I know that a shower floor needs to slope 1/4" - 1', but when installing a large shower 4' x 7' do I set the float strips at 7 x 1/4" = 1 /3/4" + 3/8 and accept the larger slope on the shorter dimension. Also, if I'm using larger 8 x 8 tiles is there any concerns with the slope.
How are you going to bend the large demesioned tile to fit the curve of the slope? You will end up cutting the 8 x 8's to fit correctly and it will look pretty unprofessional. I rarily if ever use tile larger than 2 x 2 for shower floors and never over 3 x 3. I strongly suggest you reconsider using the 8 x 8.
Based on these responses, the bathrooms that I have seen using larger tile must have little or no slope to get the tile to lay flat. So can I use 4 x 4 or do I have to use Darrel's suggestion of 3 x 3 or less.
as MB says your perimeter needs to be level. With the perimeter level you would have a "Steeper" slope parallel with the longer wall. Unless the drain is exactly the same distance from all the walls,curbs you will have a different pitch on every side.A wood float with the corners rounded off(like a pool floaters trowel) would help "shape" the mud and give you a nice flow . 4x4 would be the max.imum size I would lay without causing serious lippage. If your using small grout joint say 1/16 or 1/8 lippage could be a problem, a 3/16 should cure that. If your tiles have rounded edges that would help even more.
I am removing a bathtub, 30 years old, and replacing it with a ceramic tile shower. The shower bed will be 31" x 60". The drain is centered. That means that across the 15"@center I would have only 3/8" slope? Then across the longer side, 30", I would have 5/8"?
Also, looking at Michael Byrnes' article on "Morter Bed Shower Floors", I am putting this shower on an existing concrete slab floor. What parts of the layering can be skipped or altered for slab applications? I am useing a waterproof wallboard. Should I also use the cement backer board? Thanks, Tim