Everything to Know About Tackling Tree Roots in Sewer Lines

Tree roots in sewer lines may be out of sight, but they won’t be out of mind for long. Find out how to identify this issue and how to resolve it.
Melissa Graham Avatar
Tree Roots In Sewer Line

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What You Need to Know

  • Tree roots naturally grow into sewer lines as they are a source of additional water and nutrients.
  • Some signs of tree roots in sewer lines are sinkholes, soft spots in the yard, slow drains, gurgling toilets, and rapid tree growth.
  • If left untreated, tree roots in sewer lines can wreak havoc on a home’s plumbing system as well as its lawn and foundation.
  • There are some commercial tree root killers for DIYers to tackle this issue on their own, but it’s generally best to let a plumber remove the tree roots and make any repairs.

Q: There’s a sinkhole starting to form in my yard. My neighbor had a similar issue a few years ago, and it ended up being tree roots in the sewer line. Could I be having the same problem? What should I do? 

A: Trees on your property provide beauty, value, and homes for wildlife. But many homeowners may not consider that tree roots can wreak havoc on the pipes that run near and under your property. Tree roots in sewer lines can cause severe issues in your home, including sinkholes, gurgling toilets, and slow drains.

You’re probably wondering how to clear roots from drain pipes. Thankfully, many homeowners will be able to solve this problem independently with some homemade root killer for sewer lines. But it may be easier to opt for help from one of the best plumbing services like Mr. Rooter or Roto-Rooter, especially if the problem seems beyond your capabilities or expertise.

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Tree roots grow toward and into the sewer line for moisture and nutrients.

How do tree roots grow into sewer lines in the first place? In the search for moisture and oxygen, roots grow toward and tend to penetrate tiny cracks in sewer lines to tap into excess nutrients. If a yard has many trees, especially ones that are mature or oversized, this could present a problem. A slight infiltration can lead to a significant blockage that damages the home’s plumbing as well as the yard or foundation. Plus, a tiny crack in the pipe can give roots in sewer lines more consistent moisture, leading them to expand to fill the pipe and cause more damage.

Signs of tree roots in a sewer line include sinkholes in the yard, slow drains, gurgling toilets, and fast tree growth. 

Because sewage and water pipes are located underground, tree roots can grow right through them, causing leaks and other issues that could result in significant damage. One sign that tree roots are blocking the sewer line is the presence of soft or saturated spots in the yard. When tree roots grow into plumbing, it can cause water to leak into the yard and create a sinkhole. Sinkholes are a risk for trips and falls, especially if there are kids playing in the yard, so it’s a good idea to call a professional to repair a sinkhole as soon as possible. A professional can also verify that tree roots in the sewer line are causing this problem. If it’s a simple drainage issue, it may be necessary to regrade the lawn or install a French drain instead.

Other signs of tree roots in a sewer line are slow drains or gurgling toilets. If it seems like all of the drains in the home are slow even after using a drain cleaner or that more than one toilet in the house is gurgling, the sewer line could have a leak. If these issues are not present but one tree in the yard is growing faster than others, it may be because it’s receiving more moisture than other trees on the property because its roots have grown into the sewer line.

Tree Roots In Sewer Line

It may be possible to eradicate minor tree root growth in a sewer line using some DIY solutions. 

For those who are interested in learning how to kill tree roots that are interfering with sewer lines themselves, it’s best to research the best root killers for sewer lines rather than picking up a random tree root killer from Lowe’s or The Home Depot. So what dissolves tree roots in sewer lines? Rock salt is available at most hardware stores and is a popular solution to suck moisture from roots and kill them. Slowly flushing about 2 pounds’ worth down the toilet often does the trick. Afterward, it’s important to let the rock salt seep into the roots for about 12 hours without running water or flushing toilets.

Foaming root killer is another DIY root-killing option. This solution kills roots in the sewer line and prevents roots from growing back and causing more blockage. This substance is easy to use and only needs to be poured into the toilet and flushed. Copper sulfate is another sewer root killer that users can flush down their toilets to eliminate roots in drain pipes. However, the chemicals in copper sulfate are dangerous to dogs and are even banned in some areas, so it’s best to check local legislation to see if it’s acceptable to use.

Calling a professional is the best way to get tree roots out of the sewer line and repair the damage. 

It may be tempting to save a few bucks by using a DIY method to kill roots in a sewer line, but a professional plumber can much better handle this issue. Plumbers have the skills and experience to identify the problem. After all, it may turn out that the clog is not caused by tree roots. In this case, a plumber or one of the best drain cleaning services will know how to unclog a sewer line quickly and efficiently. Plumbers also have the proper tools and methods that go beyond applying a commercial root killer for sewer lines. For example, they may be able to repair the pipe using a cured-in-place pipe lining, which involves inserting a liner inside of a sewer line where it has sustained damage. This method essentially restores the pipe to near-new condition and prevents future root infiltration without the need for trenching.

Although paying for a plumber may be more expensive up front, the investment will likely pay off in the long run. Effectively and promptly killing tree roots and repairing the sewer line can prevent more severe damage in the future.

In the course of finding out who to hire to remove tree roots in a sewer line, it’s reasonable to wonder whose responsibility it is to repair: the homeowner, the city, or the utility company. In some cases, such as if the tree roots have grown into the sewer main, the municipality will pay for repairs to the main. Homeowners may also wonder if tree roots in the sewer line are covered by insurance. Unfortunately, homeowners insurance is not likely to cover this issue.

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An annual plumbing inspection can keep tree roots from infiltrating pipes in the future. 

Roots in pipes are no small problem, so it’s important to get ahead of them. An annual plumbing inspection can go a long way in providing peace of mind and preventing major damage before it starts. Professional plumbers have cameras they can put through pipes to identify and remedy any potential problems. Tree roots in a sewer line can cost a pretty penny to resolve, and if the damage is severe enough, sewer line replacement costs $1,253 to $4,701. Annual inspections not only catch problems before they arise but also ensure the pipes stay clear after the removal of the roots is done. Plumbers can provide tips and tricks for keeping plumbing in tip-top shape, from the dos and don’ts of French drain cleaning to proper maintenance.

Planting new trees away from sewer lines and opting for “sewer-safe” trees can prevent future tree roots in the sewer line.

Preventing tree roots in the sewer line in the first place is much easier than removing roots from drain pipes after the damage is done. If any landscaping work is being planned, it’s important to think carefully about tree placement as it relates to sewage lines in the yard. Professionals recommend planting trees a minimum of 10 feet away from the sewer line. Some trees are also considered to be “sewer-safe,” as they grow relatively slowly and have more manageable root systems. Some examples of sewer-safe trees are cypress, flowering dogwood, and Amur and paperbark maples. By contrast, sycamores, cottonwoods, and aspens have more aggressive root systems, so it’s best to plant them far away from sewer lines.