How To Kill Tree Roots Clogging a Sewer Line
Tree roots can clog or even break apart sewer drain lines. The tree roots primary function is to find water and nutrients to feed the tree. They grow outward, hunting for moisture. Sewer lines tend to leak a bit at the seams and along the pipe where cracks and corrosion occur. The tree roots find that moisture and grow toward it with vigor. The new tendrils of roots are like tiny little fingers and grow into the crevices and openings in the sewer line. As they grow into openings in the pipe, they also grow in size, working like little crowbars to pry open the sewer line.
Once inside the sewer line, the tendrils hang down into the pipe. The roots also grow large and fill the pipe and reduce its volume. As more and more tree root growth occurs, the sewer line gradually becomes blocked. Even more serious is the destructive power roots have to tear open the line or to crush it closed.
When a home's sewer line backs up as a result of tree roots, there are few options. Typically a mechanical drain snake is used to clear the line. However, there are two levels of thoroughness that can be done here. Many plumbing services will open the line by drilling through the roots, but they don't spend the extra time to clear the all of the roots. Making multiple passes, with progressively larger cutting heads should be done to clear all the roots from the line. This will remove all of the restrictions in the sewer line and prepare it for the next step.
Once tree roots have been cleared out, they will promptly starting growing again. The next step in the battle is to keep them at bay with a product that will repel or kill the roots. The most commonly used product is copper sulfate. The material is poured down the drain and allowed to flow through the sewer drain where it comes in contact with the roots. It kills the roots, but doesn't harm the tree. According to some reports, you may be able to clear the roots without the use of a drain snake. However, you must have enough flow to allow for the flushing of a toilet, otherwise the copper sulfate will not make its way to the roots.
The instructions that accompany the copper sulfate will warn you that it is dangerous, should not be handled directly, to leave your home after flushing the crystals to avoid breathing the fumes (including evacuating all pets to the outdoors) and so on. Follow all of the manufacturers directions. Generally, the instructions will call for repeatedly flushing the crystals over a period of days and then using maintenance doses a couple times a year.
Some people feel that copper sulfate isn't sufficiently effective because it only flows along the bottom of the pipe and does little to fight the tendrils hanging down and the roots prying at the top of the pipe. Another product, Root-X, foams as it passes through the sewer line causing the active ingredient to make contact with the entire surface of the pipe along with all of the exposed roots.