Homeowner Forum / Construction / December 2005

I think I need something verified. Our master bath shower is leaking.
Obviously a bad pan install. The water leaks out under the marble sill.
They cut open the 1st floor ceiling to have a look at the drain to see
if it was leaking around it and the vinyl liner. It's bone dry. I am
inclined to think that the water is getting between the liner and the
mud base and wicking its way towards the marble sill and up. Another
possibility is the a coller or sleave extension where the drain
attaches has a crack. Reguardless of all this I would think that water
that got on top of the liner would still move down towards the drain. I
did some research and saw that it's typical to pre-slope the floor (on
top of the plywood subfloor) with a mud base then put down the liner,
then make the real mud base for the tile. Most site I've been to say
it's done incase water get in between the liner and mud base.

Well from what I can tell my shower has no pre-slope mudbase. If you
look at the photo, the liner (grey)looks to be resting on the subfloor.
I also remember the plumber putting down the liner on the subfloor. The
mud base and tile was NOT done by the plumber but by the tile guy. I
would think the tile guy would have noticied this. Is NOT haveing a
pre-slope still an acceptable way of do a shower ?????

https://home.comcast.net/~thomas9780/showerpan.JPG