4 inch vent pipe in a 2x6 stud wall?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Antonio4791, Jul 31, 2010.

  1. Antonio4791

    Antonio4791 New Member

    Messages:
    11
    Location:
    South Pasadena CA
    Hi all, I just built a 2x6 stud wall for my new bathroom. I would like to put in a 4 inch vent pipe but I'm wondering if 4 inches is too wide. Obviously there are code issues with boring studs, but what about top and bottom plates? This is a load bearing, double top plate wall. A 2x6 is only 5.5 inches wide and the OD for "4" inch DWV pipe is 4.5 inches, leaving only a half inch on each side of the plates. That seems too big to me. I suppose I can get by with 3 inch. I would like to do to the toilet drain with 4 inch and would like to have the vent be the same size. Is it OK to have toilet drain by 4 inch and the vent be 3 inch?
  2. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    Depending on the load of your system, you could vent a toilet with a 2in line, unless you have an extreme load on your whole system 3in should be fine.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,293
    Location:
    Cave Creek, Arizona
    Plates only support things where they cross. We drill 4" pipes through 6" walls all the time, otherwise there would be no way for us to install our piping.
  4. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Double up the studs on either side of the pipe and plate it when you are done.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,293
    Location:
    Cave Creek, Arizona
    NEVER have had to reinforce the wall after installing a vertical 4" stack. Just as I have never had to do it with a 2" pipe in a 4" wall, which would have the same problem, if it were a problem in the first place.
  6. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    IPC wants simpson ties top and bottom on exterior or load bearing walls because......... If there is a fire in the house that portion of the wall can be weakened bu the fire and when the fire department puts the water to the exterior it can blow the wall in and crush or trap fire fighters that may be inside. I know it's a long shot but apparently it has happened more than once.
  7. 3m

    3m New Member

    Messages:
    76
    Location:
    NY
    I failed an inspection for the very same reason, when I questioned the inspector on this He stated I know you guys have been doing it this way for ever but now they require a 16 inch long plate with 8 16 penny nails on each side. This is to keep the top plates from pulling apart, if the house has exterior plywood installed the plate is not needed
Similar Threads: inch vent
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & can vent go down few inch? Dec 18, 2012
Plumbing Forum, Professional & DIY Advice, Tips & effect of raising floor 12 inches on toilet vent Mar 15, 2010
Plumbing Forum, Professional & DIY Advice, Tips & Shower - 2 inch transiiton to 1 1/2 inch and venting Jun 20, 2009
Plumbing Forum, Professional & DIY Advice, Tips & 2inch packer pvc drop pipe stuck in well if it breaks what can i do Jun 2, 2014
Plumbing Forum, Professional & DIY Advice, Tips & 4 Inch Toilet Flange Spigot Pipe May 20, 2014

Share This Page