Project Barn Q6:

Went to Lowes and Home Depot to look into the foam board that I would put down over the vapor barrier and under the concrete. I was confused because the blue, white, grey and metalized foam insulated boards all said "wall", and none said foundation. I asked the staff (7 construction and hardware experts on break), and got a blank look. They never heard of insulating a pad.

Question 6:
could some one provide the precise brand of the under-foundation insulation board so I can get started?