What defect occurs when there is a separation that runs through the timber rings?

The defect that occurs when there is a separation running through the timber rings is a split. A split in timber refers to a major separation along the growth rings that can affect the structural integrity of the wood. This type of defect typically occurs as a result of drying processes or external stresses, leading to cracks that penetrate deeply into the wood fibers, often compromising its strength. Understanding this is crucial for bridge inspections because splits can indicate underlying issues, such as susceptibility to moisture intrusion or further structural failure.

In contrast, a shake refers to a separation that occurs between the growth rings, but it does not penetrate all the way through the timber. Surface checks are superficial defects that occur on the surface of the wood and do not affect the core structure. A check fracture is similar to a split but usually less extensive and often occurs due to stress on the wood, primarily along the surface. Recognizing the differences between these types of defects helps inspectors evaluate the condition of timber elements in bridges accurately.