: Terry,

: I'm plumbing in a new master bath and had a couple of questions. I'm runnng 1/2" copper lines across a room (8ft) and I want to avoid drilling through the joices and having several copper joints, so I was going to notch the joices. But could I just secure the copper lines on top of the joices and then put the subfloor in (the subfloor is 3/4" Ply with 1/2" concrete board)?

: Second question. I know there are critical distances to consider between traps and vent lines. I want to run a vent connection horizontally across the same room from a sink to the main vent stack are there any critical distances I have to observe for this case?

Rob,
Do not notch the floor joists. To maintain building code, there is supposed to be 2" of wood on the bottom and the top of the floor joist. Holes are to be in the middle portion of the joist.

1.5 trap arms can be 42" from the vent
2.0" trap arms can be 60" from the vent.
A vent can be run horizontal in the room.
Most inspectors allow 1/3 the horizontal to the vertical without increasing one pipe size.