I am a tile guy in your forum. I pose this question because I was wondering which trade should install the pan liner for a tile shower floor. The tile handbook recommends a "Pre-slope" under the liner and weep holes free and clear. I have been on jobs where the plumber installed the vinyl liner flat on the subfloor, nails it to the studs and then clamps it into the clamping ring of the drain. He feels he is done. If the tile man puts in a mudd base over the liner without adjusting it for a pre-slope the water that goes throught the deck mudd ( as it is supposed to) gets trapped. So, I ask again. Who puts in the shower pan liner in your area?