What is the best underlayment for a tile floor? I have read about several types and was wandering if anyone could give me some information on what is the best and will last the longest. I read about Durrock, Hardi backer and some other. I am planning on putting a tile floor down in our new home and have always used Durrock but it is a little harder to work with than some of the new underlayments out and was wandering if the Hardi Backer and other are just as good or not?