High quality logs used in two ways The first use is in a round or flat faced form to support a deck such as in a bridge or wharf The second use is as large end section, heart free, sawn timber suitable for heavy construction Girders for the first use need to be of a durable or treatable species, straight, defect free and have a small end diameter of between 30 and 40 cms depending on the order Girders for the second use generally have similar specifications but need to be larger in diameter (often up to 60 cms) at the small end They can carry a little centre defect depending on the diameter and timber sizes required to be cut