Basment Toilet - New Construction

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by MaximAvs, Aug 8, 2007.

  1. MaximAvs

    MaximAvs New Member

    Messages:
    23
    SO I'm installing a bathroom in my basement and I'm at the portion of installing the toilet. We have a slab basement floor, and the builder (1980s) left about 9" of 3†ABS pipe sticking out of the concrete where the toilet should go. My question is on the flange. Please tell me if I’m wrong on any of the following, and suggest any steps I am missing.
    I was going to cut the pipe off flush with the floor, and then get a plastic flange with a molded piece of female pipe in the center to be “glued†inside the pipe in the floor. My only concern with this is that these flanges have a lip on the bottom in the middle that will not allow the flange to sit flat on the floor. It’s up about 1/8†– 3/16†high. The other issue is if the flange cranks over time, There would be no way of replacing it without breaking up the concrete.

    [​IMG]

    What sort of flange do I need and how does the one you suggest create a good seal AND be repairable and all this without having to bust up concrete? Thanks for any suggestions you have!!

    Sean
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Location:
    New England
    Check carefully around the base of the pipe; if you are lucky, the builder put a sleeve around the pipe you can dig out to allow you to put a normal flange on the outside of the pipe. Note, it might be covered just at the top by a thin layer of cement.

    It is considered 'ok' to use an internal flange on a 4" pipe (although outside is better), most do not like to do it on a 3" pipe.

    The flange needs to sit flat on the floor, with no space underneath and you need to anchor the rim to the concrete, otherwise an inadvertent knock on the toilet after installation could break the flange. Plus, if it sits higher than that, some toilets won't fit - they'll be held up by the flange, rock, and break the wax seal in addition to the flange.

    You might be able to use an internal cutter to get the top of the pipe slightly below the surface to then allow the flange to set down flush with the floor.
  3. MaximAvs

    MaximAvs New Member

    Messages:
    23
    There is what looks like tar paper wrapped around the pipe now, but there would be no way that there would be enough space between it and the pipe to get an "outside" fitting.

    On another note, should I be looking at a metal flange with an ABS fitting?!

    Thanks for the help

    Sean
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,017
    Location:
    New England
    Regardless of the materials of the flange, the ring must be anchored to the floor. There are numerous brands, each with slightly different construction details - one may allow it to fit in there flush with the floor. Again, an interior flange on a 3" pipe is to be discouraged.

    Normally, there will be some covering on the floor - the flange should sit on top of the finished floor, not just the subfloor (or in this case the slab). So, if you were going to put down tile, you'd be raising the height enough to make room for the bevel on the flange. Vinal probably wouldn't be high enough, though.
  5. markts30

    markts30 Commercial Plumber

    Messages:
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    Location:
    Phoenix, AZ
    For information sake for the other pros on the board....
    This may not help you much as there is some cost involved - how much you could call around and find out - might not be too much...
    I ran into a similar situation whil helping a buddy redo some plumbing and just core drilled a 5" hole around the pipe...
    Chipping the "sleeve out was easy and took about 5 min...
    Outside flange fit like a glove...
    If you are going to do this, remember to plug the pipe with a test ball or rubber plug so the water for the core driller does not just run down the drain and make the diamond bit cut dry....
  6. MaximAvs

    MaximAvs New Member

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    23
    jadnashua...

    Yes, I have already laid a vinyl sticky tile flooring down on the floor.

    markts30...

    I like your idea, but I'm not sure I want to do that with the room almost done.

    I'd sure like a flange that had a metal ring and an ABS middle to bond to the inside of a 3" pipe. If that's not available I might be chipping concrete.
  7. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    Licensed Grump
    Coring...I'd just get (rent) a rotary hammer with a flat bit...chisle the outside diameter and like Markst said..make ABSOLUTLEY sure you cover the drain....coring machines are messy, cumbersome.
    I also probably prefer it because I keep a rotary on my truck.
  8. MaximAvs

    MaximAvs New Member

    Messages:
    23
    So, the censensis is to chisel out the concrete around the drain?! Also an inside mount on a 3" drain is frowned upon?!

    Thanks guys!

    Sean
  9. MaximAvs

    MaximAvs New Member

    Messages:
    23
    Here's picture of the situation. I'm pretty sure you've seen this, but I thought I'd post a picture anyway.

    [​IMG]


    Sean
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,641
    Location:
    Cave Creek, Arizona
    pipe

    As soon as you said, "3 inch pipe", "encased in concrete", "insert flange", "ridge", you pretty much negated any hope of it ever being "easily repaired in the future".
  11. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    Location:
    Licensed Grump
    Seeing the pic I can honestly say I wouldn't even consider coring it wet...they do have dry bits though, but I stand by my original rotary hammer suggestion.
    Also..Hard wood flooring isn't the greatest idea under a toilet.
    It'll swell when wet and push the toilet up off the flange, slowly breaking the seal...can't be too good in the longterm on it's appearance either.
    Even if you are able to get er'yone to "use their aim", bowls tend to sweat in warm or humid conditions.
  12. MaximAvs

    MaximAvs New Member

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    23
    Actually it's not real hard wood! It's a vinyl floor that looks like hard wood! It comes in 4"x36" strips that you lay like a wood floor, but just stick to the concrete/subfloor. It carries through my basement into the lounge.
  13. MaximAvs

    MaximAvs New Member

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    23
    It's really looking that way!! Nothing has been easy with this project. I was really hoping that one thing would be easy.

    Sean
  14. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    well what'll they think of next?!?
    At a glance it looks real...whats the stuff called?


    (600th post!...soon I'll be at "Senile member" status!)
  15. MaximAvs

    MaximAvs New Member

    Messages:
    23
    I forget the name of it off the top of my head (I'm at work), but I will take a picture of the box when I get home. I know I picked it up from Lowes over in the sticky vinyl tile area.
  16. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,347
    Location:
    Cincinnati OH
    I have an idea cultured marble slab .We used to put them under w/c on wood floors as per code.This will give 1/2 inch more to play with.So you do not
    have chip out so much concrete.Also you will have room the under side of the flange.
    Last edited: Aug 11, 2007
  17. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    By the way..welcome to the forum cwh..I'll guess you're a plumber by trade.
  18. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
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    Location:
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    posts

    600 posts? That means you are still a preteen, not a senile senior citizen.
  19. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,347
    Location:
    Cincinnati OH
    Yes Grumpy I am and thank you.We will talk again.
  20. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    Sure...now convince the "better" half.
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