AAV vent & trap in wall

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Alpac, Mar 29, 2008.

  1. Alpac

    Alpac New Member

    Messages:
    7
    My 30-year-old Laundry room (LR) has a WM drain with no trap or vent. So, I am remodeling trying to place a new drain, trap and vent.

    I just started and found the wall cavity is on 12 inch centers. Hardly room to place a 2 inch trap. Its an external wall so I am not inclined to file permit to modify studs. Or is this my only option?

    I am permitted in Redmond, WA to add a AAV and new drain. How? IF I am able to get a line in, no trap will fit.

    Am I forced to put a trap outside the wall?

    Is putting a trap on a horz section below the floor in the crawl space with AAV vent a bad idea?
  2. Terry

    Terry Administrator Staff Member

    Messages:
    14,943
    Location:
    Bothell, Washington
    The trap needs to be above the floor.
    The AAV can be in the open. It can't be in a closed off wall.
    How did a p-trap not be included in Redmond?

    Since you have some room behind the washer, I don't think it would be a problem if its not in the wall.

    You do want the trap and the vent (AAV)
  3. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,714
    Location:
    Central Florida
    If you can, post a picture of the situation.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    drain

    This is something we do daily, and do not consider it an insurmountable problem. Put the tee in one cavity and the trap in the next one with a hole in the intervening stud for the pipe to go through.
  5. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Depending on the climate you may not want a trap in an exterior wall. You may find the line clogged by a frozen trap.
  6. Terry

    Terry Administrator Staff Member

    Messages:
    14,943
    Location:
    Bothell, Washington
    In Redmond Washington, it doesn't get that cold.
    It's too close to Puget Sound, Lake Washington and Lake Sammamish.

    hj is right, we can just drill into the next stud bay.

    It snowed here last night, but it takes several days of below freezing here to do much.
    We do have to have frost free hose faucets, and the water services need to have 24" of cover.
    Local code calls for insulating pipes in the crawlspace, even though they don't freeze there. (Not unless they are right in front of a foundation vent)
    Any water lines in the attic will freeze, insulated or not, unless they are near the warm ceiling and batts of insulation are over them.
    Last edited: Mar 30, 2008
  7. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Thats why I said depending... I know it could be either way in Washington state so I let the locals decide.

    The 2 piece Ox-Box might be ideal for your application. http://www.siouxchief.com/oxbox/
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