An underlayment product comprises a fibrous mat having an upper surface and a lower surface. A rubberized asphalt coating is applied to the lower surface of the fibrous mat and extends at least partially into the fibrous mat. An oxidized asphalt coating is applied to the upper and lower surfaces of the fibrous mat generally encapsulating the fibrous mat including the rubberized asphalt coating provided on the lower surface of the fibrous mat. The oxidized asphalt layers may be coated with a release layer such as talc, granules or a polymer.