Double Sanitary Tee or Double Wye?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by MG, Oct 25, 2007.

  1. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    Last night I was having trouble figuring out how I will fit in all the fittings necessary for the CI removal project I have. Part of the problem is near the same point in the run I need to get a toilet and sump pump drain fitting in. Today the brainstorm arrived and its in the form of either a double sanitary tee or wye (vertically oriented).

    I've read that if the fixtures are far enough apart the tee is ok - they would be at least 18 inches from the branches of the fitting - can I go w/either one depending on how it fits in? I don't have a ton of room to work with.

    Either way it bites butt...those are expensive fittings but I think it might be the ideal solution to my problem if they'll fit.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,835
    Location:
    Cave Creek, Arizona
    fitting

    WE would have to see the location or a drawing of what you want to do. A third option might be a 3" sanitary tee with a 2", left or right, side inlet for the pump discharge. That would eliminate the two connections opposing each other with the attendant problems that causes.
  3. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    Going to 3" isn't an option - there are two sinks on the floor above that drain into the 4" stack which drains into the run I'm working on.

    I'll have to try to take a picture of it - the problem is the combo fitting that I'll be using to replace the 4" CI sanitary tee. That combo is huge compared to the tee and pushes everything back and up compared to the old stuff.

    Ideally it would be a lot easier with a wye and 1/8 and then a 4" 90 degree elbow with a 2" side inlet - but I have never seen one.

    This is a rough idea of what I am thinking about - mainly because the ST fitting has a shorter footprint than a double wye.

    Attached Files:

  4. patrick88

    patrick88 Plumber

    Messages:
    836
    Location:
    Webster Ma.
    I would not tie in a sump pump. Connecting a sump pump to a main drain might not be in your local code. I would have the sump pump drain out your sill and away from your house. That might answer some of your drain questions.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,835
    Location:
    Cave Creek, Arizona
    fitting

    You cannot legally use that fitting, and if there is plumbing on the floor above it using the pipe as a drain, you cannot legally tie the toilet into it, unless you provide it with its own vent.
  6. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    I got the solution figured out tonight and it won't involve a double wye or double sanitary tee. Tough to explain without a lot of pictures.

    As for the sump pit going into there - it has been configured that way for 20+ years and wasn't an issue when we bought the house. I'm just replacing what is already there. Its an unusual setup.
  7. patrick88

    patrick88 Plumber

    Messages:
    836
    Location:
    Webster Ma.
    Still doesn't make it right.

    So when your house sewer main backs up and your sump pump starts to run it will be lots of fun for all involved.:eek:

    My favorite story is the guy that had that set up and called because his 1st floor bath tub was filling up with sewer water.:eek: Said the same words as you.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,835
    Location:
    Cave Creek, Arizona
    solution

    I got the solution figured out tonight and it won't involve a double wye or double sanitary tee. Tough to explain without a lot of pictures.

    Your original drawing shows a very simple possible setup, so any solution should be "easy" to explain with very few pictures.
  9. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    The solution will be that the toilet will go into a regular wye. The fitting for the pump will be back up the line a bit further.

    If I could find a local plumbing supply house that carries a 4" sanitary tee with a 2" right side inlet it would be a more efficient setup - I will check today w/the place I bought my riser clamps awhile back.

    The unusual setup:

    1. Split foyer house - all fixtures except the washing machine are on the top floor. Two toilets empty into the horizontal, along with the tub and a sink from the small bathroom. It is a form of a wet vent I believe. The laundry room is next to the garage.

    2. The sewer main is in the garage - but not into the floor. It is about 4' off the ground. It runs out behind the house and then down a small incline to the main line. It would take one hell of a backup to get back up that thing.

    3. The laundry room is next to the garage - and has two sump pits in it tied together w/a pipe under the foundation. One looks like it was to empty ground water out into the yard somewhere - but it hasn't been connected in years and was disconnected long before we bought the house. The other is setup for the washing machine to drain into - this is the one that has the sump pump tied into the main line. The only reason I can see for having the pit empty into the line instead of the yard is that every weekend you do laundry you'd have a big wet mess somewhere out there. I would not be surprised at all if this is not allowable, but there is no room upstairs for a laundry room. This house was built in 1971 and there are at least two more on the block designed similar. However, their mains are into the floor.

    So...this is the story. We don't plan on moving any time soon, but the leaky cast iron at ceiling level in the garage has to go one way or another. I'll probably have code violations somewhere in the mix - but I'll do my best so things work.

    Here is an image of the current configuration - this is how it was when we moved in. Its worked fine but the CI is leaking because it has peeled up in one section.

    Attached Files:

  10. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    One last followup - I found a 4" ST w/2" RSI! Woohoo!
  11. patrick88

    patrick88 Plumber

    Messages:
    836
    Location:
    Webster Ma.

    Well I have seen houses with a 100' main drain going down a steep hill back up. Back ups are caused from many things and most of the time it is caused from old age. Your pipes are leaking in your garage well just think of the one under ground that you can't see.

    I would try to just upgrade things as close to apples for apples so you don't run into to many problems.

    Well that changes things. That is not a sump pump or atleast the one that is for the laundry. I never would have said the other stuff. I was just thinking of saving you alot of future trouble. I will advise that you try and upgrade things as close to your local code as you can.
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