What are the common causes of a sewer line backup?

Common causes of a sewer line backup include tree root intrusion, grease buildup, pipe bellies (sags), cracks or deterioration, and debris obstructions. Roots are the most frequent issue because they enter joints and catch solids, which slows flow until waste reverses course. A belly acts like a low spot that holds water; sludge settles there and eventually chokes the line. When damage is present, the solution can range from cleaning to trenchless repair or, if extensive, full replacement. Our team often sees these patterns in homes around Centennial and confirms the exact cause with a sewer camera before advising next steps.

Typical next steps by cause:

• Roots or heavy grease: hydro-jet to clear, then camera-inspect for cracks or offsets.
• Cracks, severe corrosion, or collapsed sections: trenchless lining or pipe bursting; excavate only when required.
• Repeated backups from a belly/sag: targeted repair or replacement of the dipped section after locating it with video.

If you have an active backup, stop using water and avoid chemical drain cleaners until a technician inspects the line. <br/> Updated: 2026-05-07 <br/> Need help in Centennial, CO? Call (720) 740-0350 or book online.