Which Timber to Use
Both seasoned and unseasoned hardwood can be used for truss fabrication. Even so, size availability may limit the use of large solid sections, and create the need to use multiple smaller sections, instead.

Table 1 (seasoned hardwood) and Table 2 (unseasoned hardwood) give an idea of cross sectional sizes, lengths and stress grades available. In reading these tables it is notable that seasoned timbers tend to offer higher grades; but unseasoned timbers tend to offer slightly longer lengths.

In addition to solid timber members, engineered timber products can also be used for truss fabrication. These include nail plated hardwood and glue laminated hardwood.

• Nail plated hardwood utilises kiln dried solid timber that is combined together to form longer and/or deeper members by virtue of metal plates connecting pieces together. These are generally available in all species of hardwoods, but care should be taken to ensure the nail plates are suitable for the intended appearance requirements. In addition, nail plated hardwoods, are not recommended for use where directly exposed to external environments.
  
• Glue laminated hardwood (Glulam) utilises small strips of timber which are glued together. A key benefit of this product is the capacity to create curved elements and to remove many natural imperfections in the timber. It is generally available in Tasmanian Oak, Spotted Gum, mixed hardwoods and Cypress. There is also a limited supply of Brushbox and hybrid beams utilising hardwood flanges and softwood webs. Check with suppliers for sizes and strength specifications as these vary for each manufacturer.