A structural laminate comprises at least one planar facing sheet with a rigid foam attached to one surface of the facing sheet. The rigid foam is characterized in that the major recurring chemical linkage therein is the isocyanurate moiety. Distributed substantially evenly throughout the foam is a mat of long straight glass fibers arranged in layers substantially parallel to the facing sheet. The process for producing this structural laminate comprises the steps of contacting a thin, substantially incompressible yet expansible mat of long straight glass fibers with a foam-forming mixture of an organic polyisocyanate and a diol, positioning a facing sheet on each face of the mat, and passing the facing sheets having the mat and the foam-forming mixture there between through the nip of two rotating rolls.