Rough-In Question from Novice

Discussion in 'Toilet Forum discussions' started by jksea, Mar 27, 2009.

  1. jksea

    jksea New Member

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    3
    My desktop is littered with spec sheets for toilets requiring 12-inch rough-in. In many of these cases, no part of the toilet is closer than 4" to the finished wall. So - why is a 12" rough-in required? Why not just 8", enough to keep the toilet from touching the wall? Obviously I'm missing something here! Thanks!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Are you looking at the tank as well? It would be a rare toilet that declared itself as a 12" rough that had 4" to the wall from the back of the tank...now, on the base, that's a different thing. Most have anywhere from 1/2 to 1.5" of space behind the tank to the wall.
  3. Gary Swart

    Gary Swart In the Trades

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    Rough-in distances for toilets is an interesting topic. Toilets are made for 10" 12" and 14" all distances measured from the finished wall to the center of the drain. So far, simple enough. However, in actual practice, many drains are not set at any of those distances and if that's not enough yet, many toilets will fit very nicely in less space than there rough-in dimensions. The most common rough-in size is 12" and you will find more choices in styles in that size. Of course, you can always set a toilet with a small rough-in in a large space, just live with the extra space behind the toilet. I don't know of any toilet that is classed as a 12" that when set on a 12" rough-in will leave a 4" space, but most toilets will leave some space. My Toto Dartmouth for example is on a 12" (exactly) rough-in but has over 2" between the tank and the wall. Go figure. In other words, it's not an exact science.

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    Last edited by a moderator: Apr 13, 2009
  4. jksea

    jksea New Member

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    3
    Specs

    One of the toilets that is confusing is the American Standard Right Height Elongated Toilet, model 2386.012. The spec sheet at americanstandard.com seems to show more than 3" distance from the wall for both the tank and the bowl. So I couldn't figure out why I need 12" rough-in. Confusing, indeed.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Do a search here on American Standard and you might reconsider!

    It may be that their QC is so poor, they leave more room than needed to account for inconsistencies in the parts.
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