The following are signs that tree roots may have invaded your sewer line: Slow draining sinks, tubs, etc. Tree roots can enter the exposed sewer lines via cracks or other openings against exposure to rainfall. A clog can occur slowly over time until you eventually notice it affecting your sink or other drainage system. Sewer odors Tree roots are excellent at absorbing wastewater that comes into contact with them. As they grow inside the sewer line, tree roots can absorb a significant amount of water. If they are near your home or office's sewage pipe, you will notice a sewer odor coming from your sinks and drains even when you use chemicals such as anti-clog agents to prevent tree root clogging in your sewer lines. Toilet backup Tree roots growing in the sewer line can cause tree root damage to private property including tree root blocking of drain systems that may include tree root damage to toilets which can trigger tree root backups and related problems such as tree root rot and mold. Foundation issues Tree root damage to foundations is another problem caused by tree roots if there is too much pressure on the foundation walls themselves. This causes cracks in the foundation walls that can lead tree roots to enter the interior of the home, office building or related structure. Unnatural formation of yard growth Tree roots will grow into any opening in your sewer line including cracks which can be discovered using a sewer camera inspection. Lawns and other vegetation near houses with tree root problems may appear to wilt during dry seasons, but flourish when it rains heavily due to tree root interception of water inside the sewer line.