# what is the standard procedure for installing a closet flange on concrete?



## trav007

I've been asked by a friend to install a toilet for them. I've done a lot of toilets but never had to add a closet flange to concrete. I suppose I should just cut the pipe off flush with the concrete and glue in the flange. Is it just that simple?


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## rbsremodeling

We normally stub the pipe up couple of inches above the concrete. form a box around it pour the concrete and remove the box when the concrete sets up. That way we can adjust the flange as need to get a tight fit. I am sure there are other ways and recommendations


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## neolitic

Plumber sets it to grade and location,
then I duct tape top and  underside
of the flange and pour.
I tape the underside to keep a void 
for the flange bolt heads.


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## Double-A

Be sure to screw that flange down to the floor properly as well and make sure the flange sits on the concrete. 

There are as many ways to do this as there are plumbers. You've had two responses and two different methods.

One plumber I knew would wrap the closet riser in cardboard and just shove the end into the closet bend, keeping the riser short, so it would be buried in the concrete. Then, once the slab was poured, he would bust the concrete above it, dig it out, cut and glue in a proper length of riser with his flange on top. 

The concrete finishers were always leaving him a wavy floor otherwise, and his WC's would rock.


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## cleveman

Sharpie,

I don't want anything protruding up from the slab when I pour. Protrusions will only lead to unevenness.

Make boxes and put them about 1/4 or 1/2 below the surface. Seal them off.

Take photos with measurements off the forms.

Pour concrete. 

Tap around, break out your box.

Make plumbing connections, fill with sackcrete.


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## rex

sawzall with old 6" wood blade cut the stub off flush with the floor by sticking the blade in and running the saw zall around the pipe so it cuts flush with the finished floor and a bevel on the inside of the pipe .....glue your flange down and run some tap cons or mushrooms through the screw holes....that is how i have always done pvc closet flanges


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## KillerToiletSpider

Drop closet flange over 4" SVCI baldy sticking out of concrete, yarn oakum into the joint, pour the lead, let it cool a minute, pack lead with an iron, and cut off excess CI with an internal soil snapper.


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## Ron The Plumber

Plastic TKO Flanges

Use extra brass closet tee bolts, attach the tips of the tee bolts with added nuts between the top of the flange and the bottom side of flange, in all the extra holes, just the tips only so the tee's are on the underside of the flange, set flange to your finished grade, when concrete gets poured, concrete will cure around these tee's and gave the flange a secure set.


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## PARA1

KillerToiletSpi said:


> Drop closet flange over 4" SVCI baldy sticking out of concrete, yarn oakum into the joint, pour the lead, let it cool a minute, pack lead with an iron, and cut off excess CI with an internal soil snapper.


Would'nt that melt the PVC?:w00t:


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## PARA1

cleveman said:


> Sharpie,
> 
> I don't want anything protruding up from the slab when I pour. Protrusions will only lead to unevenness.
> 
> Make boxes and put them about 1/4 or 1/2 below the surface. Seal them off.
> 
> Take photos with measurements off the forms.
> 
> Pour concrete.
> 
> Tap around, break out your box.
> 
> Make plumbing connections, fill with sackcrete.


How does this pass the rough inspection prior to pour?


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## cleveman

para,

I don't have any inspections in my area.

I don't even glue the piece coming up from the elbow or tee, but I have a piece of pipe in it just to keep it from filling up with sand.

After I break out and remove the box, then I dig the sand out and glue in the fittings.

If I had to pressure test, I would do it differently. Then I would have to glue and I couldn't cut off the piece below grade, so I'd have to leave it above grade and pour around it and this would create the situation I'm trying to avoid-screeding around a bunch of protrusions.


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## wrenchman

I put a small box around my stub up before the pour, then remove the box after the concrete is set. I make up a flange with bolts protruding to the bottom as Ron mentioned, then cut the pipe lower than the floor to make up for the flange recess, glue the flange in place and fill with around it with sakcrete. Your good to go.


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## Jayson12

If you're working with pvc then stub your w.c. riser above pour and on the rough cut it flush with the floor and glue the correct sized closet collar inside the pipe, for added safety secure it with tapcon screws. If you're working with cast iron I find it is easiest to stub your riser 1/4" below pour (using a lazer transit makes this easy if your away from the wall) and put a foam closet cap over it. Then on the rough lead in a closet collar and secure it with tapcon screws.


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## RopeaGoat

Prior to backfilling I put a dollar plug in the 3" 90 and take a piece of 4", duck butter the inside of one end and the entire outside of the pipe, then slide it over the hub of the 90. When the floor is done the 4" sleeve slides out nice and easy, remove the dollar plug (VERY IMPORTANT STEP) and cut a 3" piece to fit and then put my flange on w/ Tapcons. The 4" gives me enough diameter to fit my hand down and it's small enough to make a nice edge for the flange to sit.
:thumbup:


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## JamesNLA

What is Duck Butter?


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## KillerToiletSpider

JamesNLA said:


> What is Duck Butter?


I'm guessing, but I believe it is the same as soil gasket lube.


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## masterk

Jayson12 said:


> If you're working with pvc then stub your w.c. riser above pour and on the rough cut it flush with the floor and glue the correct sized closet collar inside the pipe, for added safety secure it with tapcon screws. If you're working with cast iron I find it is easiest to stub your riser 1/4" below pour (using a lazer transit makes this easy if your away from the wall) and put a foam closet cap over it. Then on the rough lead in a closet collar and secure it with tapcon screws.


 
When you do a PVC flange like this there is no need for boxes, sleves, cardboard, etc. I use 4" pvc pipe, so that the opening on the inside of the flange does not cause a restriction.


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## neolitic

JamesNLA said:


> What is Duck Butter?





KillerToiletSpi said:


> I'm guessing, but I believe it is the same as soil gasket lube.


If it is,
that's what Grandpa called
"goose grease".
Too bad he died before I got the joke.


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## Jayson12

masterk said:


> When you do a PVC flange like this there is no need for boxes, sleves, cardboard, etc. I use 4" pvc pipe, so that the opening on the inside of the flange does not cause a restriction.


I didn't advise him to using anything of the sort using pvc, I advised him to use a foam collar cap when using cast iron so you have the space to fit the collar on and lead it in, using the foam cap is great because there is no patch work because it is sized perfectly. Also I run my underground pvc water closets in 3" and Charlotte does make a 3" inside closet collar, so no need to over size and no need to sleeve the riser for anything.


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## masterk

Jayson12
Let me clear up my reply. I totaly agree with the way you set a flange, weather it is cast or pvc. I do it the same way. When I said that there is no need to box, sleve, etc. I was trying to let everyone else know that they are doing alot of extra steps to set a flange. The reason I use 4" for the water closet is that the inspectors here don't like the flanges to restrict the opening. I carry 1 type of pvc flange on my truck, fits inside 4" pvc pipe or over 3" pvc pipe.


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## trav007

Thanks for all the good advice. I think one thing is for sure...I'll talk to the concrete crew and see if they care if there is stub out. I also really like the idea of having the flange set at grade with bolts preattached so they set themselves in the floor. Glad to see that there are many creative solutions.


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