Hi,
New to the forum. I found it from another forum. I'm looking for information on marble slab installations for bathtub/shower walls. I have a contractor working on my bathroom remodel, but I wanted to check around to make sure everything's done correctly. I figure it's useless to inspect his work if I don't know what's right or wrong.

The marble slabs he recommended are 1/4 inch thick with another 1/4 inch of fiberglass adhered to the back of it. The place I bought it from said it makes it more waterproof, and stronger than natural marble on its own. So far, the walls are open to the studs. What should I be looking for to make sure this is done right? Is the black felt paper necessary? Does he have to install wonder board to adhere the slabs to, or would green or purple drywall work? Would the slabs be adhered with silicone caulk or mortar? Do the wonder board seams have to be sealed with tape and mortar? Does the wonder board need to be adhered to the studs with mortar before screwing them down?

I'm very meticulous about making sure everything is done RIGHT or the best way, and he knows this. However, I don't know very much about this, just what my friend's dad has told me. But, he said things can be done many ways. What methods do you all recommend?

Thank you in advanced for your assistance with this!