Natural durability and treatment considerations Timber is a variable material; different species have different properties. Some timbers, typically many hardwoods, are more naturally durable and more resistant to decay, fungal or insect attack. However, some softwoods contain natural chemicals that can also make them more resistant.
Because softwoods are inexpensive, readily available and renewable, they are popular for general construction work. Depending on where they are needed in a building, some will require additional protection by using a preservative treatment.