I would like to install a new bathroom floor and have not decided if it will be ceramic tile or natural stone. Although I'm impressed with some floors I have seen of both, my main concerns are longevity and safety. Which do you recommend? The dimensions are fairly clean cut at 9x15. Since the home is older, built in the late 70's, should I strengthen the sub-floor using 3/4 inch thick tiles even though no problems are present?