Sagging bench

Can Wood Plastic Composites (WPC) be used in other areas (beyond decks)? The answer is complex and answer depends on the load, type of structure, safety/risk assessment, composite materials used, manufacturing technique, tensile strength, etc.

Often, WPC should NOT be used. See image to the left for a bench that needs a 2×4 support under the sagging WPC bench.

“WPC products are emerging for more demanding structural applications, beyond residential deck boards and guardrails….Implications for design are that WPCs appear viable for applications that require durability and high bearing and bending strengths. The high shear and dowel bearing capacities of WPCs are advantageous in connection design. Current commercial WPCs are less suited for applications controlled by beam or column stability (buckling), due to their relatively low modulus of elasticity and tendency to creep.”

Excerpt from “Wood Plastic Composites: Structural Design and Applications” By Donald A. Bender, P.E., Michael P. Wolcott, J. Daniel Dolan, P.E. 2007. STRUCTUREmag. http://www.structuremag.org/article.aspx?articleID=450

Have you used WPC products on a non-typical project? Write a comment about your experiences.

Other resources

Durability of wood-plastic composites Morrell, J.J.; Stark, Nicole M.; Pendleton, David E.; McDonald, Armando G. 2010. http://www.treesearch.fs.fed.us/pubs/36632

Wood-Plastics Composites Done Right. By Kirk Hanawalt, Plastics Technology. May 2012. http://www.ptonline.com/articles/wood-plastics-composites-done-right

Composites as High Performance Building Solutions http://www.greenbuildingsolutions.org/Main-Menu/Home/Modern-Materials-Archive/Reduce-Reuse-Recycle/Composites-as-High-Performance-Building-Solutions.html

Wood-plastic composite. Includes Advantages and disadvantages. http://en.wikipedia.org/wiki/Wood-plastic_composite

Trex Strength Vs. Wood By Richard Rowe, eHow Contributor http://www.ehow.com/facts_5682759_trex-strength-vs_-wood.html