Ditra membrane worth the money?
Hello. My contractor quoted me an additional $1100 to use Ditra membrane under the 400 sq ft of porcelain tile he will lay over the cement floor in our walk-out basement. He says it is a good product, but optional. I've seen it on TV and read a bit about it (which makes me want it, of course) but I'm concerned about the cost. Our existing cement floor is level so far as I can tell.
What do you think, is Ditra worth the money? Does your answer change if we install slate rather than porcelain?