Tree Roots in Sewer Line: Copper Sulfate Treatment

Clearing Roots from Sewer Pipes with Copper Sulfate

A homeowner has tree roots blocking the sewer drain, causing basement backup. They want to kill the tree and root system.

Killing the Tree Is Not the Solution

If roots have fully blocked the line, the pipe is already compromised. Killing the tree leaves dead roots in the pipe and doesn't fix the plumbing. The priority is clearing the blockage.

Copper Sulfate Root Treatment

For slow-flowing (not fully blocked) drains, copper sulfate kills roots inside pipes without harming the tree.

Procedure

1. Flush ½ cup copper sulfate crystals down the toilet.
2. Repeat until 2 lb container is empty.
3. Flush several more times to push crystals into the sewer line.
4. Vacate house for several hours (fumes).
5. Monitor flow for days/weeks—roots die slowly, then decay and wash away.
6. Repeat every 3–4 months with smaller doses for maintenance.

If Fully Blocked

Call a plumber for mechanical clearing (auger, hydro-jet). Then start copper sulfate maintenance. Consider pipe lining or replacement for permanent fix.

Tree Health

Copper sulfate at label rates kills only roots in the pipe, not the tree. The tree survives.