15.5" rough in, current toilet size unknown

Discussion in 'Toilet Forum discussions' started by yeoldmoneypit, Aug 10, 2018.

  1. yeoldmoneypit

    yeoldmoneypit New Member

    Joined:
    Aug 10, 2018
    Location:
    Newport, KY
    I've had 3 different plumbers here recently. A new toilet is definitely needed but there is no consensus between the plumbers on my current toilet size. Two say it's a 12" toilet, one says it's a 14". How do you measure the toilet itself, NOT the rough-in? Is it the distance from the back of the tank to the bolts? If so, current toilet is a 12". Back of tank to the wall is 2.25". It matters because my options are considerably fewer if the current toilet is a 14" rough-in. I can live with the distance of 2.25" away from the wall but not more. It's an old house, small bathroom, space is an issue. It's hard enough finding a small toilet.
     
  2. wjcandee

    wjcandee Wise One

    Joined:
    Apr 27, 2012
    Location:
    New York, NY
    The answer is that you don't measure the toilet.

    There's no such thing as a 14" toilet. There is only a toilet that is designed to go on a 14" rough-in.

    There's no such thing as a 12" toilet. There is only a toilet that is designed to go on a 12" rough-in.

    The phrase, "12-inch toilet" is just shorthand for one that goes on a 12" rough in. Same for 10" and 14".

    The important thing to know is the rough-in, which is the distance from the finished wall to the center of the closet flange.

    You then look at spec sheets for the toilets to see what the distance between back of tank and wall would be when mounted on an X-inch rough-in.

    These vary considerably. For example, the Toto unit with the integrated washlet that is not a Neorest model requires a full 12"-inch rough-in. If the rough-in is 1/4" less than 12", the toilet (in theory) won't fit because it will be pressing against the wall. The Toto Original Drake, in contrast, leaves more than an inch behind the tank when mounted on its specified 12" rough-in. Accordingly, people like me whose so-called 12" rough-in is actually 11" in one place in the house can mount the Original Drake on that rough-in and still have a little gap behind the tank.

    Makes sense?

    One option is to buy one of the Toto toilets that uses the Unifit adapter. Not all do, and they're not the cheapest of toilets. But the Vespin II, for example, is affordable when purchased from a seller that discounts significantly off the list price, as many (including Terry) do.

    Most 14" rough-in toilets just use a bigger tank on a standard-size bowl, to narrow the gap between tank and wall. The body of the toilet is still sitting out well into the room.

    In contrast, the toilets that use the Unifit actually push the entire toilet back towards the wall, giving you more room in the bathroom. Terry has some photos on the site that show the difference. Some of our enterprising members have actually adapted the Unifit adapter to push the toilet back even further from the flange than would be necessary for a perfect fit on 14". So if they have a 15.5" rough-in, they have extended the Unifit another 1.5" to fill the gap even better. It's a massive Kluge (or what WWII guys used to call a "Jerry rig"), but if they get it so it works, who's to criticize?
     
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  4. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Usually it would be distance from the back of the tank to the bolts plus maybe 1/2 inch or so. However in your case, it is probably a 12 because that is a standard size.

    I would get a Vespin II with a 14 inch Unifit. That would give you more floor space in front of the toilet, in addition to not having the big gap. However if you want to spend significantly less, get a 12 inch toilet, and keep a gap. It's not a long term commitment. You could change the toilet in a few years as the cash becomes less tight. Toilet mounts on the floor tiles. Don't bring the tiles up to the toilet base and stop.
     
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    Think of the rough-in on a toilet as the minimum distance from the wall to the center of the drain. A 10" rough-in toilet is guaranteed to fit on a rough-in that is at least 10", but would still work on one where the rough-in was much larger...what happens then, is that the toilet would have more and more room behind it.

    If your rough-in is 14" (you won't know until you measure), the most common toilets (12" rough-in) could have anywhere from at least 2" to nearly 4" of space behind it corresponding to zero gap to 2" if it were mounted on a true 12" rough-in.

    FWIW, the Vespin is designed to have a 3/4" nominal (meaning it could vary slightly for manufacturing tolerances) gap behind it when install on the designed rough-in flange. By picking the proper Uni-Fit adapter, that series of Toto toilets will stick out from the wall the same distance when installed on a 10, 12, or 14" rough-in and corresponding Uni-Fit adapter (it comes with the 12" one, you'd have to buy a 14" one).
     
  6. yeoldmoneypit

    yeoldmoneypit New Member

    Joined:
    Aug 10, 2018
    Location:
    Newport, KY
    Thanks everyone, for your helpful explanations. Hard to find a plumber in my area experienced and comfortable installing the Uni-Fit adapter in my 100+ yr old house. (I've been told it would be a can of worms.) I even called Toto for advice on finding someone with no luck. I appreciate the input, though!
     
  7. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Not so hard. For a beginner, it is probably easier than a regular toilet. For somebody used to doing regular toilets, it would take extra time.
     
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    To install a Unifit adapter...you set the thing on the flange as if it were the toilet with a wax ring, then screw the rear of the adapter to the floor. If the floor is tiled, that can take some extra time as drilling holes in tile can require special tools (usually, a diamond core bit). Once that is installed, you set the toilet on the adapter and fasten two bolts to attach the toilet to the adapter...IOW, it's pretty simple, assuming the installer is not too proud to actually read the instructions and thinks he knows it all. Because the toilet is skirted, the location of the water supply is critical, otherwise, it might not fit, but there's nothing unique about that, either. All in all, for someone that isn't a clutz, with the right tools, it might take an extra half hour or so, and possibly less. Some tile is a bear to drill a hole in and it takes some time. There are few toilets designed to project into the room the same as a conventional 12" one. A Toto with the Unifit uses the exact same toilet to fit exactly the same distance from the wall on a 10, 12, and 14" rough-in. Every other one will stick out further, and that can be a big issue in a smaller room, or where a door is in the picture.
     
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