Fire retardant treated wood products – Properties and uses

Wood is combustible, but can still perform very well in fire, especially for load bearing structures. However, visible wood surface may not fulfil the fire requirements in building codes and fire retardant treatments may be an option. The highest reaction to fire classification for combustible products may then be reached. However, the excellent fire performance of the virgin fire retardant treated, FRT, wood products may degrade over time, especially in outdoor applications. Two cases of long term durability of FRT wood products exist and standard procedures are available for limited hygroscopicity and maintained fire performance after weathering. Structural degradation may also occur, but is relevant only for load-bearing uses. Recommendations on end uses and suggestions for further research are included.