Keep Timber Dry Where possible protect timber under a roof, or with a good quality seal. Provide detailing that does not trap moisture (particularly important for connections), and which allows rain to runoff and not sit on top of timber. It is particularly important to protect the end grain of timber from moisture. Protect Timber from Sun Shading timber from the hot sun will minimise cracking due to constant shrinkage and expansion as the dries rapidly at high temperatures. Where paint is used, a light colour will give lower wood temperatures and hence enhance durability. Isolate Timber from Pests Barriers should be installed so that insects that eat wood cannot gain access to the timber in the building. Chemical or physical barriers under buildings mean that any subterranean pests such as termites must enter the building in a way that can be seen in the regular termite inspections and be removed before they have had a chance to inflict damage on the structure. All barriers require careful planning at the design stage, diligence and attention to detail during construction, and due care during maintenance of the building. Chemical Preservative Treatments A range of different chemical treatments has been developed to enhance the durability of timber considering the action of weathering, fungi, insect pests or fire. Chemical treatment can significantly increase the lifetime of timber components, and thus may be a cost-effective durability strategy. Even treated timber should be protected against sun and moisture if possible. Protect Timber from Fire Fire ratings are given in the BCA for different classes of buildings. In many cases, these can be achieved and exceeded by timber construction using protection of members with good insulators, or intumescent finishes, use of oversized members that can accommodate some loss of section in a fire, or use of chemical impregnation that reduces timber’s flammability. Maintenance Maintenance of any building material is vital in order to achieve satisfactory performance in the longer term. The unique character of timber can serve its purpose for many years provided protective coatings and treatments receive the required maintenance. |