Influence of natural weathering on the ignition and relative burning rate of selected softwoods

In recent decades, coniferous façade boards from untreated wood have been used extensively without the use of biocides, flame retardants and weather protection coating systems. This work is focused on testing selected properties 4 softwoods - spruce, larch, pine Douglas fir exposed outdoors for 3, 6, 12 24 months during direct exposure. When to outdoor conditions, all species significantly changed colour grey shades, while highest roughness changes were observed in spruce. FTIR analyses confirmed a significant decrease lignin surface layers due weathering. After weathering, these measured characteristics had no effect ignition relative burning rate tested wood. The tests higher compared density influence, wherein mass losses fir, spruce larch. According results work, wooden façades treatment do not change long-term exposure whereas impact.