proper degree of tile floor slope to bathroom floor waste drains

[MasterPlumbersKeymaster]

am involved in current complete bathroom renovation. Have been tod by other professionals that bathroom floors do not slope sufficiently toward bathroom floor waste drain. Can anyone tell me what the slope shoud be and/or where to find that info, ie, reference code or other document.

Thanks AmAsia

[nicktheplumberParticipant]

I am surprised that you are installing a floor drain in a residential bathroom. Such drains are not required in any residential bathrooms in the USA. They are required in commercial installations used by the public (presumably because you may need to hose down the bathroom floor).

The only “floor drain” installed in most residential bathrooms is the drain in a shower stall. The UPC and IRC specify a slope of at least 1/4″ per foot but not more than 1/2″ per foot. You could use those dimensions in designing a floor drain in your residential bath, though I don’t know why anyone would want such a drain in his bathroom…

NtP

[Robert Stephen MortonParticipant]

Nick. You should not be surprised by a floor waste in the bathroom. In Australia we have lots of showers & we often step out onto ther floor wet. The water that drips off must go somewhere, hence a floor waste.
We may put in a dry floor waste that discharges to the outside of the building in a position that will not cause nuisance & terminating with a frog flap to keep out vermin.
Alternativly we can put in a wet floor waste. A “P” trap in the floor with a bathroom fixture discharging to it so that it is kept charged.
The problem is that our regs state that a fixture that discharges to a wet floor waste does not need traping provided it is within 1.2m or 4 ft.
this untrapped lenght of pipe grows bacteria on the walls of the pipe & after a while it pongs.
Best way to fix it is to trap the waste.& still discharge the waste above the seal of the floor waste.
Bob

[nicktheplumberParticipant]

I thank Bob for his comments about Australian bathrooms. Having a floor drain makes sense if there are shower stalls with people stepping out of the dripping wet. This does not seem to be an issue for US residential bathrooms, where most showers are part of a bathtub arrangement. But in other institutional situations, such as in US military barracks, prisons, and universities (no moral equivalence implied!) floor drains are generally installed outside of the actual shower areas. I haven’t installed any of these plumbing setups, but I’ve had experience as a user in two of the three…

NtP (and, no, I’ve never been convicted of any crimes).

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