Toilet Flange will be too low

[JamesScott]

Hi All,

I laying tile in my upstairs bathroom. With the new install my flange will sit below the floor, probably around a quarter inch. What steps do I take to extend the flange so that it will sit just above the tile job?

I am not sure what type of flange it is - My house is older and it looks like a cast iron flange that is an extension of the pipe. It is 4 inchs. It is not screwed down into the subfloor, but it is firm. I purchased a PVC flange extender kit from Lowes and I am wondering if this will do the trick.

Per the kit instructions, I need to screw the extender into the subfloor, but the slots of the screw sit on top of the old flange, so that's not an option.

Can I use some sort of PVC cement to adhere the two?

Can I drill into the previous flange to create the holes for the screws.

Can I install PVC over the cast iron flange?

Any thoughts would be appreciated.

 

[Leejosepho]

Can I drill into the previous flange to create the holes for the screws.

Can I install PVC over the cast iron flange?

Sure, and I would use stainless screws and even machine screws if you have a way to tap threads for them ... and be sure the extension is well-sealed against the original flange.

 

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[Cass]

Is the inside of the pipe cast lron or lead.

If cast I would use an extended repair flange with a gasget that fits tight inside the cast iron pipe B 4 I would use the flange extender kit.

 

[Mike Swearingen]

Or, you can do what I did with the same situation when we tiled our upstairs and downstairs bathrooms back in '98...I raised the downstairs flange to sit on top of the tile (over a crawlspace) and just doubled up the wax rings upstairs. I used a regular wax ring on bottom and a wax ring with a plastic horn on top. It hasn't leaked a drop in 9 years.
I'm not a pro plumber, just a long-time DIYer. There obviously are other ways to solve the problem. That's just what I did with mine.
I have PVC flanges, and they are bolted to the floor. To be installed correctly, of course, the flanges should be bolted on top of the finished floor level with only the thickness of the flange above the finished floor level.
Good Luck!
Mike