A mainline is the sewer line (or main sewage pipe) between your house and the street. All sewage/waste from your home gets eliminated through this line.
For example, after waste is placed into a toilet, it is flushed. The waste is then pushed through the mainline into the public sewer system.
Some examples of what clogs a mainline include:
- Toilet paper, baby wipes, napkins
- Broken or collapsed sewer lines
- Tree roots
Typically, a backup will occur at the line’s lowest point, such as a basement floor drain or basement bathroom. These out-of-sight fixtures are why most backups aren’t usually noticed until it’s too late.
By the time you do see the problem, it’s because the basement has already begun flooding. More so, a potentially lasting problem, the real threat of mold extends to your property and possessions. These need to be remediated. The immediate attention of a plumber is required to stop the damage as quickly as possible. In a drain backup situation, everything affected by the sewage (walls, furniture, etc.) will need to be removed and sanitized, and materials replaced. For more information, read: “3 Common Causes of Drain Backups.”