In article ,
dustbird wrote:

Why don't plumbers use metal drainpipes of some sort? I assume roots
couldn't penetrate these. Is it just plastic pipes? Are metal pipes too
expensive, or would plumbers lose repeat business?


The problem is that the roots penetrate the joints, not the pipes
themselves. The pipes might be made of cast iron, plastic, clay, or even
cardboard (yes, there were sewer lines made of cardboard and tar). Cast
iron *is* the most expensive (and required for commercial buildings) but
it will have the same problems with tree roots as plastic does.


Dimitri