How to Kill Roots in Sewer Lines

Tree roots can find the smallest of crevices in the sewer line and work their way inside. Some people pour salt into their sewer lines, but this not only kills the tree roots, it will also kill the tree. You can hire a professional plumber to snake the line, this is only a temporary solution. You can easily do the job yourself by using copper sulfate in one of two ways. You can apply it to the soil or dump it down the toilet drain. You will only be forcing the tree roots to grow in another area. Your sewer line will be clear, and the trees will still live.

Things You'll Need

• Flag
• Chalk
• Earth auger to drill a 2.6-inch diameter hole
• 1.5 PVC pipe
• Glue
• Female adapter
• Copper sulfate
• Hot water

Instructions

Killing Tree Roots Outdoors

1. Find your sewer line. You will need to know where the line is and how deep it is beneath the ground. If you don’t know where it is, then contact the city office. They will have the information you need. Call the electric, cable and gas company to make sure that none of their lines is in that area.

2. Place a flag where your line connects to the city line and where it comes out of your house. You can use chalk to mark a straight line so you will know exactly where the pipe is located.

3. Rent an earth auger and drill a 2.5-inch-diameter hole in the ground, stopping 24 to 30 inches above the sewer line.

4. Cut a 1.5 PVC pipe the same length as the hole you just drilled. Glue a female adapter onto one end of the 1.5 pipe and insert the other end into the hole you just dug. The pipe should fit flush with the ground. If it doesn’t, you will have to remove the pipe and cut it to the right length.

5. Pour 4 pounds of copper sulfate into the pipe. Buy small- to medium-sized copper sulfate.

6. Pour 5 gallons of hot water down the pipe to help dissolve the copper sulfate into the ground.

7. Reapply the copper sulfate every four months to keep tree roots away. This is not a fast solution. It can take a month or more before the tree roots leave the area.

Killing Tree Roots from the Inside

1. Pour ½ cup of copper sulfate into the toilet. Buy medium-sized copper sulfate in a 2-pound box. Do not pour it down any other drain other than the toilet because copper sulfate can eat through metal pipes.

2. Flush the toilet.

3. Pour another 1/2 cup of copper sulfate into the toilet and then flush again. Keep repeating this method until you have used all but a half cup from a 2-pound box.

4. Take the last half cup of copper sulfate and pour it into the toilet bowl. Do not flush. Leave it in the bowl overnight. Flush the toilet in the morning.

5. Reapply copper sulfate every six months.

References

• City of Indianapolis Department of Public Works: Trees and Sewer Conflicts
• Pipe Doctor USA: 5 Steps to Dealing with Invasive Tree Roots
• Ask The Builder: Avoiding Sewer Back Ups From Tree Roots
• Eco-nomic: Controlling Tree Roots in Sewer Lines with Copper Sulfate
• Drains and Plumbing: Sewer Drains and Cleaning Tree Roots

Resources

• Read this Article in Spanish