Old drain is at least 45 years old and has broken under a concrete slab and
roots get in and clog it up every 6 months. One estimate was for $3K,
which includes breaking a concrete patio, installing new drain pipe and
replacing patio.

There are 2 alternates that I thought about doing instead to keep from
breaking up the concrete....

1 - Slide a PVC pipe inside the old terra cotta pipe. Advantage is lower
cost, but it also makes the pipe diameter smaller.

2 - Re-route a new drain pipe around the patio. This would be my first
choice except that the only way is to go out 90 degrees from the original,
which means either two 90 degrees bends -- or 45 degrees if that is
available.

I posted a sketch the following newsgroup - the closest one I could find to
plumbing...

alt.binaries.pictures.woodworking



If anyone has experience with this kind of situation, I would appreciate
hearing a few words.



Thanks!



Bob