I am replacing a toilet on a concrete floor in my basement. I plan on tiling the floor so I want to tile first and then replace the toilet so it sits on top of the tile. I removed the old toilet and found a cast iron drain pipe, a mangled metal flange and some type of rubber stopper the previous installer must have used to fit the toilet on. I know the drain size is 3" because when I removed the stopper, I inserted a 3" piece of PVC pipe into the drain to check the size and it fit perfectly, nice and snug. Can I attach a 3" toilet flange directly to the cast iron or are there other considerations that I don't know about? What would be the best way for me to go raising it high enough for backerboard and tile? I'm using Schluter-Ditra for underlayment. Thanks for any help.

massplumber2008

Hi Wmorg55:

If it is possible to post a picture here I could tell you EXACTLY what you need, but usually the following will work:

You'll want to install the tile first and then install a TWIST AND SET FLANGE....or a similar cast iron to PVC flange with screws inside the flange to pull up on the outer neoprene sleeve (2nd and 3rd images).

Dry fit the flange to be sure you are all set. Then, after the tile is installed install the new flange and secure it through the tile (will need a 1/4" masonry drill bit).

Let me know if you have questions...

MARK

Attached Images

   

WMorg555

I have a 3" PVC pipe that fits exactly into the drain without the stopper. Can I seal a plastic toilet flange to it and stick it deep into the drain. Will that work? Enclosed is a photo. The rubber stopper the previous installer used is on the right. Thanks for any help.

Attached Images

 

iamgrowler

That isn't a stopper -- It is a part of the old wax ring and should be thrown away.

The Twist and Set flange mentioned earlier really is your best option.

massplumber2008

Like Iamgrowler said...throw out the old wax ring horn (black plastic piece) as that is not required here.

The pipe doesn't look deep enough for a twist and set flange to work so I'm thinking that you will be better off installing closet flange extenders (comes as a kit most of the time) for your situation...see images. There are a few different kind...I do NOT recommend using spacers without the neoprene or foam gaskets!!

Here, clean the old flange extra well and remove the old closet bolts. Then you will install the spacers as directed on the package, but you will also need extra long closet bolts. The extra long closet bolts will insert through the bottom flange (present now) slots and then through the other spacers slots as well.

Click on the closetflange2.pdf file to see this all up close....

You can install so the flange is flush with the tile or even better on top of the tile...either works fine. If you go flush with the tile use an extra thick or a reinforced wax ring. Otherwise, a wax ring with horn is best bet.

Let me know if you have questions...

MARK

Attached Images

  

Attached Images

closetflange2.pdf (96.1 KB, 62 views)