Traditional natural wood treatment methods are regaining prominence in the modern timber industry, driven by trends towards sustainability and a reduction in the use of chemical preservatives. Among these, the Japanese technique of yakisugi (or shou sugi ban) stands out, using fire and natural oils to enhance the wood’s resistance to weathering and improve its aesthetic appearance. This study examines the fire response of charred spruce wood and the influence of additional treatment with tung oil, as scientific data on this method remain limited in the literature. The research was based on a comparison of untreated, solely charred, oiled, and brushed samples. The results showed that charring the wood provides a comparable fire response to that of untreated wood, thereby confirming the first working hypothesis. In small flame tests, ignition occurred only in systems that had been previously oiled, whereas charred-only wood demonstrated good stability. Analysis of mass loss and oil uptake revealed differences between differently prepared surfaces, with the combination of charring and brushing affecting oil absorption characteristics. The second hypothesis was also confirmed, as brushing the charred wood surface did not significantly affect mass loss during fire exposure. The findings confirm that charring represents an effective and environmentally friendly alternative for the treatment of façade cladding, maintaining visual quality and providing adequate fire safety.
|
