An underlayment that meets underlayment requirements and provides thermal insulation is disclosed. The underlayment includes a core material and an upper emittance layer having an exterior surface. An upper reinforcement layer is positioned between the upper emittance layer and the core material. A first encapsulation layer is positioned between the upper emittance layer and the upper reinforcement layer. A second encapsulation layer is positioned between the upper reinforcement layer and the core material. The underlayment includes a lower emittance layer having an exterior surface. A lower reinforcement layer is positioned between the lower emittance layer and the core material. A third encapsulation layer is positioned between the lower emittance layer and the lower reinforcement layer. A fourth encapsulation layer is positioned between the lower reinforcement layer and the core material.