Will Bleach Kill Tree Roots in a Sewer Line? Yes, But There’s a Catch…

Admit it – every time your pipes get backed up, you start thinking about all those things you flushed down the toilet (tissues, tampons, condoms, yuck) or how much hair you let into your shower drain the last time you shaved. However, although more than 50% of people flush the things they shouldn’t every once in a while, the reason behind the obstruction could be – tree roots.

And, once tree roots start invading your pipes, this problem can turn into a major one that requires immediate intervention. To make sure those nasty tree roots don’t get large enough so they can cause a massive obstruction, you will probably start thinking about products you can use to get rid of them. One of the things people use to kill roots in sewer lines is – bleach. Today, we are answering several hot questions, such as will bleach kill tree roots in a sewer line, what can I use to kill tree roots in my sewer line, and explaining why you might want to use other root killing products instead of bleach.

How Do Tree Roots Get Into Pipes?


Pipes installed in the 1970s or 1980s are very likely to have become rotten, tiny cracks and fissures have started developing, and pipe fittings have become loose. It takes a single crack for tree roots to start invading the whole piping system. Normally, tree roots can’t attack newer drain pipes.

Yet, what does make pipes so attractive to tree roots? Well, the sewer line is a place where there are both water and nutrients tree roots need to grow, and, as they do, they start looking for more nutrients, which makes them expand.

Keep in mind that you are not safe from tree roots coming from a tree that is around 25 feet away from your sewer line. What is more, the further the tree, the thinner the roots, which instantly makes it easier for them to get through tiny cracks into your sewer system.

Now that you understand tree roots are an issue that shouldn’t be neglected, let’s talk about the things you can use to kill tree roots in your sewer lines, one of which is bleach.

Will Bleach Kill Tree Roots in a Sewer Line?


If you apply bleach to a tree stump, you will kill it. Thus, if you apply bleach to tree roots, you will kill them as well, but not dissolve them. If you want to protect the tree but kill drain roots, the best solution is to cut the roots, then drill holes into each, and spray them with bleach. Note that a single application won’t necessarily do much. Instead, repeat the process two to three times and make sure to use a slightly larger amount of the product.

Why Killing Tree Roots Using Bleach Is Not a Good Idea…

At first sight, bleach seems like a budget-friendly solution for tree roots. However, similar to salt and lye, bleach has several drawbacks, and we will list the main ones below:

1. It Takes Multiple Applications

Bleach will rarely kill the roots after the first attempt. You will probably have to reapply it several times, which will kill the tree itself, as well as nearby plants as grass.

2. It Can Damage Your Pipes

Bleach, salt, and lye are highly corrosive, which means – you may want to stay away from them if your pipes are made of metal. Once the corrosion process is triggered, you will, highly likely, start experiencing further plumbing issues, which is why we don’t recommend using bleach.

If not pre-diluted with water, bleach can start burning the tree and the roots within 10 minutes only. Just in case you still want to go for this option, mix equal parts of bleach and water before applying it.

3. It Is Poisonous

Using bleach can get dangerous. If you don’t protect your eyes, nose, and skin, you may experience serious chemical burns or respiratory problems.

Now you see why using bleach for killing tree roots can get too risky, but you can still opt for a professional tree root killer that is 100% safe to use. Or, you can follow our recipes for homemade root killers!

What Else Can I Use to Kill Tree Roots In My Sewer Line?


There are multiple ways to kill tree roots in a sewer line, such as: using copper sulfate, rock salt, or bleach. The best thing is that you can try these solutions yourself, without calling a sewer line specialist or a plumber. The second best thing is that all of these products are quite affordable while still relatively efficient will killing tree roots. You can also use copper sulfate, rock salt, or bleach as preventative measures.

1. Copper Sulfate

If the tree roots in your sewer line are still small, you can use copper sulfate, the bright blue crystal to get rid of them. Simply pour half a cup of the product down the toilet and flush it several times. Copper sulfate can be found in home improvement stores.

However, copper sulfate can be harmful to plastic and old iron pipes while it is not septic-system friendly either. You can find the answer to the question are septic tanks bad in this blog. Also, we wrote a separate article about copper sulfate and its effects on tree roots.

2. Rock Salt

Rock salt [1] is definitely one of the most efficient things you can use to kill tree roots. However, it should be used with the utmost caution since it is poisonous and you can not only kill the roots but the tree itself and surrounding plants as well.

You are going to need 2 lbs of rock salt. Firstly, pour around a quarter of the whole amount into the toilet and flush it 2 to 3 times. Then, follow with the rest of the rock salt, which should do the trick. You can repeat the same process after around 2 weeks to make sure no living tree pipes are left in your sewer line.

3. Bleach

You have probably heard that bleach is one of the solutions to kill tree roots.

So, if you ask us – will bleach kill tree roots in a sewer line, we will say yes.

However, if you use bleach for killing tree roots, be extra cautious not to kill the tree itself along the way [2]. Bleach is a strong chemical solution that, similarly to rock salt can help you solve the problem but can cause another one. It would be best to use bleach to kill tree roots that have previously been cut off as well as for killing tree stumps.

Will Bleach Kill Tree Roots – Summary

Yes, bleach will kill tree roots since it is a super strong chemical. However, it is so strong that it can kill the entire root as well, which, probably, you don’t want. That is why it would be best to play it safe and use bleach only when the tree roots are already cut off. We have already mentioned a few other solutions for tree roots you can try that will help you kill those roots and make sure you keep your peace of mind (and your tree).