Standard-compliant development of a design value for wood–plastic composite cladding: An application-oriented perspective

Abstract

Bio-based materials, such as wood–plastic composites (WPC), have gained the interest of the resource-intensive building industry. Presently, this novel composite is being used in decking and cladding. The structural design of façades made from WPC compounds, however, has been difficult in the past due to a lack of design principles and experience.

In this case study a design concept is developed, which combines material attributes describing the strength loss of the material due to different weathering processes on façades. Although this approach is widely used for approvals of cladding kits in Central Europe, it has not yet been used for WPCs. This paper is unique because for the first time research findings taken from a literature review on WPC attributes are used to obtain a realistic WPC design value for engineered façades. Simulations of WPC aging in three main categories predicted a strength loss of approximately 50% compared to the virgin material. Nevertheless, a WPC material design value which includes the effects of material aging is still useful for a façade planner’s practical work in view of the mandatory codes and standards in this field.