Uninvited Guests: Tree Roots in Your Sewer Line

Picture this… The day has finally arrived! Your parents are visiting your home for the very first time, and you’re eager to show it off. You’ve spent hours getting everything just right—mowing the lawn, mopping floors, and polishing the windows until they sparkle. Dinner is underway when, suddenly, a strange, foul smell rises from the basement. You rush down, hoping it’s nothing serious, but the sight that greets you is worse than you imagined: murky water spilling across the basement floor. Your heart sinks as you realize your plumbing is backing up. What do you do now? This is not the first impression you had in mind for your parents.

You plug in your brand-new shop vac and start vacuuming up the mess when the doorbell rings—it’s your parents! You rush to let them in, and they gush over your beautiful new home. But then your dad catches a whiff of the odor. Instantly, he’s in full Mr. Fix-It mode and heads straight for the basement.

Despite the circumstances, you’re relieved to have someone experienced by your side. Dad suspects a clogged drain and asks if you have a drain snake. You quickly realize you’re short on tools for a job like this, so you decide it’s time to call in a plumber. Thankfully, your neighborhood plumber arrives promptly and gets to work. After inspecting the plumbing and taking a look around your yard, he decides to send a camera down the line. As he rules out the usual culprits, the real troublemaker finally comes into view: tree roots in your sewer line! You’re shocked, thinking, “How could tree roots cause this?” But as the plumber explains, it’s actually a surprisingly common problem.

How Do Tree Roots Grow in Sewer Lines?

Tree roots in sewer lines are a common—and stubborn—problem for many homeowners. Unseen beneath the surface, roots can gradually infiltrate the sewer line, eventually leading to significant plumbing problems. Multiple factors contribute to the growth of tree roots in sewer lines, from the initial sewer line installation to everyday landscaping practices.

1. Installation Challenges: Pitch, Proper Support, and Soil Settling

During the initial installation, sewer lines need a careful setup to ensure long-term stability. Pipes should be laid with a slight pitch, meaning one end is slightly higher than the other to allow waste to flow naturally toward the main sewer. However, if the trench is uneven or isn’t supported adequately, the pipe can settle irregularly over time. Sometimes, installers dig too deep and overfill the trench, leaving voids or weak spots under the pipe. As the ground settles, these weak points can cause the pipe to shift, bend, or even crack. These small cracks may seem insignificant initially, but they create an easy entry point for tree roots seeking water.

2. When Landscaping and Sewer Lines Collide:

One often overlooked factor in sewer line issues is landscaping, especially when homeowners or landscapers plant trees without any awareness of the location of underground pipes. Landscaping plans and plumbing installations are rarely coordinated, so it’s not uncommon for a tree to be placed directly above or near a sewer line. As trees grow, their roots naturally spread out in search of nutrients and water. Sewer lines, especially those with small leaks or cracks, can act as a reliable water source, drawing roots toward them. Over time, these roots can penetrate even small openings, causing obstructions or further cracking the pipe.

3. Aging Pipes, Cracks, and Root Intrusions

Even the sturdiest pipes can develop cracks over the years, especially under factors like soil pressure, shifting ground, and temperature changes. Homes over 50 years old typically have clay sewer lines, which come with a lifespan of just 50–60 years, meaning replacement may be on the horizon. As these pipes age, small cracks can form, releasing moisture into the surrounding soil.

For tree roots, this moisture is an open invitation. Roots are constantly seeking water, and they can detect the moisture from these cracks, following it until they reach the pipe itself. Once roots find an entry point, they can infiltrate the pipe, expanding within it as they grow and creating serious blockages. Left unchecked, this root invasion can escalate, leading to significant disruptions in the sewer line.

Removal and Repair Options for Tree Roots in Sewer Lines

Several methods are available to remove tree roots in sewer lines. Each approach varies in effectiveness and cost, and some serve as temporary fixes while others are more permanent solutions.

Chemical Root Killers
Chemical root killers are a DIY option for treating root intrusions and are inexpensive, generally safe for pipes, and easy to use. These products remove the blockage by killing the roots that have entered the pipe. Chemical treatments require regular maintenance applications every 4–12 months to remain effective. While they don’t harm the plumbing, they don’t resolve the structural issues either, leaving the pipe vulnerable to future invasions if cracks are present.

Mechanical Auger/Snaking
Using a drain cleaning tool like a mechanical auger, or snake, is a quick way to remove roots and clear minor obstructions in the sewer line. This method can be effective in the short term, especially for smaller intrusions. Sometimes snaking doesn’t remove all root material, and regrowth is likely, as the cracks or openings remain unaddressed. Snaking in this scenario also carries risks because if the snake gets stuck, it can end up making the problem worse and may require a professional sewer line excavation to retrieve it.

While this is a potential DIY option, it is usually best left to an experienced plumber. And, like chemical root killers, snaking is a temporary fix that does not fix the crack in the pipe. It will only be a matter of time before roots make their way into the pipe again.

Hydro jetting
Hydrojetting is another temporary solution in which a trained plumber utilizes high-pressure water to clear tree roots in the sewer line. While this method effectively removes roots and other blockages, it doesn’t address the underlying issue: cracks in the pipe that allowed the roots to enter in the first place. Without further repairs, roots are likely to return over time, as they will continue to seek out moisture through any available openings.

Sewer Line Repair/Replacement
Sewer line repair or replacement is the most sure-fire method to prevent tree roots in a sewer line. This involves digging up and removing the damaged section of the sewer line and replacing it with new piping that roots cannot penetrate. Typically, pipe replacement can take 1–3 days to complete, depending on yard layout, depth of the line, and the presence of landscaping or other structures. 

Plumbing costs for tree root removal or pipe repair/replacement range from around $5,000 to as much as $25,000, depending on the extent of the work and the conditions of the property. Some home insurance policies may cover a portion of the expense depending on the specifics of the policy and the nature of the damage, but few policies cover all of the expense. Learn why sewer line replacement is so expensive.

Don’t Let Tree Roots Grow into Major Problems.

If you suspect that tree roots are causing backups or slow drains in your home, it’s best to call a professional. A trained plumber can assess the situation, identify the cause, and recommend the most effective solution. Don’t wait until the problem grows!

Need sewer line repair in Jessup, MD? Our Howard County pros are prepared to assist. In Charm City? Our team specializes in sewer line repair and replacement in Baltimore County. For those closer to D.C., we’re also available for sewer line repair in Rockville, MD and the surrounding area.