Insulation seasonal room

I have a outside deck that I recently enclosed. The deck has a fiberglass surface, which is now my roof ceiling. I poured a concrete floor and installed radiant tubing to attach to existing home system.
How should I insulate? Do I need to install baffles in ceiling, before insulating, or can do without. My house is spray foam and no baffles were used. I am not doing spray because to small for contractors to come out.
Any ideas