Wood preservation for preventing biodeterioration of Cross Laminated Timber (CLT) panels assembled in tropical locations

Abstract

Cross Laminated Timber (CLT) is a construction system based on pre-fabricated solid wood panels. As this system is produced with a natural material, its implementation is associated with the adoption of preventive measures against pathological processes intrinsic to wood, such as biodeterioration. This phenomenon can be defined as undesirable changes in wood elements provoked by living organisms that use wood as food supply. Microorganisms, such as fungi, and insects, such as termite and wood-boring beetles are among these organisms. Their developments occur under favorable moisture and temperature circumstances; thus, climate conditions are important factors for the wood structure durability. The use of CLT panels in tropical climates must be associated with wood preservation methods to avoid decay of the structural components. This paper aims to discuss preservation treatment applied to CLT panels in tropical locations, comparing the standards adopted in different countries where CLT buildings are used. Additionally, a case study was conducted. Hence, samples of Pinus sp. from the south region of Brazil and treated with CCB (copper, chromium and boron solution) were tested to identify the penetration and the retention of the preservation product. The tests followed the method suggested by Brazilian standard ABNT NBR 6232:2013. The results showed that it is necessary to establish quality control to avoid CLT production with no adequate wood protection against xylophagous organisms.