Tree roots are one of the most common causes of sewer line blockages and damage. As they seek out moisture, roots can infiltrate small cracks or joints in your sewer pipes, growing and expanding over time until they create serious plumbing issues. If left unchecked, they can cause slow drains, backups, and even complete pipe failure requiring extensive sewer repair.
How do tree roots get into sewer pipes?
Tree roots seek out water sources below ground
Tree roots naturally seek out water sources below ground through a process called hydrotropism. Since trees need moisture for survival, they send out roots out in all directions, searching for moisture and nutrients. These roots are extremely sensitive to any bit of moisture in the ground, and can detect the tiniest change in soil moisture levels.
Even the tiniest leak will attract roots
Tree roots are so sensitive to moisture that even the tiniest pinhole or hairline crack in a sewer line can attract their attention. As water seeps from a tiny crack or loose joint in the pipe, it moistens the surrounding soil, creating a beacon for nearby roots. This moisture draws roots towards the source, where they locate the opening in the sewer pipe and begin to infiltrate and force their way in to access the life-giving water and nutrients.
The process of root intrusion often starts slowly, with fine root hairs entering through minuscule openings. However, as these roots grow and thicken, they can cause significant damage to the pipe structure. The continuous growth and expansion of roots can lead to blockages, reduced flow, and even complete pipe collapse if left unchecked.
Old cast iron and clay pipes fail over time
Older sewer systems, particularly those constructed with cast iron, clay, or even Orangeburg pipes (the worst!) are more susceptible to root infiltration as they age. Over time, these pipes naturally weaken and develop cracks, loose joints, and other vulnerabilities that provide entry points for tree roots. The porous nature of clay pipes also makes them especially prone to root penetration, as roots can actually grow through the material itself.
Shifting ground can cause cracks in any type of pipe
The dynamic nature of soil movement means that even structurally sound pipes can suddenly become vulnerable to roots. Ground movement, whether due to natural settling, seismic activity, or nearby construction, can cause damage to sewer lines. Shifting ground can lead to the development of cracks, misalignments, or separations in the pipe joints. These newly formed openings suddenly create pockets of moisture in the ground and provide perfect entry points for opportunistic tree roots seeking moisture and nutrients.
How do you know if you have tree roots growing in your sewer line?
Slow drains or regular backups
One of the most common indicators is slow drains or backups in your plumbing system. If you notice water draining slowly or completely backed up – especially from multiple fixtures or drains – it could be a sign that tree roots in my sewer line are causing blockages.
Roots pulled back when snaking a backup
Sometimes our plumbing technicians are called out to snake a backed up toilet or sewer, and they will literally pull out roots when they pull the snake back. This is obviously a pretty good indicator that there are tree roots have infiltrated the line and are contributing to the drainage problem.
Sewer camera inspection
A sewer camera inspection is the most effective method to detect roots in your line. This process involves inserting a specialized camera into your sewer lines to visually inspect the interior of the pipes.
If tree roots are present, not only will they be clearly visible to the video screen, but the technician will be able to determine their location in the pipe and determine the best method to clear them and prevent their return.
Methods to Get Rid of Roots in Sewer Drain Pipes
Mechanical tree root removal using a cutter, chain, or “rooter”
Mechanical removal, often referred to as “rootering,” is a common method for addressing tree roots in sewer lines. The process involves inserting a specialized tool into the pipe that cuts and removes roots obstructing the flow. The rooter or cutter typically consists of blades or chains that rotate at high speeds, slicing through the invading roots and clearing the pipe. This method is useful for immediate relief of blockages and restoring proper flow in the sewer line.
But while rootering can provide quick results, it’s important to note that it is only a temporary solution. Not only will the roots grow back, but they will usually grow back even more vigorously. And every time they breach the pipe, they will further damage it and eventually destroy its structural integrity.
So once you use mechanical rooting to remove tree roots, you’ll probably need to do it at least annually, and in the meantime, it will further damage your sewer pipe, which will eventually need to be replaced.
Hydrojetting
Hydrojetting is another effective method for removing not only tree roots, but just about anything that is blocking your pipe. This process is essentially a high-volume pressure washer that can completely remove tree roots, scale, and grease, and restore the pipe to its full diameter.
Hydrojetting is generally more expensive, however, as it requires specialized equipment, technicians, and a lot of water, so we usually don’t recommend it tree roots are the only problem in the line.
Sewer Patch with CIPP or excavation
Sewer patching using Cured-In-Place Pipe (CIPP) technology or traditional excavation methods are effective solutions for repairing localized damage caused by tree roots.
CIPP involves inserting an epoxy-resin-saturated liner into the damaged section of the pipe, inflating it to the proper diameter and then hardening it with a curing method, creating a new pipe within the old one. This trenchless method can effectively seal cracks and joints, eliminating root problems without the need for extensive digging. CIPP patching is particularly useful for addressing specific problem areas in the sewer line while minimizing disruption to the surrounding landscape.
At Service Force, we use the latest Ultraviolet-light-cured technology to cure our CIPP patches. In our experience, it is much faster and more reliable than the older, heat-cured methods used by other plumbers.
In cases where CIPP is not suitable or the damage is too extensive, traditional excavation may be necessary. This method involves digging down to the affected pipe section, removing the damaged portion, replacing it with new piping material – usually PVC – and surrounding it with the proper support with gravel and soil compaction.
Both CIPP and excavation methods not only repair existing damage but also prevent any further root intrusion by creating a barrier that roots cannot penetrate, providing a long-term solution to root-related sewer line issues.
