First time shower build.

[Jadnashua]

If, after you clean it off, it is thin or fragile, or has parts totally rusted away, you need to do something to it - probably replace. If it is solid, and you get a good seal with the wax, it could last another 50-years. See if one of the plumbers responds - I'd take their experience...but, CI works, is quiet, and can last a very long time. Under marginal conditions, it might also fail in a decade or two as well. Terry has indicated when people don't flush overnight (probably because of the noise), that the urine, being heavier than water, can partially drain, nearly undiluted. He's shown pictures of the bottom of the pipe literally eaten away. If the pipe is solid and the flange is solid, it should be okay. The only other issue is the height of the flange once you get the new floor installed. Ideally, the flange would be on top of the finished floor, but as long as it isn't recessed too far, it can usually be dealt with.

 

[Brihen]

The flange seems to clean up pretty well I think. Most of the rust is inside the pipe, but it is a thick pipe.

 

[Sponsor]

 

[Brihen]

The floor will be a little higher. I think maybe 1/4" I hope a thick or double wax ring will do it. I want to cover the 1.5" t+g with 5/8 pw 1/4 cbu and 1/4 tile. It had 3/4" particle board and vinyl sheeting, over the t+g.

 

[Jadnashua]

A plumber could replace the flange and the toilet elbow with new cast iron if you chose, and then you could end up with it on top of the finished floor. Leading in a joint takes special tools and skills, especially on the horizontal most DIY'ers do not have. THe alternative is to tear out the CI to the hub shown, and replace it, but you may not have the height to make it all work well - I'm not sure you can replicate that bend in plastic with available parts, but a plumber would know. Making the joint into the hub could be done with a properly sized donut (compression fitting), or, if you cut the hub off, a banded coupling. I don't think you need to go that route, but I do not know for sure.

You could save a little bit in height of your floor buildup if you went with Greenskin or Ditra (or something similar) - the Greenskin is thinner than Ditra, and Ditra works out to about 1/8".