Bathroom plumbing layout

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by bmwpowere36m3, Jun 5, 2014.

  1. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    I'm remodeling my house (single-story ranch) and now fixtures are much further away from the original main stack. The main stack is on the backside of the house, the sewer line comes up the side and around the back of the house.

    I want to avoid running 3" waste lines horizontally down the side of the foundation walls in the basement since they would cross my basement windows. Instead I was planning on adding another stack near the master bath, cutting thru the foundation and teeing into the sewer line.

    plumbing_design0.jpg

    To the Original stack I plan on connecting the kitchen sink/dishwasher, washing machine (basement) and double vanity (from master bath). To the Proposed 2nd stack I plan on connecting the shower, tub and toilet. The reason for running the double vanity line to the original stack is that I want to keep it up in the floor joists, but I could also run it to the proposed 2nd stack.

    For the master bath, the plan is to have a 3" waste stack and 3" vent thru roof. To the 3" waste stack would connect the toilet drain and a 2" horizontal drain line serving the tub and shower.

    plumbing_design1.jpg

    Toilet drain: flange (3")>long 90>straight>long 90>wye fitting on main stack

    Shower drain: flange (2")>p-trap>wye>2" horizontal drain... a few feet down the horizontal drain line a sanitee (on its back) to serve as 1.5" vent>3" main stack vent

    Tub drain: drain assembly(1.5")>p-trap>straight>45 elbow>wye>2" horizontal drain... a few feet down the horizontal drain line a sanitee (on its back) to serve as 1.5" vent>3" main stack vent

    Horizontal drain line: wye on end w/ cleanout and tied to main stack via sanitee (3x3x2)

    plumbing_design2.jpg

    Thoughts? Is it kosher?
  2. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    Based on what I've read I think it doable... the horizontal drain (2") becomes the trap arm between the p-trap and vent. So as long as I locate the vent (flat vent, sanitee, 1.5") within 5 ft of the shower and another one within 3.5' of the tub (both vents downstream of their p-traps). Horizonstal drain line is pitched at 1/4" per ft.

    I've decided to also tie in the double vanity drain line into the proposed stack, like this:

    plumbing_design3.jpg
  3. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Ok, I'll reply. First off, flat venting is illegal except in Massachusetts and using a sanitary tee in the horizontal position to receive waste is illegal in every state. Its impossible to give you solid and accurate advise based on the information provided. Every home is different. Framing and structural issues never seem to align with the plan you have in your head.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,515
    Location:
    Cave Creek, Arizona
    The "middle" vent has absolutely no function so it it basically cosmetic. How you actually install the piping will determine whether it is proper or not.
  5. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    I thought the middle vent would serve the tub p-trap since it's 1.5" and the main stack is over 3.5' away...
  6. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    I might have miss-worded "flat-vent" as the vent pipe (1.5") will rise straight up off the horizontal drain pipe (2") and not at an angle or horizontally. I thought a sanitee on its back for a vertical vent connection to a horizontal pipe was okay?
  7. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    Basically like this image:

    flatvent5.jpg

    H is my 3" main stack, D is the vent connection (going straight up, no horizontal section), F is either the tub or shower p-trap.
  8. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    used as a vent only, the San-Tee is ok in that position although it pisses off the drain cleaner guys that insist on rodding vents for no reason LOL
  9. bmwpowere36m3

    bmwpowere36m3 Member

    Messages:
    30
    Location:
    CT
    So in the picture above is that considered flat-venting?
Similar Threads: Bathroom plumbing
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & Plumbing Remodel & Bathroom Addition May 7, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Bathroom Plumbing? Feb 18, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Which diagram works for bathroom plumbing Feb 18, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Basement plumbing/bathroom Feb 17, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Plumbing new bathroom in my own addition need help please. Dec 9, 2013

Share This Page