Replace Cast Iron Toilet Flange or not?

Discussion in 'Toilet Forum discussions' started by diverdave, Apr 21, 2013.

  1. diverdave

    diverdave New Member

    Messages:
    4
    Location:
    North Carolina
    I am remodeling a bathroom and planning to tile the floor. I laid the first layer of underlayment and now and I realize I made a mistake by cutting out the hole for the toilet flange too large. I cut it to fit over the flange so the flange won't be sitting on top of the underlayment. So that got me to thinking how would I fit the underlayment round the cast iron pipe correctly, or should I just replace the old flange altogether. I still have to add a layer of 1/4" CBU and maybe another layer of plywood, I had to add some height to the floor. So my questions are:

    1. How would I fit the plywood tightly to the cast iron pipe? Would I have to cut the plywood in half with a half circle on each side and fit it together around the pipe?
    2. Or is it best to just go ahead and replace the flange now with a PVC flange and Fernco type coupling to mate to the cast iron? The house was built in 1974 and this is the original flange. There doesn't seem to be anything wrong with it, its just old.
    3. If its best to replace the flange what is the best way to cut the old one off? Sawzall, grinder? How far below the floor would I cut it off, there is a crawlspace below so there is plenty of space to work with?

    Thanks

    P4200058.jpg P4200059.jpg
  2. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,249
    Location:
    Land of Cheese
    Don't cut anything unless you need to change the height more than 1/2".

    The flange has a ring of lead which was poured in right there, sealing it to the pipe. You can drill a bunch of holes in the lead and peel it all out, then the flange will come off.
  3. diverdave

    diverdave New Member

    Messages:
    4
    Location:
    North Carolina
    Great, thanks! I hadn't noticed the lead b/c there was still a bunch of wax covering it. I see how it is attached now and I should be able to remove it.

    I have a similar question for my shower. I was able to get the drain off (there was also a lead ring around that old drain) and now there is 2" copper coming out of the rough-in hole. I was planning on going with a PVC drain for the shower, should I cut that 2" copper below the floor and mate the PVC shower drain to the copper with a Fernco coupling? If so, how far below the floor should I make the cut?
    Thanks again
  4. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,419
    Location:
    North Vancouver, BC
    The fitting looks like it has a crack in it? Is that the case?
  5. diverdave

    diverdave New Member

    Messages:
    4
    Location:
    North Carolina
    I don't think it is cracked. I just looked at it again and it looks like it was made that way. All of the other holes are through the metal but that one that you see in the picture has the side cut out. Would it matter if it is cracked, wouldn't I be replacing it with a PVC flange?
  6. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,419
    Location:
    North Vancouver, BC
    Cast iron is very heavy and very brittle. It can crack easily. I would be worried about securing this flange. But are you replacing it?

    JW
  7. diverdave

    diverdave New Member

    Messages:
    4
    Location:
    North Carolina
    I was able to easily get the metal flange off and I examined it closely and it doesn't look cracked. The pipe that it came off of is 4" copper. I was anticipating that I would have to replace the metal flange. What would be the best thing to replace it with?
  8. Smooky

    Smooky Member

    Messages:
    624
    Location:
    NC
Similar Threads: Replace Cast
Forum Title Date
Toilet Forum discussions Broken Cast Iron Flange too Deep for insert replacement Sep 28, 2011
Toilet Forum discussions Do I Need to Replace this Cast Iron Flange? Nov 21, 2010
Toilet Forum discussions Cast iron flange replacement Sep 22, 2010
Toilet Forum discussions How do I replace a cast iron flange? Jun 30, 2010
Toilet Forum discussions Can you use Twist-N-Set® Cast Iron Replacement Closet Flange Jan 16, 2010

Share This Page