Should I replace corroded cast iron toilet flange during remodel?

[Adam R.]

Hi, I'm remodeling my master bathroom and I'm looking for advice on what to do with the toilet flange. The house is ~50 years old and the existing flange isn't cracked or broken, but it does look badly corroded on the inside of the flange and pipe. I was originally planning to leave it as it is, but I'm concerned about it leaking in the future. I don't really have a way of measuring how much wall thickness is left. I'm thinking that my options are:

1. Leave the existing flange there and hope for the best. I'm not that comfortable with this option because I would hate to have it leak and drip down on the first floor.
2. Cut the 3" cast iron pipe on the horizontal run a few inches before the hub at the stack. Then I would put in a new ABS flange and pipe and connect to the existing cast iron pipe using a Fernco type rubber coupling.
3. Cut/chisel the old cast iron pipe out of the hub at the stack. Then put in new pipe to the hub. I'm not familiar with what the best practice is for sealing a new pipe into an old cast hub like that.

I'm leaning toward option 2, but would appreciate any advice. Thanks.

 

[Terry]

The house is ~50 years old and the existing flange isn't cracked or broken, but it does look badly corroded on the inside of the flange and pipe. I was originally planning to leave it as it is, but I'm concerned about it leaking in the future. I don't really have a way of measuring how much wall thickness is left.

Always a good question. The question would be how far to go, and why?
At some point, all cast pipe will need replacing. How long it will last is tough to say. The kitchen lines are the quickest to go.
Option A would be the fairy easy for now. Though as often as I'm replacing toilets, I'm mainly just using the piping that is already there.
If it's the old size cast, something like a + 1/8 size, then I use a copper by plastic coupling.

 

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[CountryBumkin]

That pipe looks pretty solid to me (but I'm not a plumber). I would just leave it alone. It looks like to could go another 25 years.
You may create more trouble for yourself by messing with this.

"Better is the enemy of good enough"

 

[Reach4]

It looks like to could go another 25 years.

I would think 80 or so.