How Roots Obstruct Pipes
Roots require oxygen to grow, they do not grow in pipes that are full of water or where high ground water conditions prevail. Roots thrive in the warm, moist nutrient rich atmosphere above the water surface inside sanitary sewers.
The flow of warm water inside the sanitary sewer service pipe causes water vapor to escape to the cold soil surrounding the pipe. Tree roots are attached to the water vapor leaving the pipe and they follow the vapor trail to the source of the moisture, which are usually cracks or loose joints in the sewer pipe.
Upon reaching the crack or pipe joint, tree routes will penetrate the opening to reach the nutrients and moisture inside the pipe. This phenomenon continues in winter even though trees appear to be dormant.
Once inside the pipe, roots will continue to grow and if not disturbed, they will completely fill the pipe with multiple hairlike root masses at each point of entry. The root mass inside the pipe becomes matted with grease, tissue paper, and other debris discharged from the residence or business.
Homeowners will notice the 1st signs of a slow flowing drainage system by hearing gurgling noises from toilet bowls and observing wet areas around floor drains when completing the laundry. A complete blockage will occur if no remedial action is taken to remove the roots/blockage.
As roots continue to grow, they expand and exert considerable pressure at the crack or joint where they entered the pipe. The force exerted by the root growth will break the pipe and may result in total collapse of the pipe. Severe root intrusion and pipes that are structurally damaged, will require replacement.
Tree Roots in Sewers
Tree roots growing inside sewer pipes are generally the most expensive sewer maintenance item experienced by City residents. Roots from trees growing on private property and on parkways throughout the City are responsible for many of the sanitary sewer service backups and damaged sewer pipes.
Homeowners should be aware of the location of their sewer service and refrain from planting certain types of trees and hedges near the sewer liners. The replacement cost of a sanitary sewer service line can be very costly.