1.1 ,This practice has been prepared for use by the designer, specifier, and installer of reflective insulation for use in building construction. The scope is limited to recommendations relative to the use and installation of thermal insulation consisting of one or more surfaces, having an emittance of 0.1 or less such as metallic foil or metallic deposits unmounted or mounted on substrates and facing enclosed air spaces. The reflective insulation covered by this practice must meet the requirements of Specification C1224.