How high should a toilet floor flange be set above basement floor slab?

Question

In the process of finishing a basement bathroom. Rough-in is provided for all fixtures. At what height should the floor flange be set? I plan to use some type of floor tile.

Answer 1

Good building practice is to have the floor flange even, or slightly above the finished floor. Ensure that you fasten the floor flange to the floor and not just count on the ABS adhesive to support the toilet or you'll be asking for trouble.

Setting the flange any lower will provide an opportunity for leaks. Doubling the wax ring is poor construction practice.

Answer 2

In this part of the US we call the flange a closet collar. lol
Yes the collar can be right on top of the concrete, or it is not a problem to go right on top of the tile. Too low, can cause leaking too high, and the toilet will be off the floor and could break.
Usually 12" center of the finish wall. One other note, put plumbers putty on the surface of the toilet touching the floor.
Will cushion and also protect your throne while you are tightening the bolts

Answer 3

The floor flange can be set directly on level finished concrete.
Bronze or plastic flanges are approx 1/2" thick at the rim. & should still allow rim to be above the thickness of the tile & thinset.
Not a problem if tile goes down first.

Answer 4

Toilet flange should be set flush with the top of concrete. Tile the floor before you set the toilet. Using a wax ring with plastic horn (funnel shape) set the toilet last.

Answer 5

You pretty much want it to be flush with the finished floor. A little higher is ok. But lower is even better. If it ends up being too low... just use 2 wax rings.

Answer 6

Even With Floor.