Which timbers are suitable for indoors and outdoors?

Any species of timber is suitable indoors. Difficulty usually arises when an indoor species is installed outdoors. Class 1 timbers, such as Ironbark, can be used in or on the ground and will last a minimum of 50 years. Class 2 durability timbers, such as Spotted Gum, will last 25 to 50 years. Classed 3 and 4 timbers can be successfully used outside above ground, so long as an adequate coating of oil is applied and maintenance is carried out regularly. See our species page for more information.