I'm building a sauna and bathroom in our basement. I'll have to raise the floor to allow for plumbing, and it will drain into a Saniflo pump to pump it up into our drain line (we didn't have plumbing installed when our home was built).

I need advice for raising the floor of the sauna/shower area. My plan was to use 2x8s vertically, with cement board on top, then Ditra, then tile. How far should I space the 2x8s? And any other advice/tips for creating a solid raised floor?

I'll have the sauna drain unite with the shower drain and then run into the Saniflo pump.

Thanks.