Cut flange over 3" pipe, and install 4" flange on top?

[Danny L]

Hi forum,

I'm in a bit of a pickle. I hired a professional plumber to install a toilet flange for me but he installed it 3/8 inches above the finished tile floor and claims it is perfectly acceptable. Further, the flange is only held in to the substrate by 1 screw and the flange rests solely on the pipe and not on any of the surrounding tile as the hole was cut too large. Obviously this isn't the correct install.

The flange the plumber installed was an "over the top 3 inch ABS pipe, or inside 4 inch ABS pipe".

My question is:. Can I cut off the existing flange at finished tile height, and install on top of the pipe remnants a new 4" flange? I'm not in the position to repair the ABS pipe below adding a coupler and new pipe as there is not enough space before I hit the 45 degree pipe.

The alternative if you think is best, is to leave the flange as is and just shim the toilet to support the difference rather than risk this fix. If it goes wrong, my old hope is to just use a inside 3" pipe flange.

Any obstruction (concrete) blocking the flange from going into the substrate below the tile floor will be cleared.

 

[Reach4]

I'm in a bit of a pickle. I hired a professional plumber to install a toilet flange for me but he installed it 3/8 inches above the finished tile floor and claims it is perfectly acceptable.

Is the underside of the ring 3/8 above the floor or the upper side? If upper side, you could probably shim under the ring, and add more hold-down screws.

My question is:. Can I cut off the existing flange at finished tile height, and install on top of the pipe remnants a new 4" flange?

Not sure-- I suspect yes. If you can glue the 4 inch spigot flange outside the remainder of the old flange, will there be clearance for the 4.5 inch OD tail?

 

[Sponsor]

 

[Tuttles Revenge]

If its a 4x3 without a bevel flange such as the Sioux Chief 884 PTM, You can cut the existing flange off, glue 4" pipe over the leftover barrel and install an "over 4" pipe" closet flange at the correct height.

However. you will need the clearance around the pipe to accommodate the added diameters

 

[wwhitney]

Seems like some of these solutions will create a horizontal shelf just below the closet flange that could catch solids. Is that a concern? If the opening at the top of the closet flange is only 3" like the 3" pipe below, then any sidewall void space could be filled with a small piece of 3"pipe, 3" over / 4" inside flange spigot end, and possibly 4" pipe.

Other options are an inside 3" flange. Or else getting a 3" socket saver type tool and reaming out the fitting hub below the closet flange.

Cheers, Wayne

 

[Tuttles Revenge]

Seems like some of these solutions will create a horizontal shelf just below the closet flange that could catch solids. Is that a concern? If the opening at the top of the closet flange is only 3" like the 3" pipe below, then any sidewall void space could be filled with a small piece of 3"pipe, 3" over / 4" inside flange spigot end, and possibly 4" pipe.

Other options are an inside 3" flange. Or else getting a 3" socket saver type tool and reaming out the fitting hub below the closet flange.

Cheers, Wayne

Theres no interference issues with adding diameters outside of the 3" inner pipe.. if that were the case then the 3" would be a problem. The toilet outlet is basically 2" over a 3"min opening and anything outside of that is just a wider target. The closet flange ring are standard diameters capable of differences between covering 4" to 3" pipe diameters.

 

[wwhitney]

Agreed if the design of the existing 3x4 closet flange allows for installation inside a 4" pipe cut flush to the finish floor. That's the way the one I have on hand is designed. Then the OP can cut the existing flange flush with the finish floor and have a nice 4" OD cylinder to connect to.

I also can imagine a (worse) design where installation inside a 4" pipe would require the pipe to be cut below the finish floor elevation, by an amount exceeding the 3/8" the current flange is too high. In which case cutting the current flange at the finish floor would leave a remnant bigger than 4" OD, and it would need to be cut below the finish floor to get to a nice 4" OD cylinder. That would create a shelf. [Which admittedly is still not a problem if it's close to the finish floor elevation.]

Probably just a non-issue I imagined, sorry for the distraction.

Cheers, Wayne

 

[Tuttles Revenge]

if the design of the existing 3x4 closet flange allows for installation inside a 4" pipe cut flush to the finish floor.

Perhaps that is the reason why the plumber wasn't able to get the flange down all the way? May have used the wrong style 4x3 flange?

Or the glue set up before it got all the way down, which is the reason I usually cut mine down to 1.5"

Or the flange barrel bottomed out on the beginning of the radius?

(full disclosure.. i've done all of the above but have never tried to claim any of those failures as successes.)

 

[Danny L]

Is the underside

Not sure-- I suspect yes. If you can glue the 4 inch spigot flange outside the remainder of the old flange, will there be clearance for the 4.5 inch OD tail?

Thanks. I did this exact thing. I glued a 4 inch abs pipe to the outside of my existing flange pipe once it was cut. I ended up installing an over 4" abs flange on top of that.