I've been trying to get this all straight and hoping someone can either verify or correct my assumptions. I keep looking at this stuff and visiting websites. It looks like there are really only two basic underlayments for ceremic tile aside from putting it directly on plywood or other already existing floors. It looks like there is the basic cement/mortar/durock type of board and then there is the den-shield/gypsum type board. Is this correct? Now I read that the gypsum based board has a moisture barrier built into it and is better about keeping moisture out of the foundation, etc. Is this correct? If I do have leakage, where does the moisture go? I also see that there is a difference in gypsum board and den shield in some manner. Does anyone know exactly what this difference is? How tried and true is the gypsum type board compared to the years that cement tile board had been used? I don't want to end up like the people with the NEW stucco revolution and have dry rot in a year.
What about the cost of durock vs cement vs den sheild etc? Am I so far off in my thinking that I need to be thumped? Can someone help?