I'm rehabing a bathroom. In the process of putting down plywood, then on top of that I intend to put Hardibacker and then the ceramic tile. I pulled out the old tub and am doing that part of the floor along with the rest. I intend to put in a Sterling 30 X 60" shower receptor (model # 72141120). My question is, should I tile the whole floor, then install the shower receptor, or can I put the Hardibacker down, then put some thinset down and install the shower receptor on that, then tile the floor up to the shower receptor. Or, perhaps there is another way you could recommend.
You don't need to tile the whole floor nor do you need the hardibacker under the shower pan. You do need to verify the floor is sturdy enough for a tile installation. This includes the joist structure and the subfloor. You mentioned adding ply, this is normally good. What type, and how? Also, make sure to follow the instructions on the hardi...it needs to be bedded in thinset and screwed or nailed down per the specs, then (you can do this while tiling) you must use the alkali resistant reinforcement tape on the seams.
A good resource to check out things for tiling is www.johnbridge.com. There is a deflection calculator available in the forum that will verify your joists are sufficient. No sense in doing all that work and have it fail. Note, from what I read, the simple failure of not using thinset under the cbu often doesn't show up for as much as 10-years. Not taping the joints maybe a year or two.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013