Subfloor for Garage Reno | Terry Love Plumbing Advice & Remodel DIY & Professional Forum

Good morning everyone. I am converting the small garage of my 1930s house into an office. Garage sits on 6 inch concrete slab, feels a little damp after rain. Planning to lay ceramic tile over a subfloor get some warmth and moisture protection. For subfloor, I bought Delta-FL product. Two questions:

1. Any experience using Delta-FL in this sort of application? Recommended?
2. What to put over the Delta-FL? OSB vs Wonderboard?

Thank you for your help!
--Paul