What size toilet flange and closet bend do I need?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Lakee911, Dec 9, 2012.

  1. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Hi All,

    I'm having trouble determing whether I need a 3" or a 4" closet bend and flange for this toilet. The low wall mount tank is marked KOHLER USA and both the tank and lid have Kohler part numbers marked K-6802. They were cast in early 1930. The bowl, which I assume was original along with the tank is marked 13/C (thirteen with a C below it) and was cast in late 1929. Most vintage toilets that I have seen online from this era are specified to have a 4" flange and closet bend. Some are even noted that a 4" x 3" closet bend will not work. I snapped an photo of the horn and it looks pretty small. What size should I use? (I have to cross a floor joist which makes 4" tough in a 2x10--steel would be involved--otherwise I'd just use a 4" drain and call it a day).

    [​IMG]

    I'm also not sure of the rough in. When I re-installed the original flush ell, I measured 14-5/8" from the back of the tank to the centerline of the horn. Can I just shorten it up by 3/4" or so and install it on a 14" rough in? I hate to plumb up a non-standard rough-in and have problems in the future if the toilet is changed.

    Thanks,
    Jason
    Last edited: Dec 9, 2012
  2. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,360
    Location:
    Yakima WA
    First of all, your closet bend has to match the drain pipe size, not the toilet. The flange has to match the closet bend. The top of the flange is the same size for all. Your toilet is a 14" rough-in. The fact that your flange measures an extra 5/8" just means the toilet will sit 5/8" further out into the room and have that much extra space behind the tank. Toilet come in standard rough-in sizes of 10", 12", and 14". Only a few models choices are available in 10" and 14" because 12" is the basic standard rough-in. Toto makes an adapter for a few of their models that permits these toilet to install and any of the 3 rough-in sizes, but these adapters only work on these specific models. My question to you is why in God's name are you installing an 85 year old toilet. This is most likely a 7 gallon per flush monster with obsolete repair parts. I note by the number of posts you have made that you have been around this forum for a long time and surely should know there are far better choices for toilets that are not expensive and will perform well on 1.28 or 1.6 gpf. If you were restoring a vintage automobile, I might understand why you needed vintage parts, but toilets are another matter. Maybe I'm missing something???
  3. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,249
    Location:
    Land of Cheese
    Dump the toilet and install your plumbing for a 12" rough-in. Every store in the country carries toilets for a 12" rough, and only a few carry anything else, and then you will pay plenty extra for it.
  4. Terry

    Terry Administrator Staff Member

    Messages:
    15,130
    Location:
    Bothell, Washington
    You can use a standard 4x3 closet flange and 3" pipe for that.

    Of course 4" is an option too. So, pretty much whatever you feel like working with.
    Most new toilets have about a 2" trapway, much like the bowl you have now. Though we also pull out some that look to be 1.5"
    Caroma is the only one I know of that has both a 3" trapway, the 305 bowl and one with 4" at the outlet, the 270 bowl.
  5. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Thanks for the replies!

    If I install it on a 14" rough, the tank is going to be sitting in the wall, not away from it, by 5/8". Seems more like it would be a 15" rough. If I can shorten up the flush ell (wall mount tank), I might try to get it into a 14". I understand that 14" is uncommon but 15" is virtually impossible. I don't want to completely screw the next person who comes along, if I can help it.

    I live in an old house, Gary. We're putting in a new bath and we're using almost all salvaged or period appropriate parts where we can. My sink is from 1928 if that makes you feel any better (or worse). :) In this case authenticity trumps efficiency. This toilet will not see a huge amount of use. Our half bath, which gets the majority of the use, is a 1.6gpf toilet and when the toilet in the other bathroom breaks it will be replaced by a Toto--I'm a big fan of Toto toilets.

    I understand where you're coming from. Actually there isn't too many parts on this sucker that are that uncommon. Douglas flush valve is common, fill valve is standard. The biggest thing is the flush ell and I think that if the original one lasted 80 years, the next one will likely last nearly the same.

    Well, I feel like working with 3" but what I'm concerned about is that so many toilets from this era are noited that they need to be 4". It would be a lot more work to go 4" here as I have to cross a joist and I'll likely be using some steel in that case. Maybe it will help to know why 3" became so popular...used to be all 4" right? Was 3" even an option in 1930?

    FYI, this is one of the locations that show most older toilets needing 4" ... http://deabath.com/Original/Or_Toilets/or_toilets.html

    Thanks everyone!
    Last edited: Dec 10, 2012
  6. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    I exchanged a couple of emails with John V. from Bathroom Machineries (http://www.deabath.com) and asked about the 3" vs 4" issue. He responded as follows:

    I'm going to go to blue box store tonight and compare flanges...sounds like a 3" flange is smaller than a 4" flange. I always thought a flange was a flange was a flange...apparently not.
  7. Terry

    Terry Administrator Staff Member

    Messages:
    15,130
    Location:
    Bothell, Washington
    I would take whatever flange you want to use, and push it onto the bottom of the bowl.
    That will be your defining answer.

    When I'm working with old Seattle homes from the 1920's, I use a 4x3 spigot closet bend with 4" hub flange.
    Mainly because I can make a tighter bend with it.

    That's not saying that a 4x3 flange won't fit your bowl though. It's pretty easy to pick up one and try it before any installing is done.

