I would like to insulate the floor/ceiling space of a house and basement addition. The addition extended a room on the first level and a foundation area was created beneath it. A wall was knocked out between the original foundation and this new room in the basement and a door put in. The room addition always has a cold floor and my brother says we can insulate it, but he is not available to help me with it and can’t tell me which insulation is best for the job.

Can I use expanded polystyrene, reflective insulation, r-19 denim, r13 fiberglass foil faced, r19 mineral wool, unfaced fiberglass, etc? Which would be best?