In a 5X7 room is 3/4 inch subfloor enough?

It depends. Ceramic or stone?

Hi Bill,

We will be using 12X12 tumbled Ming Green Marble.

Ya know, I had a feeling!! No, 3/4" isn't enough. With stone, you need to add a second layer of atleast 3/8", and preferrably 1/2" before installing the cement board or membrane. As for which is better, fir plywood.

Thanks Bill!

I want to do it right so I appreciate the advice.

Do I have the other layers in the right order? Would the electric heating go under the Ditra?

My heating mat - I forget the name, got it from Costco on line - says the heating mat goes over the membrane (Ditra). I haven't installed it yet so I'd also like to hear the response to that question.

I've heard fervent arguments on both sides. If it's me doing the installation, the mats will go on top.

According the Ditra literature, the heating mat goes under the Ditra underlayment.

Since the last post, has anyone can anyone share there experience with how they installed it and how it is working?