a polymer and wood composite structural members can be manufactured by extruding and injection molding a composition comprising polyvinyl chloride , wood fiber and optionally a concentration of an intentionally added waste stream . such structural members have strength , workability , fastener retention , resistance to rot and insect attack , and thermal properties sufficient to constitute an advanced composite wood replacement material . the advanced structural member can be used as a component in construction of any structure requiring sized lumber or specifically shaped wood products . in such an application , the structural members can be extruded in the shape of commonly available lumber . the structural members of the invention can also be extruded in complex shapes adapted to the assembly of windows and doors used in both residential and commercial structures . the structural members have a modulus , a coefficient of thermal expansion , a coefficient of elasticity , a compressive strength and other related properties ideal for use as a replacement for either metal or wood , window or door structural components . the preferred structural member is manufactured from a polyvinyl chloride and wood fiber composite that optionally contains an intentionally recycled impurity component . such components comprise waste materials common in the manufacture of wood doors and windows . we have found that the cooperation between the amount of polymer material , the amount of an oriented wood fiber , and control over water content results in the improved structural properties of the composite structural members of the invention .