Setting a closet flange

[Mandrake]

Roughing in plumbing for a new bathroom. I'll be building a subfloor about 1' over concrete slab. I have 2 questions regarding setting the toilet's closet flange.

Do you set the flange so that its face is planar with the floor, or proud of the floor? If proud, by how much?

I've found two types of available flanges. The first solvent welds outside the pipe, like any common pvc fittings. The second fits inside the pipe. It would reduce the available diameter, but also pretty much ensures nothing would ever seep out a bad weld joint. Wondering what folks opinions are on picking one.

[woodworker2000]

I'm no expert but I would much prefer the certainty of the inside flange joint over the uncertainty of the joint on the outside flange. As they say.......poop don't flow uphill.

[chips ahoy]

I just finished my bathroom, set the flange flush to the finished floor and 12" to the center off the finished wall, 12 1/2" if the wall is unfinished.

Mel

[Mr_Mike]

Sits on top of the subfloor.

It doesn't really matter if you use an inside or outside fitting. My preference is one with an integral street Ell, but really, any one will do.

[blackhat]

External and flush with finished floor too minus 1/8th".

[Alex Grigoriev]

The toilet's outlet hole is not big anyway, and outside v inside flange will not make difference at all.

[blackhat]

That would be incorrect.

[Alex Grigoriev]

blackhat said:

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That would be incorrect.

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The outlet is about 2 1/2". The flange hole will be 4" or 3 1/2".

[Mandrake]

My line size is 4". My original attraction to the internal flange was due to the concrete and tar schmutz that coats the outside of the pipe from the slab pour. Since I am now planning on building up a subfloor, I can clean and cut the pipe and couple a new section if I need to; but that sill might have me glue / welding to a previously schmutzed surface.

[blackhat]

PVC primer and a rag on a stick should take care of the schmutz.