Sewer Replacement with CIPP, Pipe Bursting, or excavation
When tree root damage is extensive and the sewer line is severely compromised, full replacement may be necessary. There are several methods available for sewer line replacement, including trenchless options like CIPP (Cured-In-Place Pipe) lining and pipe bursting, as well as traditional excavation.
Our UV-cured CIPP trenchless technology described above can be used for full replacement as well as patching, and we have another trenchless method called “pipe bursting” that involves breaking the existing pipe while simultaneously pulling a seamless, completely new pipe into place.
Traditional excavation, while more disruptive, may be necessary in some cases where the condition of the pipe is so bad that trenchless is not an option.
Regardless of the method chosen, full sewer line replacement offers a comprehensive solution to root invasion problems, providing a new, root-resistant pipeline that can significantly extend the lifespan of the sewer system.
Apply Chemical Tree Root Killer
Chemical root destroyers are sometimes used as a method to control tree root growth in sewer lines. These products typically contain herbicides or growth inhibitors that are flushed into the sewer system to kill existing roots and prevent new growth. While chemical treatments can be effective in the short term, they are generally not recommended as a long-term solution. These chemicals can be harmful to the environment, potentially contaminating groundwater and affecting beneficial soil organisms. Additionally, they may damage the sewer pipes themselves, especially older or already compromised lines.
The use of chemical root destroyers also raises concerns about their impact on wastewater treatment plants and the broader ecosystem. Many municipalities restrict or prohibit the use of these products due to their potential negative effects.
Furthermore, while chemical treatments may (or may not) successfully kill roots and prevent regrowth, they do not address the underlying issues that allowed roots to enter in the first place, such as cracks or joint separations. For these reasons, professional plumbers usually don’t recommend chemical root destroyers and instead suggest more sustainable and effective long-term solutions for managing tree root problems in sewer lines.
Apply Rock Salt
Applying rock salt to sewer lines as an old technique that you’ll still see recommended for controlling tree root growth is an old technique. The theory behind this method is that the salt creates an inhospitable environment for root growth, deterring roots from entering or growing within the pipe. However, like chemical root destroyers, the use of rock salt is not recommended by professionals due to several significant drawbacks. Salt can be corrosive to pipe materials, potentially exacerbating existing damage or creating new vulnerabilities in the sewer line. Additionally, the salt can leach into the surrounding soil, affecting not only the targeted tree roots but also other plants and soil organisms in the area.
Conclusion
Dealing with tree roots in your sewer line requires a strategic approach. While mechanical root removal, hydrojetting, and chemical treatments can provide temporary relief, they don’t address the root cause (pun intended!). For a long-term solution, sewer repair methods like CIPP patching, pipe bursting, or full line replacement can eliminate root intrusion and prevent future problems. If you’re experiencing slow drains or recurring backups, call a proven plumber like Service Force Plumbing for the best advice and service for sewer maintenance, repair, and replacement.
Tyler Pittenger is an expert sewer and drain plumber at Service Force Plumbing, as well as a master of customer service. He has been used as a source for national publications like BobVila.com, FamilyHandyman.com, and HGTV.com.
FAQs
Q: How do tree roots get into sewer line pipes?
A: Tree roots are naturally drawn to the moisture and nutrients in sewer lines. They can enter through small cracks, joints, or deteriorated areas in the pipes. As the root system grows, it can expand these openings, leading to more severe tree root invasion and potential pipe damage.
Q: How can I prevent tree roots from entering my sewer line?
A: If you currently have an issue with roots in your sewer line, the best way to prevent entry is to either use a CIPP method to seal the pipe, or to replace the pipe. Sewer pipes that have no leaks are not vulnerable to tree root entry, so if your pipe currently has no issues, you should not be too worried about the problem.
Q: How much does it cost to remove tree roots from your sewer line?
A: The cost to remove tree roots from your sewer line can vary widely depending on the extent of the invasion and the method used. Simple root cutting may cost $300-$600, while more extensive treatments like pipe relining can range from $3,000 to $25,000. It’s best to get a professional assessment and several estimates to determine the most cost-effective solution for your specific situation.
Q: What methods are used to remove tree roots in pipes?
A: Several methods can effectively remove tree roots from your sewer line, including mechanical augers, high-pressure water jetting, chemical treatments like foaming root killers, and pipe relining. In severe cases, excavation and pipe replacement may be necessary. The best method depends on the extent of root invasion and the condition of your pipes.
Q: Can I use chemical treatments to kill tree roots in my sewer?
A: Chemical treatments like copper sulfate or foaming root killers can be used to kill tree roots in your sewer. However, these should be used cautiously as they can harm the environment and will not solve the underlying problem – openings in your pipe. It’s best to consult a professional plumber before attempting chemical treatments to ensure they’re appropriate for your situation.
Q: How can I prevent tree root damage to my sewer line in the future?
A: Ultimately, you need to repair or replace the sewer line to eliminate any openings. As long as there are cracks or holes in your sewer pipe, tree roots will find them and enter. Even if you cut them out, each time they return they will worsen the damage to the pipe
Q: What are the risks of ignoring tree roots in my sewer line?
A: Ignoring tree roots in your sewer line can lead to severe consequences, including complete pipe blockages, sewage backups into your home, pipe collapse, and extensive property damage. It can also result in health hazards due to exposure to raw sewage. Tackling tree roots early can prevent these issues and save you from costly repairs in the long run.