    Here's a lead bend replacement using 3" ABS
    [​IMG]
    Last edited: Dec 11, 2012
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,153
    Location:
    New England
    All toilet flanges are 4" at their inlet...some neck to a 3" pipe. There isn't a toilet made that requires a 4" pipe. Now, there are some places that sell 3" INTERNAL toilet flanges (i.e., it goes INSIDE of a 3" pipe) and those should be outlawed - they can create big problems. The ID of the horn on yours is about 2-1/2"...so a 3" pipe is bigger and should work just fine.

    There are lots of new toilets that look retro, will allow easy replacement should the next owner like it, and would fit on a standard 12" rough-in. While you have the chance, put in a new one at a standard rough-in.

    BTW, most inspectors would not approve installation of that beast...if it existed, you could repair it, but you usually are NOT allowed to install one in a new or remodel situation - that would require one to meet current water use requirements.
    Last edited: Dec 10, 2012
  9. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Ok. Well, that's good to know. Three inch pipe it is. I can better get the required slope with a 3" pipe. I know that the internal 3" flange is a bad idea...

    I know, I know ... I'm not listening *fingers in ears* lalalalaalala

    I'm going to try to shorten up the ell so I can get it on a 14" rough-in. I don't want to totally screw myself/someone later. Someday I'll come back and be asking why I didn't listen to ya'll, but I'll cross that bridge when I get there.

    (And by the way, I think that is rediculous....who does the government think pays for that water? I pay for that water! If I want to pay to waste it, I should be able to).

    Thanks fellas!
    Last edited by a moderator: Dec 10, 2012
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,153
    Location:
    New England
    Clean, potable water is not an infinite commodity - just ask those that live in the US desert southwest, or those in many other countries. Even where I live, they pull a lot of water out of the river, condition it, it gets used, cleaned up then dumped back in for the next town/city downriver to do it all over again. There's a limit on how much you can pull out before the costs to clean it up to standards get out of hand so forcing the use of more efficient appliances helps everyone. There's a big society cost to excessive use not covered in the price of the supply. There are lots of older, water wasting toilets that don't flush as well as many of the new ones, too.

    Using a non-standard rough-in doesn't make a standard 12" toilet unusable, it just leaves more room behind it to the wall. Some don't have a problem with that, but in a small room, it can be a big factor, and some just can't stand the look. And, if you have a good inspector, he might be kind when he writes up the rejection slip, but by then, your chance to do it right just cost you lots more than doing it now.
  11. Terry

    Terry Administrator Staff Member

    Messages:
    15,130
    Location:
    Bothell, Washington
    And yet there are plans to sell trips to the moon for the right price. Imagine how much pollution the regular folks have to put up with so rich people can day trip to the moon. We EPA our cars and will soon require that they get 50 MPG, but if you're rich, The skies the limit, well may there is no more limit for them.

    In the Seattle area, we depend on the snow pack in the mountains. There have been years when water was rationed. They don't worry about your toilets, but they do have a program that offers rebates to replace them.

    During rationing, people were cutting neighbor's hoses if they saw them watering lawns.
    Last edited: Dec 10, 2012
  12. Terry

    Terry Administrator Staff Member

    Messages:
    15,130
    Location:
    Bothell, Washington
    Here is a closet bend in an old Seattle home, using the 4x3 spigot closet bend and a 4" hub flange.

    [​IMG]

    And this is the toilet that was installed afterwards.

    [​IMG]

    TOTO CST423SF Promenade with round bowl.
    Last edited: Dec 11, 2012
  13. AlanS

    AlanS New Member

    Messages:
    1
    Location:
    British Columbia
    Not so. Australia, New Zealand, and most of the South Pacific nations (excluding parts of Asia) use 100mm/4" exclusively. They don't use the wax ring/flange system either, in NZ/Aust at least, they tend to use a receiver in the floor - basically like the wide part of a 100mm pipe, with an O-ring that the horn of the toilet inserts into. No messy wax to remove or melt in extreme temperature, no spills etc.
    A vastly superior system, IMHO. Rarely do you get blockages because the toilet throat/bend is 100mm as well, rather than the North American setup which appears to be modeled along the average size, to put it crudely, of a turd with little extra clearance.

    I'm pleased to see Caroma sell in North America, I'm kicking myself that I bought American Standard when I redid mine. These are not bad, using the vacuum sort of thing, but still prone to blockage. You can still have water efficiency with a less trouble-prone setup. Let's face it, it's not 'water-saving' if you have to flush multiple times.

    Just my AUD $.02
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,153
    Location:
    New England
    FWIW, the outer rim of the toilet flange is the same, whether it is 3 or 4" pipe, at least if you want it to fit on any US drain lines and toilets sold for this market! Agreed, though, that the Caroma can flush bigger/longer material than most others, but those sold in the USA will work on either a 3 or 4" drain pipe (could be different than those sold elsewhere). While we get visitors from outside NA, the vast majority are from here, and the advice is geared more towards that market.
  15. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,837
    Location:
    Cave Creek, Arizona
    You state that your toilet uses a flush elbow, therefore the roughin can be whatever you want within the limits of the flush ell. But, I don't know anyone who would still want to deal with a wall hung tank and flush ell these days.
Similar Threads: size toilet
Forum Title Date
Plumbing Forum, Professional & DIY Advice Toilet stub is too short and wrong size Oct 30, 2012
Plumbing Forum, Professional & DIY Advice Vent size two toilets Jan 3, 2012
Plumbing Forum, Professional & DIY Advice Toilet Supply Size From Wall... Feb 7, 2011
Plumbing Forum, Professional & DIY Advice Odd Size Toilet Flange Jun 11, 2008
Plumbing Forum, Professional & DIY Advice Best toilet flange size May 11, 2008

Share This Page