We live in an earth contact home. I want to put linoleum on the floors, but do not want the coldness that comes with linoleum on concrete. The floor has to be leveled. Is there any insulation to put down before the linoleum to make the floors warmer in the winter? We don't want to add more than 1/2 inch, my problem is similar to the one asked in this discussion and the store people didn't give much hope. Is there any?