Moisture in timber

One of the most important factors affecting the performance and properties of wood is its moisture content. The amount of water present in wood can affect its weight, strength, workability, susceptibility to biological attack and dimensional stability in a particular end use.

We estimate that over 80% of the in-service problems associated with wood are in some way related to its moisture content. The importance of the interaction between water and wood cannot be understated and, if not properly understood and taken into consideration, can result in the need for expensive remedial measures.

This Wood Information Sheet provides basic information for the specifier and user on the facts and importance of the moisture content of wood. It considers drying, shrinkage and movement, including movement values for some common species, and also looks at measuring moisture content, particularly the use of moisture meters.


Contents:

• Water and wood
• Reasons for drying timber
• Principles of timber drying
• Measuring moisture content
• Specifying moisture content
• Care of dried timber

This Wood Information Sheet was revised in June 2016. The graph in Figure 3 was updated and the section on shrinkage was amended to reflect the changes. A moisture content control plan was also added in the specifying moisture content section.

This Wood Information Sheet was reviewed in February 2017 and minor corrections were made to the references section.