Mikebanks
May 20, 2012, 12:27 AM
Can I vent them  with just one 40mm vent
speedball1
May 20, 2012, 03:50 AM
Can I vent them  with just one 40mm vent
Hi  Mike    and Welcome to The Plumbing Page. At AskMeHelpDesk.com. 
Please explain , in detail. What "back to back "  "P" traps are.  If you're asking if you can vent two fixtures with one vent the answer's yes you can.  *If it's anything else click on back with more details.  Good luck,  Tom