Roots growing through cracks or defective joints sometimes clog outside
drains or sewers. You can clear the stoppage temporarily by using a
root-cutting tool. However, to prevent future trouble, you should
re-lay the defective portion of the line, using sound pipe and making
sure that all joints are watertight.[2]
[Footnote 2: For information on laying sewers, see Agriculture
Information Bulletin 274, "Farmstead Sewage and Refuse Disposal."
For a free copy, send a post card to the Office of Information, U.S.
Department of Agriculture, Washington, D.C. 20250. Include your ZIP
Code in your return address.]
If possible, sewer lines should be laid out of the reach of roots. But
if this is impossible or impracticable, consider using impregnated
fiber pipe which tends to repel roots.