Half-caps with scarf splice joints, shown schematically in Figure 1, exist in a significant proportion of timber bridges currently in service in WA. However, existing guidelines for calculating the strength capacity of such joints have been found to be considerably over-conservative. This has necessitated the strengthening or replacement of half-caps with scarf joints, even when not showing any signs of distress. As such, at present, there is a need for a more accurate methodology for assessing the strength capacity of scarf splice joints of timber bridge half-caps.