I have a newly built (seven months) shower and during the construction the tile installer applied a paint on membrane over the mortar bed of the shower pan along with the walls just ahead of laying tile. A PVC type liner had already been installed over the pre-slope and flood tested for 24 hours. The drain assembly has the plastic ring style weep holes from the noble company. When I saw it at the time of install it seemed like a thorough detail that would make the shower more water tight. However, working on a second bathroom I ran across commentary about this very situation and the possibility of creating a mold problem. What are the telltale signs of a problem? Would it be advisable to remove the tile from the floor of the shower and scrape off the membrane? I am certain that the shower is constructed to a high standard in all other respects. I have recently noticed faint odor in that bathroom which seems to be coming from the drain but have no idea if that is an indication of mold.