Reconstituted materials are more dense and offer increased longevity. Fingerjointed material consists of using shorter pieces of wood glued together to make a longer piece. This technology makes use of wood that could previously be considered waste. Recycled-content materials include substances that are salvaged from the waste stream such as sawdust and paper. Tropical hardwood refers to wood harvested from the tropical forests that are being harvested in a destructive manner.
Recycled trim refers to the reuse of trim salvaged from building demolition.
The increased density of the materials resists cracking and other deterioration. Fiber-cement materials, for example, offer very long warranties and have zero flamespread. Steel and aluminum siding materials are predominantly fabricated from recycled material. Although the embodied energy is high when the materials are originally made, they require much less energy in a recycled form. They can also be recycled again after use in a building.