Toilet Flange Sizing

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LLPA

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Hello!
I am about to install a toilet in a brand new bathroom in a finished attic space.
The plumbing was roughed in months ago by plumber.
Because we had to build up the floor a little with more subfloor + Ditra + porcelain, the toilet drain elbow is a bit too low for the regular flange outlet.

The elbow hub in the floor has an ID of 3.5".
2024-12-06 07.21.14.jpg

So...my plumber dropped off a section of 3" pipe to use in between as a coupler, plus another flange (that is ID 2.5").
2024-12-06 08.40.55.jpg


Is that okay or too narrow for flow? OR IS there a flange with an ID of 3" that has a longer outlet?
Thank you!
 

Breplum

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If the flange assembly has a UPC emblem embossed on it, then nothing to worry about. Beyond that assurance, then the mfr of that offset flange is either unreliable or a bit dumb. The normal I.D. of 3" pipe is just over 3"...it could work but it would not be something I'd have anything good to say.
 

LLPA

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Is there a flange the size I need with longer outlet?
Or is it okay to use one that is 2.5" (see photo and adding 3" pipe cut down (as a sort of coupler)?
 

Reach4

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s that okay or too narrow for flow? OR IS there a flange with an ID of 3" that has a longer outlet?
A flange with an ID of 3 inches would be called a "spigot" type -- same ID and OD as a piece of 3 inch schedule 40 pipe. The are intended to go into a hub.

How long of a tail do you think you would need? https://pexuniverse.com/sioux-chief-886-ptms-total-knockout-tko-pvc-closet-flange is 2 inches tall overall, so the tail would be around 1.5 inches. That has a stainless ring. Note that the makers have been dropping flanges with stainless rings and keeping the all-plastic one. So the 886 is out of stock some places.

I would avoid gluing in an all-plastic flange, but they usually work out ok.

Can you fit an outside 3 inch closet flange? You would need that 3 inch pipe, but you need some height and side clearance.

plumbest C40-320 3inch pipe outside. 2 inch deep.
Code Blue No Caulk Closet Flange *outside*

Jones Stephens C40320 3 pipe x 2 depth ***
 
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LLPA

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I literally just need an extra inch...so flange with 4" outlet.
But my plumber also said this today regarding the 2.5" size of flange outlet:
Yes, the trap in a toilet is only 2 1/2". We use them all the time with no problems.
So i guess it's okay?
 
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