layout for toilet/floor-drain/sink & sizing vent

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Eliot, Dec 16, 2009.

  1. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    Great site Terry.
    I installed a new 6" sewer 12" below top of slab where the old sewer was 24" above. Now I want to put a floor drain in and I would like this to work well and never give me any grief.
    The restroom is 4 feet below grade and does get some flooding when it rains more then 2" an hour, so the floor drain is to be 3"
    I would like to tie into a 2" vent stack 15' horizontal and 45' vertical. This vent stack services a bathtub/sink two floors up.
    I forgot to draw the clean-outs, but they're there.
    Any layout advice is greatly appreciated, and please tell me I don't need to change my vent.

    Attached Files:

  2. Lightwave

    Lightwave New Member

    Messages:
    98
    Location:
    Vancouver, BC
    Using a floor drain to "fix" a flooding basement is like using a band aid to treat a gunshot wound.

    You need to get the water ingress problem fixed before it causes damage that a floor drain can't fix: damage like foundation subsidence leading to collapse of the building.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    drain

    Two questions come to mind.
    1. What's with the toilet up on a throne?
    2. WHO uses a 6" sewer pipe for a residence? That is usually reserved for large factories and HUGE condominium projects, (and even then it is not for the individual units). The BWV should be ahead of the toilet AND floor drain, assuming it works when it is supposed to. The old sewer being 24" above the floor should have been keeping the basement FROM flooding. Your "improvement" ruined that.
  4. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    6" SDR35 and other things

    The 6" SDR35 is what the city upgraded to I had to place the clean-out inside on this leg of the sewer as per city engineers advice, so I reduced to 4" after that. Even stranger--I had to install 2 2" conduits one for phone, one for cable.
    In this picture you can see a bit of lower leg of the 6" SDR, in the gravel, to the right of the main building drain sewer, and directly below the 3" gray electric conduit. This outside work is what has caused me to alter my toilet on a throne and install a floor drain. Also about the floor drain the flooding only happens when the wind is from the east and it rains 2" an hour. It flows across the sidewalk and overwhelms the drain to a gravel-bottom-cistern (built 1901) at the bottom of the wheelchair ramp. I can not change that drain, for it is below the cities storm sewer. I can put a floor drain inside though, for the once a decade event.
    The height of the sewer off the floor has nothing to do with the flooding, all the water comes in through the front door. It's that 1 in 3650 day (10 years) event that's a problem.
    In this picture (which has nothing to do with my question) I had to place: two 2" communications, one 3" sched 80 electric, two 6" SDR35 sewer, 3/4" copper water (wish I had put a sleeve for future water upgrade as I'm zoned business), gas (I didn't install the gas) and nothing could be within 12" of the electric.
    Back to the layout question, Do I really need a BWV on the toilet as the only fixture above it is the sink. This bathroom is the ONLY thing that drains to this sewer and is within 5' of the 6" sewer and I'm the first building at the top end of the city sewer. The old sewer had less of a drop to main and was very corroded 4" cast. It never had reversed flow, but if that is code I will install.
    In the drawing I have a vent about 5' from the toilet is that OK?

    Attached Files:

    Last edited: Dec 16, 2009
  5. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    The dry vent isn't allowed in most codes that I know of, can you wet vent in KY? If so, just run a 2" vent off of the lav and kill the other vent.
  6. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    The old unit (not me)

    The old toilet had a cast iron wye with a dry vent built in about one foot from the leaden ell–the flange sits on–so I... assumed...
    This toilet was added in about 1940 and I'm sure plumbing practices have changed. As long as it's to code and is is designed the best way.

    Another note to the flooding I did install a gravel pit to catch some of the rainwater. In the photo the top 3 steps drain some water into the pit and the first 3 feet of the wheelchair ramp drains to the pit which I put about 1-1/2 yard of gravel in it, but in Kentucky we've been known to get 6" of rain in 6 hours. Driven by the wind puts about 2500 gallons @ 3" deep in this unit.

    Again I'm off topic, is my layout of the toilet on a long 4" wye, followed by a long 3" wye for the sink and floor drain ok (left side of drawing)?
    and do I really need a BWV on the toilet?
    Get rid of the 2" vent on the left and put a clean-out there?
    Is 2" legal--it runs 15' horizontal to a 45' to the roof?

