A composite sheet material includes, in an exemplary embodiment a porous core that includes at least one thermoplastic material and from about 20 weight percent to about 80 weight percent of natural fibers based on a total weight of the porous core. The natural fibers include at least one of kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulosic fibers, sisal fibers, and coir fibers.