When examining a piece of lumber, you may notice cracks running along the grain. These cracks can be classified into three types: checks, splits, and shakes. Understanding the differences between these defects can help woodworkers and engineers to determine whether a piece of lumber is suitable for use in a particular application. By learning about the characteristics of each defect, you can make informed decisions about which pieces of lumber to use in your projects and which to discard.

Checks are shallow cracks that develop on the surface of the lumber during the drying process. The outer layers of the lumber dry faster than the interior of the lumber, leading to tension within the wood. These cracks tend to develop along the growth rings of the tree but rarely reach deep into the lumber.

Splits are more severe cracks that run through the whole length of the lumber, from one surface to the other. These cracks often develop as a result of drying cracks or physical impacts upon the lumber.

Shakes, also known as fissures, are cracks that develop within the living tree itself. There are two types of shakes: ring shakes, which develop parallel to the growth rings of the tree, and star shakes, which develop from the centre of the tree outward. Both of these types of shakes develop due to environmental factors, such as freezing temperatures, strong winds, or infections by bacteria. For advice from Timber Merchants Southampton, visit https://www.timbco.co.uk/

When selecting a type of lumber for a specific application, it is necessary to understand which types of defects are harmful to the lumber’s use in that application. For instance, in applications that require large amounts of structural strength, such as heavy framing of buildings, only checks pose a threat to the structural integrity of the building. However, in applications that require finer woodworking, such as cabinetry or fine joinery, both splits and shakes can be problematic for the structure of the build.

Also, in applications that require the lumber to withstand heavy environmental impacts, such as outdoor landscaping, only splits pose an important threat to the structure of the outdoor installation. In these cases, understanding the differences between these types of defects can enable you to make informed decisions about which types of lumber to use in your projects and which to discard fully.