Wood checking is the natural separation that can develop along the grain as large timbers dry and adjust to changes in temperature and humidity. It is a natural characteristic of Mother Nature and is common in heavy timber construction. In most cases, checking is cosmetic rather than structural.
Because large timbers dry from the outside inward, the surface may shrink before the center of the timber. The resulting stress is relieved through checks, which may widen during hot, dry weather and become less noticeable as humidity increases.
Most checking develops during the first season as the timber completes much of its drying process. The progression typically slows significantly after that. Checking is expected in heavy timber and is considered during structural design. It does not mean the wood is defective, rotting, or failing.
Timber package options affect how visible checking is.
Checking is most visible on heavy timber pergolas.
The timber up close in the project gallery shows what normal checking looks like.













