5" inside diameter toilet flange - cast iron

Discussion in 'Toilet Forum discussions' started by k.look, Nov 28, 2004.

  1. k.look

    k.look New Member

    Messages:
    2
    I have a 5" inside diameter toilet flange that's 1 1/2" deep that's connected to a 4" inside diameter cast iron waste pipe. The problem is wax rings are made for 3" and 4" openings. Is there a wax ring for a 5" opening or what do you recommend to reduce the opening to 4"?

    Ken - Chicago, Il
  2. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Messages:
    319
    Location:
    Wichita, Kansas
    Regular Wax

    A regular wax should fit. The inside of 4" or 4 x 3 flanges are almost five inches. I have not hear of a 5" toilet flange.
  3. e-plumber

    e-plumber DIY Senior Member

    Messages:
    137
    Location:
    New York
    Wax Gasket

    Although I never had this problem...
    Instead of reducing the (closet flange) drain opening you would be better off combining a small section of a second wax seal to another one to make the diameter larger if that's what you need to do.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,251
    Location:
    Cave Creek, Arizona
    flange

    Apparently the 4" cast iron pipe is not long enough to reach the surface of the flange, the way it should. A plumber would caulk a section of pipe inside the flange so the new opening would be correct for a wax ring.
  5. k.look

    k.look New Member

    Messages:
    2
    flange

    EJ,
    What type of pipe do you recommend caulking in there? What will fit? A piece of iron pipe or PVC? I think if I reduced the opening down to an inside diameter of 4", the wax ring would give me a better seal in the long run so I don't have to repair the floor again. The plumbing guy at local Home Depot said this might be a commercial fitting that was put on my toilet.

    I just talked to a commercial plumbing supply house. Apparently my situation is common plumbing technique in the Chicago area. The flange is 5" diameter with a 1 1/2" drop connecting to a 4" waste pipe. A regular wax ring should do the trick. Apparently, the original installation had a plumber's putty like consistency that reduced this 5" opening to about 4" (this material was very stiff and flaking) when I originally removed it.
    Last edited: Nov 29, 2004
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,251
    Location:
    Cave Creek, Arizona
    5"

    The "5"" flange is really a 4" one, but the 4" pipe is too short. The best solution would be a 1 1/2" piece of cast iron pipe caulked, (leaded), into the flange to raise the 4" to the finish floor elevation. Failing that a piece of 4" ABS or PVC could be inserted and siliconed in place so it lines up with the existing 4" pipe.
Similar Threads: inside diameter
Forum Title Date
Toilet Forum discussions Inside diameter of Toilet flange too big! May 15, 2011
Toilet Forum discussions Inside of toilet PVC pipe has cut marks - an issue? Aug 23, 2013
Toilet Forum discussions exception to the rule about not using inside coupling closet flange on 3" ABS? Jun 1, 2013
Toilet Forum discussions Toto C744EG#01 does not feel smooth inside bottom of the bowl May 29, 2013
Toilet Forum discussions Am I supposed to use a metal washer inside the tank or not? Nov 25, 2012

Share This Page