If a tree is growing well, a survival mechanism is to explore the soil for supplies of oxygen, nutrients and water. It is our belief that tree roots do not cause sanitary line leaks. However, if a water vapor source or a water leak is available, the tree root will seek the water location as a survival reaction. There is doubt at this point, given an available water vapor source or a leak, that the tree root can make a minor problem significantly worse. When root blockage situations are suspected, the homeowner is strongly advised to regularly apply root inhibition products to sanitary lines, carefully following label instructions.