Toilet Flange Installation for Dummies?

Discussion in 'Toilet Forum discussions' started by dan_public, Jul 7, 2006.

  1. dan_public

    dan_public New Member

    Hi. I'm a newbie here and have limited plumbing experience. I need help with a toilet flange - I think it needs to be replaced.

    I'm remodeling our bathroom and replacing the bathroom particle board subfloor with two layers of plywood. On top of this will be a Schluter Ditra uncoupling and water proofing layer, and then tile. The layers will look like this:

    - Tile
    - Ditra
    - 3/8 Plywood
    - 3/4 Plywood

    The current toilet flange (see pic below) is screwed into the particle board and connected to ABS. The new plywood layers + Ditra will raise the flange level by at least 1/2 inch. So...

    1) Do I have to replace the toilet flange? (I think "Yes" because of the new, higher subfloor.)

    2) Should the flange be placed on top of the Ditra layer and screwed through to the plywood, or should the flange be screwed to the plywood and then Ditra wrapped around it?

    3) Where can I find a "Toliet Flange Installation for Dummies" how-to? :D

    Thanks in advance for any help.


    p.s., I have limited plumbing experience but have worked with PVC and ABS.

    Attached Files:

  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    New England
    Since you are redoing the floor, install a new flange on TOP of the finished floor, like it is supposed to be done. To make things easier, notch the tile on the wetsaw or with a grinder prior to laying them down so you don't have to try to drill through them to mount the flange through the tile into the subflooring. When finished, the flange should be firmly attached to the floor and not have a gap underneath it. this is much easier if you have access to the pipe from below to allow you to cut off the old one and a little pipe, then patch in a coupling, straight piece and a new flange. You can do it with an internal cutter from above, if required. Depending on the flange, you might not need a coupler and a short piece of straight pipe if it has a long enough neck.
  3. plumber1

    plumber1 Plumber

    This should be an easy plumbing project for you. You don't need any new parts.

    I would put a propane torch on the inside of that brass flange and sweat it off the copper stub. You need to get the flange quite hot. You don't need to get the flame any wood surface at all.

    Then clean the inside of the flange while the solder is still wet and also wipe the outside of the stub.

    Then after the new floor is down you should be able to slide that same flange back in the pipe. and once you've soldered it back on and before you set the toilet, if there is a little excess pipe sticking up, you can pean it back to the bevel of the flange.

    You'll just need some emory cloth a little solder and flux because the flange and pipe are already tinned.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona

    It is not a copper flange and pipe. It is an ABS flange with a rotating metal flange, glued to a 3" riser. An experienced plumber would probably be able to remove the flange and then make any modifications necessary to raise it.
  5. dan_public

    dan_public New Member

    Is this not an easy project?

    Hi. Thanks for the feedback.

    Yes, I believe the flange is glued to an ABS pipe. Regarding brass, I assume plumber1 is referring to orange part in the pic. (I don't see any brass fittings although I could easily be mistaken.) Also, the flange and and piple can be accessed from below. (It's just a matter of cutting a section of drywall out of the garage ceiling.)

    Since the flange is more than 20 years old, I'd like to replace it with a new one. They are only about $5-$10 aren't they?

    Given my situation and based on your feedback, it sounds like the process to install a new flange is:

    1) Cut off the current flange at the highest point possible in the ABS pipe.

    2) Install subfloor and Ditra.

    3) Cut a hole in the subfloor and Ditra the OD size of the ABS pipe.

    4) Cut tile to fit around hole and dry fit flange to ensure it is level and the flange slots line up with toilet bolt holes.

    5) Mark flange screw holes on tile and cut slots in tile for flange screws.

    6) Install tile.

    7) Install flange and glue to ABS pipe using coupling.

    8) Install toilet.

    Does this sound about right?


  6. Terry

    Terry Administrator Staff Member

    Bothell, Washington
    That's about right,

    You will need to cut the hole to the size of the closet flange, not the pipe.

    You can't dry fit ABS.
    With the glue on both pieces, it won't slid together.
    And once you put the glue on and slid it together, it won't pull apart again.

    Just measure the depth of the hub and make it a wee bit shorter.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    New England
    Terry meant without the cement, it won't fully dryfit. If you were able to get it all the way seated, you might not be able to get it back apart.
  8. dan_public

    dan_public New Member

    Great feedback! Thanks.

    That said, I found something else about the toilet plumbing. It looks like the drain and vent connections are very close to the flange. I'll take pics and post tomorrow.

    Thanks again,

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