Question: So, the shower pan mfg suggested that the backer installs up to the small ledge of the pan which is about 1/4" thick and 1 1/2" high. He mentioned it will not fit flush and the backer board will protrude out leaving about 1/4" delta from the surface of the pan lip and the surface of the backer board. He also mentioned that when tiling, the tile will then come all the way down to the top surface of the pan, even thought there will be 1 1/2" of dead space due to the shower lip and backer board mismatch as I stated above. Assuming this approach is correct, I had planned on adding silicone where the two come together to make sure it's sealed. Does all this sound correct for this type of install? I'm not comfortable with the 1 1/2" (1/4" deep) of dead space. Thanks.