New Toilet Flange Installation

[Ray]

I have a question before embarking on the roughing in of my toilet flange before pouring my concrete. I envision leaving some standpipe sticking out of the concrete and once the concrete cures cutting the pipe flush to the floor to accept the toilet flange. The toilet flanges that I came across only mount to the outside of the pipe and that wouldn't work if the pipe is cut flush. I quess the only other option would be to have the flange already in place prior to the pouring of the cement. Is this a correct assumption ?? What happens if the flange screws up down the road and the joint is below the concrete surface ??

I was hoping that I would find a flange fitting that would mount to the inside of the toilet standpipe. Is there such a thing ?? Thanks, Ray

[Mark Monson]

Hello again Ray.

The trick set-up is a 4x3 closet elbow. You stub up through the slab with

4" pipe. This you whack off after the concrete gets hard and glue in your 4x3 closet flange. It will fit inside the 4" pipe.

[Ray]

Mark, So just so I know I'm getting this right; the 4x3 flange will fit inside the 4" stub which goes into the 4" side of the elbow that is reduced down to the 3" side which is continuing on to the drain pipe ?? Thanks, Ray

[Mark Monson]

You got it.

[Ray]

Thanks for your valuable input and have a Merry Xmas. Ray

[runningwater]

,

man this is confusing...

[Mark Monson]

I should add that normally you never decrease the size of the drain pipe. The only place you can do it is under the water closet and you have to use a specially made 4x3 closet bend, NOT a 4" el with a 4x3 bushing.

[Ray]

You lost me on this...The 4x3 flange has the 3" side up to the toilet sitting on the slab and the 4" side down inside of the 4" stub pipe. The 4" stub pipe is fitted to the 4" side of the elbow and the 3" side of the elbow is where I run my 3" drain pipe with grade towards the city line or septic tank. How on this ??

Ray

[Mark Monson]

The 4x3 flange is made so that it will either glue on the inside of a four inch pipe or on the outside of a 3 inch pipe. The rest of it you understand.

[Ray]

Thanks, I understand now.... Ray

[Ned Flanders]

And agianst code in my state.

I have some plastic caps designed for just this purpose. They slip over the standpipe have a foam sleeve that when removed leaves a clear gap around the flange. The ones I got are cool because they leave enough cement around the flange to ancor to, but dont impede on the underside of the flange at all. If I am out of them I take a bit of 4" sch20 PVC and use it to keep the cement away from my drain.

[Mark Monson]

What is against code and in what state?

MM

[Blackbeard]

Well before you worry about the concrete, need to make sure you get the rough measurements right. Measure 15" off the wall beside the toilet. Make sure you allow for FINISHED WALL (add 1/2" if your coming back with sheetrock...add closer to a full 1-inch if your coming back to do the walls with tile.

That said, code only requires a 3" standpipe for that toilet. Stub the pipe up high enough to pour around it. Use some insulation and wrap it around the pipe (you want about 4-1/2 inches so the flange will fit). Tape the insulation with duct tape...pour your concrete...after it hardens, pull the insulation out and you'll have room for your flange. Swimming Floaties also work well (the thing kids wear on the arms at the swimming pool). You can use the larger sized. Inflated, they are the perfect size...and you can use them numerous times.