(See definition in Air Conditioning section) The higher the R value, the greater resistance to the flow of heat. R value requirements for walls and floors is R-11 insulation; for ceilings R-19 but when insulating an attic, in order to conform more often to State Energy requirements, R-30 should be used. R-11 used for floors, R-1 9 walls may be constructed by installing wall sheathing on the outside of 2x6 studs with R-11 between the studs.