There are 3 Common Causes of Home Sewer Backups: A Clog. Just like your drain pipes, your main sewer line can become clogged, which can cause sewage backups in your home. Tree Roots. Another common cause of home sewer backups is tree roots. Broken or Collapsed Sewer Lines. A sewage backup on your property creates unpleasant odors of course, but also several unhealthy living conditions that could place your family in danger. Raw or untreated sewage contains a huge variety of p