Lenore, who is installing the granite slab shower? Start there and make your priority be hiring a VERY experienced tile professional - one you have vetted carefully to insure that their qualifications meet your design requirements and product selections. Stone slab installations are not for the B team, and especially in a wet area. Can it be done? Yes, depending upon the structure over which a solid surface stone is installed and the methods used. We install solid surface shower walls regularly, but from an empty cavity which we build to meet all specific design and installation specifications, including the pan. A solid stone slab cannot be supported by the pan (it is not meant to support a slab wall). A slab wall is pinned and tied so it is self supported, not supported by a pan. This is a very complex installation. A LOT to consider. As one example, the thickness of your slab? 2cm. 3cm? (effects the weight load on the space). And I could go on. After you have carefully vetted the qualified tile contractor, have this conversation with them. If you question or want to clarify their recommendations, check back or seek professional advice from other qualified sources. Please consult with a professional onsite. Good luck with your project.

It seems like the problem starts at the subfloor. The contractor who fixed the subfloor should have done it in a way so that the subfloor wasn't an inch lower on one side.

We didn't do a tub, but did do a custom neo-angle shower with surround in cultured granite(from a cultured marble vendor). The sequence actually took quite a bit of time: 1) Durock the walls, set the subfloor. 2) CM vendor came in to measure for the showerpan, NOT the surround. 3) 1 week to create the showerpan. They installed it, then measured for the surround. 4) Another week for the surround and inserts, which were then installed. 5) Then, and only then, did the shower glass vendor come out to measure for the glass, which of course took another 2 weeks to install plus a day to dry the silicon caulk. So it was a month after we did the order, until we got to use our new shower! Love it, though - people are sure we've got a Corian shower with matching double integral sink vanity. They have no idea we saved at least 30% using cultured granite.

The guy that did my bathroom tub/shower surround will only use Wedi which is water PROOF not just water resistant It is the only thing he will use. Here is a link that might be useful: Wedi