When wood cladding degenerates

Abstract

For several decades, the mechanisms of decay of wood exposed outdoor have been scrutinized in order to ameliorate the performances of this versatile material when used for purposes such as house cladding. Performance of cladding seems to be highly depending on durability of wood, in its turn directly connected to water uptake which can vary a lot. How long a cladding can function for is particularly complicated to define also because of its paradoxical role of sacrificial and aesthetic layer. Anyhow, thanks to small reparations and maintenance, many traditional claddings are still preserved. They have been produced and maintained with local resources and show that low-processed wood can be durable in outdoor conditions. The contrast with modern approaches such as wood modification or importation of durable species, lifts the question: what durability of wood is concretely required for cladding purposes? The exhibition shows characteristics of wood weathered for up to hundreds of years, allowing to understand what impact damages can have on cladding’s performance. The samples, issued from traditional French and Scandinavian facades, illustrate how exposure level influences degradation, confirming the role of rot and revealing the one of erosion in degeneration of wood cladding. Both Alder and Pine seem to have the potential to naturally perform well as cladding for longer than it takes for the trees to regenerate. Traditions might teach us how to use local wood in a durable way if we consider biodegradation as an opportunity to build without creating wastes, rather than as a threat.