I have used some 2" ABS pipe underground ( under basement concrete floor ) in Ontario Canada, is that allowed

Hi Shane...

The simple answer is that 2" ABS and 2" PVC are allowed underground but only a local inspector can tell you which one they prefer in your area.

In my area they sell both ABS and PVC but most of the inspectors want PVC. You can imagine my surprise when I ran into the first inspector that wanted ABS in "his town"...*UGH*....luckily worked out OK with just an agreement to use ABS in "his town from now on"... ;)

Call a local plumbing inspector to confirm all is up to code, but ABS is certainly approved for underground use!

Mark