How do tree roots get in to the sewer pipe?

In order to survive, trees need water, nutrients and oxygen. If they don’t have enough of any of these, their roots go searching for them. Unfortunately for our homes, sewer lines provide tree roots with exactly what they’re looking for, water, fertilizer and oxygen.
The easiest way for a tree root to infiltrate a sewer line is if there is a brake in a line or pipe. Once these cracks in the line are found by a root it will send a signal to the tree that it found water, nutrients and oxygen. Once a tree root has penetrated a pipe, it will continue to grow into the pipe and get thicker and longer.