Forum Discussion

SEJohn's avatar
SEJohn
Explorer
Dec 10, 2016

Flange to Black Tank

I had a leak at the toilet valve, which got to the OSB floor. It dried out well and the OSB is in good shape. The flange sat on the carpet/pad and I want to go back with linoleum. There is a 1/4" gap between the flange and OSB, so there will still be a gap with linoleum. I was able to rotate the flange so bolts will be in the right position - it was very hard to rotate. I can lift it up and push it down maybe 1/8" - not sure if that is the tank flexing or a seal flexing. Anyway, I'm not sure what to do here. Do I need to somehow pull the flange and install a new, lower one? If so, how do I pull it? Or, could a put a filler under the flange to fill the gap? If yes, what do I use and will the toilet still sit on the floor right? Original toilet was Thetford Aqua-Magic Galaxy. Thanks for any help.
Class C
  • SEJohn's avatar
    SEJohn
    Explorer
    Dec 12, 2016
    After spinning the flange 10 times or so without any change in height, I'm thinking that it is a slip fitting that was not glued. Its have pulled pretty hard while turning and it just flexes. I'm afraid that if I pull harder I will either break the tank, or not get the flange back in. So, I will put down a 1/4" underlayment and then linoleum. Thanks for all of the input!
  • j-d's avatar
    j-d
    Explorer II
    Dec 11, 2016
    It's been 06 years, so I forget. I used to do my RV parts shopping at Mobile Trailer in Anchorage and bring the parts back to FL. They had more stuff, better pricing and FAR more knowledge than other places I could find. I bought the flange they suggested, I want to say it was female threaded. Said it was the most common one. I really don't think it was male threaded, and in know it wasn't glued because it simply screwed on. Previous owner had a connection leak to the toilet, not the flush valve. OSB was rotted, and somebody'd cracked the Flange trying to tighten it and get rid of the wobble. My Toiled Floor Project made it to the WEB at RotDoctor.

    Some RV and Mobile Home toilet flanges are glued but threaded seems very common. I'm thinking that if OP can turn it, he can unscrew it. Then see if a different flange will seat farther down. Maybe clean the threads and it'll go a little farther. Maybe trim the flange or whatever it screws to.

    Notice my repair included a "Pedestal." That really helped, since it spreads the toilet operator's weight over a larger and different area than where the OSB has failed. Weight on the Flange and Tank is not a good thing.
  • dave17352's avatar
    dave17352
    Explorer
    Dec 11, 2016
    Must be different from the residential plumbing. The flanges are just glued. As the other gentleman said I would not force the flange anywhere. I would put down some underpayment to raise the floor so the flange is at the right height. Unless you are willing to re plumb the flange. I don't know what that would entail. But why couldn't you just shim up the flange and then lay vinyl? Just make sure to keep the flange supported. JMHO
    PS send some pics they help a lot!
  • j-d's avatar
    j-d
    Explorer II
    Dec 10, 2016
    Others will have details, but DO NOT force the tank into a distorted position. They tend to crack when the floor gets weak and the toilet wobbles with somebody sitting on it. Based on that, it doesn't make sense to assemble the toilet to the tank with a tweak in it.

    The common flanges are Female Thread, Male Thread and Glued. If you could turn it, must not be glued. You could probably unscrew it and see what needs to be done to drop the level of the flange.

    Again, others will likely have better suggestions

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