I am currently remodeling my bathroom. I decided after buying a fiberglass pan, that i wanted to go more formal and do a full tile shower. I have already reun my drain and now need to get the pvc liner pan. my only question is when i run the pvc liner up the side walls. I have to run my tile backer down over it. how do you fasten the tile backer where it overlaps the pvc liner. Do you just screw through it or what. i dont know if pvc liner will seal itself around screw or what. Are there any tile layers that might be able to help? I would greatly appreciate it.