg, treat it as a replacement candidate rather than a maintenance item.

1. 1Order the scope. InterNACHI notes a sewer scope is not required by its standards for a home inspection, so it is usually a separate add-on. See should you get a sewer scope before buying.
2. 2Do it early. Schedule it inside your inspection period, early enough to renegotiate if it finds something.
3. 3Get the video, not just a verdict. Look for marked locations of roots, cracks and sags, and the pipe material.
4. 4Get a repair quote for anything beyond light roots. A written estimate from a licensed plumber turns "there might be a problem" into a number the seller can react to.
5. 5Choose your ask. The usual options are that the seller repairs it before closing, the seller gives you a credit toward repairs, or the price comes down.
6. 6Look at the yard. Find the cleanout, and note any large trees or oleanders near the line. Phoenix advises against planting a tree or large shrub near the line or cleanout, and the yard you are buying may already have broken that rule.

The line is yours. In Phoenix, the owner is responsible for the sewer line out to the city main, and the city does not inspect private sewer lines. The one exception covers broken pipe in the public right-of-way at single-family and duplex homes. See who is responsible for the sewer line in Phoenix. To learn what roots look like from the inside, read signs of tree roots in a sewer line, and for a routine that keeps a root-prone line running, see how to maintain your sewer line to prevent backups.

HQ Plumbing offers free estimates and upfront pricing on repairs a scope turns up, so you can weigh the fix before the inspection period runs out.

If the yard has mature trees, how roots destroy pipes in Mesa and Chandler yards shows how far roots reach and how to read the risk.