Does Root Killer Work?

Hey everybody, Mitch with Smedley Plumbing here, and today’s question of the month in our little video series here is going to be, does root killer work?

We get this question quite a bit as we’re augering sewer lines. It’s kind of a loaded question. They’ve got chemicals available at your local hardware stores and home improvement stores that advertise themselves as root killers. You can put them down your toilet or flush them down your drain, and they will kill the tree roots that are getting into your sewer line. By definition, they do kill the roots; however, they don’t necessarily work all that well at keeping your drain line flowing free and clear. Let me explain.

does root killer really work

How Do Tree Roots Grow in Your Sewer Line

Homeowners must understand that tree roots invade a sewer line through the joints, any cracks in pipe walls, and especially the top of a sewer line. Tree roots are very resourceful in finding the nutrients they need for root growth. This causes many homeowners common tree root problems because most main sewer lines and plumbing systems run underground, typically underneath a tree. The growing tree root system will find its way into any joints or openings your sewer line may have. Once the root has entered your sewer system, restoring any root control can be expensive.

The root intrusion will grow over time if left untreated and will slowly start to compromise the drain line flow. Causing your plumbing systems to become clogged and backed up, and a very expensive fix. Homeowners typically have root growth issues for older homes that use clay pipes because clay pipes are not as durable as PVC drain pipes are for modern homes. Unfortunately, septic systems are also susceptible to root problems, especially if a septic tank becomes compromised because of new root growth.

Below is a picture demonstrating tree roots’ extensive growth within a drain pipe. The roots start from the top and will slowly work their way to the bottom, and that’s when homeowners begin to notice issues. Tree roots catch and collect all of the toilet paper and waste that is supposed to be flowing, eventually causing a backup in your plumbing system.

tree roots in sewer line

Root Killer Products

If you’re a homeowner attempting to DIY your root problems thinking you’re a tree root killer, it’s good to know how root killer products actually work.

When root killer for sewer lines are poured down a drain line, it only flows along the bottom of the pipe. Most root killers don’t flow very well along the top of a drain pipe. As mentioned above, root growth begins at the tops of most pipes and makes its way to the bottom. The root-killing solution will come into contact and kill the bottom layer of root growth, but this will not completely restore your sewer line flow. A tree root killer could help for a quick solution, but it is not the answer to the bigger problem.

If you plan to use root killers, it’s important to understand the different types of root killers and how they can affect the tree roots and your drain pipes.

The most common root killer available for consumers is those with copper sulfate solutions. Copper sulfate is made from copper compounds and sulfuric acid. Copper sulfate is a traditional drain cleaner type of product that is used when tree roots begin to affect sewer systems and obstruct drain pipes. Other chemical root killer chemical solutions such as dichlobenil not only kill roots but helps to prevent new roots from growing due to their corrosive properties. Dichlobenil is combined with other chemicals, such as metam-sodium, that act as a contact herbicide. Meaning it only works when it comes in contact with the tree root. RootX is a product that uses the dichlobenil root-killing method. Another type of root killer is the foaming tree root killer compound. A foaming root killer will self-foam once it comes into contact with water, and when it comes into contact with a root, it will stick to it. When the foaming root killer properties attach to the tree root, the solution quickly eliminates many of the roots. Roebic is a common product that uses the foaming tree root killer method. Both Rootx and Roebic chemicals can be found at stores such as Home Depot and Amazon, or whichever place has similar chemicals.


root killer

Signs You Have Tree Roots in Your Pipes

There are several signs to watch out for that can indicator you have root damage.

Slow-Moving Drains

Slowly moving drains are the typical first indication of root problems with your sewer line. If you notice that your toilet drains slowly or makes gurgling sounds when you flush, roots have most likely invaded the drain pipes. If you have an older home with clay pipes or have mature trees on your property, there is a higher risk for tree root problems. Learn more about our expertise on clearing Clogged Drains.


Sinkholes are common in some sections of the nation. However, they are also an indication of major root damage to drain pipes. As a homeowner, it’s best not to go near any obvious sinkholes in your yard. Call a licensed plumber to investigate the problem and assess the situation. A plumber can indicate if the issue is a potential risk for your home’s foundation and will assist in providing the best solution.


cutting roots out of sewer line

Blocked or Collapsed Pipes

Backed-up toilets are a major annoyance. However, if the issue is related to roots in your pipes, you might wish the problem was caused by something your kids flushed down your toilet. The truth is root obstructions are one of the most common reasons for clogged pipes. This problem will not go away with the help of a professional plumber.

Foul Odors

Tree roots cause havoc on sewage pipes, causing them to clog. If not caught, the pipes can collapse. If you notice any foul odors both inside and outside the property, such as the smell of rotten eggs, you may have a major blockage.

You Should Call Smedley

The best root killer is actually having a plumber come out. A plumber can manually cut those roots out of the line with hydro jetting and will stop them at the source. Plumbers can also run cameras down the sewer line and verify if it is just a simple root stoppage or if there is a much bigger problem. The over-the-counter root killer products, by definition, do kill roots. However, once we look at the nature of how a sewer pipe lays in the ground and where the water is in that pipe, they don’t really do a good job of getting rid of the roots in your sewer line.

Learn more about our Sewer Piping Service!