New shower venting question

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by jwbr, Nov 28, 2010.

  1. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    I'm doing a remodel on my bathroom and adding a shower where a bath once was. I'm trying to figure out the best way to vent this. In this drawing I show 3 options.
    [​IMG]
    -A would be to vent down from the shower trap about 5 feet to an existing vent. Is 5' of sharing a water drain too much length to then vent?
    -B would be to tie into the drain that is currently used by another shower and "share" its vent. I have doubts about this because of whether the current vent would be effective since it is "up" from the draining angle of the drain. And I'm not sure two units could share a vent like this even thought they are not used at the same time. I don't have it on the drawing but the sink down form the current shower is vented straight up to the wet vent.
    -C would be to move the previous drain a little ways and vent as shown to a current wet vent. The vent is just a couple of feet away.

    I have real limitations with the structure of this house and how much I can change things. Any feedback would be great.
    Last edited: Nov 28, 2010
  2. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    I don't think I can comment, your drawing doesn't have any perspective, sorry.
  3. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    It's a view from above if that helps.
  4. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,239
    Location:
    Land of Cheese
    To be sure we would need to see an accurate isometric diagram of your system

    The code I am familiar with (WI) allows a a 2 inch drain at 1/4" inch per foot pitch to have the vent up to 6 feet from the trap weir.
    It should be noted that tub drain lines are normally 1.5 inch and will not meet code for a shower.
    Vents must be vertical until they are at least 6" above the flood rim of the highest fixture served by by that stack.
  5. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    OK, See if this works. Once again my questions are which possible vent (in blue) works better than the other and if it would be possible to drain to the existing drain (orange dotted line) and essentially "share" the vents that are already there (long shot but had to ask).
    The possible vent on the right is a significantly shorter distance from the drain than the one on the left.
    [​IMG]
  6. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,239
    Location:
    Land of Cheese
    The vent must rise vertically, downstream of the trap and before it ties into the existing drain. The one on the left would work assuming you make the proper connections within the distance and pitch permitted by your code.

    Some areas allow a shower to be wet vented through the lavatory. Here that would require the lav drain/wet vent to be 2"
    You have not drawn that properly, if that was your intention (on the right).
  7. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    Sorry if my drawing is off. Basically on the right (in blue) I would vent after the trap then tie into the existing vent (red). The red vent is 2" currently.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,304
    Location:
    Cave Creek, Arizona
    You show two NEW shower drains and two NEW shower vents. The "right" vent is horizontal, so it is not correct, but the "left" one appears to be too far from the trap to be correct also.
  9. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    There is only one NEW shower, the other one shown is an existing one. I changed the drawing, the right vent would be angled, and not completely horizontal.
    Would it even be possible to drain to the other current drain (in purple) and "share" the current vents now used by the existing shower and sink? The shower drain would angle down to that line.

    [​IMG]
  10. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Fixed.... As long as wet venting is allowed under your code.
    Your drawing doesn't show traps but I'm assuming they exist between the fixture and the vent.

    PlumbingVents3.jpg
  11. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    The existing shower is staying in place.
    So am I reading this right that you're saying if I tie into the sink drain (orange) that I don't need a separate vent (blue in the other drawing) for the new shower? The new shower drain will be about 3.5 feet from the sink drain.
    Yes, traps will of course be used!
    Last edited: Nov 30, 2010
  12. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Yes as long as wet venting is allowed by your code.
  13. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    Wet venting is permitted. But if I'm reading the code correctly, it says:

    •Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vented.

    But it also says:

    •Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 906.1.

    Which for 1.25 is 5' and 2" is 8'

    Reading the code, would connecting to the sink line be considered permittable?
  14. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Can you place dimensions on the drawing?
  15. jwbr

    jwbr New Member

    Messages:
    18
    Location:
    Central Ohio
    I figure you want dimensions of the shower/drain/vent area?
    Here's another drawing, if you need any other dimensions, please let me know.
    And thanks a lot for looking this over!
    [​IMG]
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