Shifting soil, or freezing ground can block, restrict, or collapse pipes and damage water and sewer lines. Interestingly, the number one cause of sewer line back-ups, cracked lines and drainage problems is caused by root infiltration. A pipe can easily be taken over by a trees hair like root mass and then quickly clogged with toilet paper, debris and grease coming from the home to the main sewer line. When theses roots grow, they will put the pipes under serious pressure and the pipes will eventually crack.