I installed a shower pan in my ensuite two years ago. The pan was a solid unit with a 1/2" lip around the edge. I installed it flush with the stud wall and put Hardiebacker 1/2" board on the wall, running it flush with the lip on the pan. This worked great and I was able to install my tiling flush between the Hardiebacker and the shower pan.
I am now installing a shower pan in our kids bathroom. The unit I purchased for them is a fiberglass one from Maax. The instructions say to install the pan flush with the studs and to have backerboard sit flush on the lip of the pan, similar to my install above. My problem this time is that the lip is only 3/16" thick on the Maax pan. I wanted to use the 1/2" Hardiebacker again on the walls, but how do I run it flush with the pan? The only thing I can think of is firring out the wall studs for the pan area only to have the lip sit at 1/2" from the main wall stud. Below is the diagram from the Maax web site. I am planning on using Hardiebacker instead of their recommended drywall. Their diagram doesn't seem to take into account the fact that the flange/lip is only 3/16" thick
Does that make sense? Is there a better way to do this?