I am replacing a small tub with a custom-built tile shower and I am having a slope issue. I know most people shoot for 1/4 in/ft floor slope. Some people say 1/4 to 1/2 in/ft slope. Some say you can go as low as 1/8 inch/ft especially if it's for an elderly person, as in my case.

If you look at the sketch below, you will notice that if I aim for a 1/4 in/ft slope along the longest floor length (drain to far corner) I end up with almost 3/4 in/ft slope along the shortest floor length (which happens to be where someone steps into and out of the shower and may possibly slip). In addition the steep slope may be uncomfortable to stand on.

I could reduce the slope along the longest floor length to 3/16 in/ft (by screeding my preslope mortar bed to a mark 1/2 inch up the wall instead of 3/4 inch). That would reduce the slope along the shortest floor length to 1/2 in/ft. Is that a better option, or am I inviting drainage problems?

[i93.photobucket.com]

Depending on where the vent is connected to the drain. You don t want too much slope before the vent because you could drop below the the trap weir.



Edited 1 times.

Your photos are not the most easily understood items. Unless you put the drain in the center of the shower the "short side" will ALWAYS have a steeper slope.

why is that? i would just make less slope on the short side. the water will still run to the drain, it will just overflow sooner than the long side if the drain backs up

- - - - - - -

PLUMBERS "Protecting The Health Of The Nation"

laying sloped/pitched mortar is an art form in and of itself - hence the trade of masonry

simply aim for 1/8 per ft long side and 1/4 per foot short side

the two 'pitches' will 'blend' and merge


.... like I said, an art form


ps. at 1/4 per foot over 15" you will have 5/16" total to 'step down' assuming door is on long side

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Codes say floor slope must be 1/4 to 1/2 inch per foot. But people say you must have a straight screed line along your perimeter walls so your tiles will fit nice.

As my sketch shows, if you shoot for 1/4 inch/foot slope to the farthest corner, your slope will be 3/4 inch/foot to the nearest wall. Yeah, you could lower the mortar bed at that point to reduce the slope, but then your tiles would need to be tapered. Some people say tapered tiles look ugly and make for more work.

So, I have a dilemma. Not sure which is more important. Keep slope under 1/2 inch/foot or keep screed straight.