Most people only think of drain cleaning when the shower drains slowly or the kitchen sink won’t empty. The truth is if you live in a single family home in an established neighborhood you may want to consider having your sewer line cleaned periodically even if you aren’t having trouble.
Sewer line is laid in sections and a tree root will find it’s way between the sections and begin to grow in the line. The items traveling through smaller lateral lines (toilet paper, kitchen disposal garbage, etc) will eventually reach the roots in the sewer line and get hung up on them and a stoppage is formed over time.
By having those tree roots cut out once a year, you can help prevent an unexpected and damaging major sewer line back.