You need to get the foam vents. They are kinda u shaped, slightly less narrow than the joist bay. Staple them to the bottom of the plywood then add your insulation. It doesn't look like you have enough room for r30, so in your case go with the r19, or the highest r value you can get for the depth you have. Pretty sure you can get all the stuff from HD. Then you can put your ceiling right on the bottom of the rafters. It would be ideal if you had a vented soffit and a ridge vent on the top of the roof as well to allow positive airflow, even if you dont still add the foam vents, the outside stuff can be changed at a later date. Reason I asked about the heater, my brother had one in his shop in MD and when he moved to Canada he put in a gas radiant heater. He said the radiant worked so much nicer. That is what im planning on putting in mine.
|