I have found several references for 1 4 in per 12 in run.
Minimum slope shower floor.
Shower floor slope to efficiently drain the recommended minimum slope for a shower floor is about 4 percent or a 1 2 inch drop per every 12 inches from the shower walls to the drain.
It can be done but several steps must be taken to prevent water from going all the way to the sub flooring but to answer your question and i ve been doing it for 20 years the slope is a minimum of 1 4 per lineal foot i slope it a bit more depending on the shower size and how far it is to the drain.
Wheel chair entry requires a larger shower opening a minimum of 60 inches with a shower width of at least 30 inches.
This would be very much like a handicapped shower in its design a bit different but similar.
These stall should have no curb to allow the individual to roll into the.
Thresholds should to be slanted inward at a 5 degree 1 4 pitch or slope so water flows toward the drain.
Land on the sloped curb and shed towards the drain and not onto your bathroom floor.
The recommended slope for flat roofs is usually 1 1 8 inch per foot or 2 1 4 inch per foot according to the professional handbook of building construction published by john wiley sons new york.
We could find no reference to recommended slopes when trench drains are used in a floor.
Proper slope on shower threshold.
So if we make the pre slope 3 4 thick at the drain it needs to be a total of 1 1 2 inch thick at all your walls.
I asked for the minimum slope and it looks like it is sloped 1 and 1 4 inch for 22 inches from left to right.
My contractor has just ripped out my shower floor because it was very uneven.
So mark a line 1 1 2 from the floor all the way around the wall studs.