The flange in the accompanying pics is original to my 70-yo house. There are a few places along the inner rim of the flange that are lower than the overall surface. The largest is at the end of the green straw and still partially filled with wax. The outer rim of the flange is a complete, flat surface to form a seal. I am guessing that these defects are original to the construction and not a problem - is that correct?

My real concern is that I notice that the bottom of the flange is about 1/4 inch above the subfloor so it is not supported (note putty knife under flange). The rim of the original toilet (which I am replacing) sat on the floor and I believe exerted no pressure on the flange. Attempting to seat the replacement toilet (similar vintage, both American Standard) the toilet rests on one side of the flange. I think the flange is out of level by not more than about 1/16 inch. Measureing the depth of the recess in the toilet bottoms, the replacement appears to be about 1/32 to 1/16 inch shallower (hard to make that measurement accurately).

Is it OK for the toilet to be partly supported by the flange? If not, are shims or something like grout under the flange OK or should it be replaced? I could also add some support to the cast iron pipe under the floor but I presume that along would not be adequate.

Thanks!

the toilet should rest on the floor NOT on the flange

dry set the bowl

pencil outline along finished floor

make four 1/2" wide cardboard shims from multiple pieces and level toilet so it sits level on the shims juuuuust above the flange

make a ridge of plaster of paris inside the pencil marks and without disturbing shims - LEAVE SHIMS IN PLACE - (you can color plaster to match floor or toilet color if desired) and set bowl as normal squishing into plaster and resting on shims

when plaster sets (15-20 minutes) remove shims and plaster holes where shims were

voila: old school installation to match the old school piping

toilets discharge like a fire hose:



the purpose of the wax 'seal' is merely to stop gasses (theoretically)

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

tom, if the flange is original from the 70's then you are living on borrowed time.
stuff the pipe with newspaper and bash the flange to pieces to remove it.
just hit outwards on the flange and it will break apart.
then replace it with a push-fit flange like this..
smear a touch of bowl wax on the rubber to help it seal.
also make sure the bolts are solid brass, not plated steel.

Packy, I should have been clearer. The flange, and all piping, are 70 years old. Given that, do you agree with bernabeau or do you recommend a different approach?

Bernabeau, your recommendation sounds exactly right for me. However, I am concerned about the plaster of paris setting too quickly, even if I add baking soda to slow it down. I looked at Home Depot's web site for an alternative product that might work, particularly something that I might be able to apply using my caulking gun, but did not find anything. Can you suggest an alternative with a slower set-up time? Thanks.

remove the old flange as it will sooner or later grack at the bolt openings.
use the flange i showed and use clear silicone to seal around the base. tom, this is what happens tp old cast flanges.

Tom,


you 'could' use 6 of the 'modern' plastic toilet shims and leave them in place (trimming them flush of course) and simply caulk with silicone using a 'gun'


then the toilet would rest on the shims but be (well?) supported by the caulk


IMO: the plaster of paris is actually easier

dry fit and level everything first

place wax ring on bowl - place bowl with ring on some scrap wood upright next to/near flange

put (matters not how sloppy) bead of plaster inside pencil mark

set bowl - you have 5-8 minutes to move bowl

as soon as the bowl is set you can IMMEDIATELY wipe/form plaster

in 10 minutes remove shims and final trim


??? ARE YOU DONE YET ???



==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Most "plumbers", myself included, would "bash" the old flange and lead/oakum a new one on set properly to the floor,

the OP is NOT a plumber

while we could describe how to use lead wool to avoid pouring liquid lead the OP is NOT equiped for the possible "awww sheeiiit" if something breaks 'down below' because of the mallet blows to the cast iron flange


@OP,

do it the way i suggested - simpler and BEST in the long run

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Bern I see your point about the easier more diy approach but if I pulled that toilet sometime down the road I'd be pissed to have to fix it the way a plumber would what a mess, I agree with packy, no offense

The ORIGINAL toilet done in the 70s most likely WAS set on a tile floor on a bed of plaster.

That IS the way we plumbers set toilets in the olden days.


SHEEEEZ

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Well, I go back to the FIFTIES, (U.A. 130, Chicago), and NEVER did it that way.



Edited 1 times.

What about the porosity of plaster, absorbing liquid and holding onto that funk?

same as the grout used in the tile floor

unless, of course, one spent the time / momey / effort to seal same




one 'could' use mortar BUT then the next guy was scr#*ed

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Everyone, I appreciate all of the discussion. I am the kind of guy who likes things done right but tackling the flange is too big of a leap to do myself. Now I need to decide whether to spend $10 to do it the way bernabeau recommended or hire a plumber to replace the flange. I will let you know how it comes out.

bernabeu, my only use of plaster of paris was decades ago and I recall it setting much faster than that - must of been too dry of a mix. Thanks for the additional info.

if mixed appropriately you will have 10+ minutes to set bowl before it sets


sorry, i don't remember the 'formula' - but - wet is fine, the shims support until dry anyway


ps. the point of the cardboard SHIMS vs. plastic WEDGES is they (cardboard) will not 'move around' or need adjustment after setting the bowl thereby potentially breaking the wax seal

pps. when laying the plaster try to put it mostly INSIDE the pencil mark so you have a clear target when lowering the bowl into position


??? ARE YOU DONE YET ???




==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638