I am doing a bathroom remodeling. My contractor uses Durock cement board Next Gen around the tub. We plan to have tiles (12" x 24") installed around the tub. My contractor assured me over and over that I don't need to use membrane. He said he has done it for 10 years. There has never been any problem. But I've done some internet search. Many websites seem to suggest that membrane should be used, especially around the shower area. Not sure if I should insist that he uses membrane. Any advice?