Tree Roots and Your Sewer Lateral

Why it matters

Your sewer lateral is the buried drain linking your home to the municipal sewer under the street. In Burlington, the part on your property is generally the owner's to maintain. Older laterals were made of clay tile or cast iron in short sections joined end to end. Over decades, those joints shift a little, and moisture and nutrients seep out. Tree roots sense that and grow toward it. A hair-thin root can enter a joint, then thicken and branch inside the pipe, catching paper and grease until the line clogs.

Neighbourhoods with big, mature trees, such as Roseland, Shoreacres and the streets near downtown, see this problem most often.

Step by step

1. Watch for early signs. Gurgling toilets, slow drains on the lowest floor, or water at the basement floor drain after laundry are typical.
2. Avoid heavy use when it starts. Postpone laundry and long showers until the line is cleared.
3. Have the line cleared. A cable with a cutting blade restores flow. Hydro jetting scours fine root hair more thoroughly.
4. Look inside. A camera inspection pinpoints root entry and any cracking, shifting or caving.
5. Decide on a plan. If the pipe is sound, periodic cleaning can be enough. If it is broken, sewer line repair or lining is the lasting fix.

Common mistakes

• Pouring root-killing chemicals in without knowing the pipe's condition
• Waiting until sewage appears in the basement before calling
• Planting new trees, especially willows and silver maples, close to the lateral's path
• Paying for annual cleaning without once seeing inside the pipe

Also remember that roots love a pipe that already carries grease and wipes. Our letter on what not to flush helps keep the line clearer between cleanings.

When to call a plumber

Call when more than one fixture slows down, when the floor drain backs up, or when you have had the line cleared more than once in a year. If you are buying an older home with large trees in front, ask for a camera inspection before closing. A clear recording of the lateral is one of the most useful documents an owner can have.

Choosing trees with the lateral in mind

If you are planting, find out where the lateral runs first, usually in a straight line from the front basement wall toward the street. Keep large, thirsty species well away from that line. Smaller trees with less aggressive roots are a better fit near the path of the pipe.