    I will be hiring a master plumber to upgrade my galvanized to copper next year, but the city has sprung this on my at a time when cash is low, so to reduce cost I would like to do some of the work. I do NOT want anything done half-assed. I worked in construction long enough to know when to ask questions.
    Thank you all for sharing your knowledge.
  7. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    The old unit (not me)

    The old toilet had a cast iron wye with a dry vent built in about one foot from the leaden ell–the flange sits on–so I... assumed...
    This toilet was added in about 1940 and I'm sure plumbing practices have changed. As long as it's to code and is is designed the best way.

    Another note to the flooding I did install a gravel pit (under the for rent) to catch some of the rainwater. In the photo the top 3 steps drain some water into the pit and the first 3 feet of the wheelchair ramp drains to the pit which I put about 1-1/2 yard of gravel in it, but in Kentucky we've been known to get 6" of rain in 6 hours. Driven by the wind puts about 2500 gallons @ 3" deep in this unit.

    Again I'm off topic, is my layout of the toilet on a long 4" wye, followed by a long 3" wye for the sink and floor drain ok (left side of drawing)?
    and do I really need a BWV on the toilet?
    Get rid of the 2" vent on the left and put a clean-out there?
    Is 2" legal--it runs 15' horizontal to a 45' to the roof?

    I will be hiring a master plumber to upgrade my galvanized to copper next year, but the city has sprung this on my at a time when cash is low, so to reduce cost I would like to do some of the work. I do NOT want anything done half-assed. I worked in construction long enough to know when to ask questions.
    Thank you all for sharing your knowledge.

    Attached Files:

  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    drain

    quote; It's that 1 in 3650 day (10 years) event that's a problem.

    You forgot that 2 or 3 of those years will be leap years, so it would be 3652 or 3653 days. Those extra days may be when it happens a second time in ten years. As long as the toilet is that high, there is little possibility of it overflowing from a sewer flood. And if the flood water is coming in through the door, and not from the sewer, you do not need a BWV on it either.
  9. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    I'm confident that the sewer won't flood, as the city upsized the old 1850's clay, buried it deeper, I'm at the high point on the system, I'm the first building on the system, It rarely rains on the leap day, the 4" clay sewer laterals are now 6" plastic and deeper, it never flooded before.
    Now how do I install a BWV on the front door?
    Are those long-combo-tee/wye ok to put on their sides?
  10. dlh

    dlh plumbing consultant

    Messages:
    10
    Location:
    dallas texas
    most areas today do not allow storm water to be drained into the sanitary system especially if there is a seperate storm system, which one of your pics leads me to believe your area has, and if so then you need to run another line for the floor drain since it will essentially be storm water not waste from such things as mopping and the toilet overflowing.

    i would install a trench drain in front of the door to keep the water out of the building completely if i were you

    those are combos but they are not tee-wyes they are wyes and 1/8th (45*) bends hence the name combination and they are perfectly fine on there sides where a tee-wye (sanitary tee) is not
  11. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    The only question I have is do they allow SDR 35 inside a building under your code?
  12. Eliot

    Eliot New Member

    Messages:
    7
    Location:
    kentucky
    SDR35 inside

    Quote: "I can not change that (outside) drain, for it is below the cities storm sewer. I can put a floor drain inside though, for the once a decade event." The cities sanitary sewer is now very deep (they spent weeks breaking bedrock for it), so a restroom floor drain it is.
    It's really for overflows and mopping, uh huh, really.

    As for the SDR35 inside there was no choice as it needs a clean-out and there was no space outside for a clean-out. City engineers OKed it. 6" is too big and it may be a problem if I put a low-flow toilet on this line. 1.6 g may not be enough water to push the solids the 15' to where the wye in the sidewalk that rest of the building drains to.
    The city required SDR35 and clean-out to within 12" of face of building and I have electric conduit passing over that area, so the clean-out is inside.
    Today they installed the curb drain and they put it in front of my building and are increasing the slope of my sidewalk, so flooding is not that much of an issue - a working toilet is.

    Attached Files:

    Last edited: Dec 17, 2009
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