We never attempt to clear sewer mainlines from roofs. The Uniform Plumbing Code cites that cleanouts are required on all plumbing systems. Usually the cleanouts were installed originally and have been covered over by concrete, asphalt, landscaping, etc., or removed to accommodate patios, porches and room-additions. Taking sewer cleaning equipment on the roof is risky and dangerous. Damage to roofs (the equipment is heavy and awkward) is a concern, not to mention the worker’s-comp issues when a workman is injured. A 200 lb falling sewer machine is obviously a danger to customers and their family members, as well.
Additionally, most roof vents are maximum 2” in diameter. Mainlines are always 3”, or 4” in diameter, which means if you are able to “hook” an intruding root system in the mainline, you are likely to break your cable trying to bring it back through a 2” vent. That is why we always ask if you have a cleanout available. If not, we may be able to pull a toilet and clear the line, but the proper and most effective application is to locate the line and install a two-way cleanout outside the house (or business).