Moisture Content of Wood

The moisture content level within timber ultimately dictates the subsequent movement and potential distortion when in service. Where your timber item is to be used affects the amount of movement and what happens to the wood. This handy infographic indicates the recommended moisture content for joinery and timber products used inside and outside of buildings in the UK.

Please note that for external timber exposed completely (such as in gardens, landscaping, car ports and other exterior structures) the moisture levels can be considerably higher or lower in summer. Consideration to the time of year of any given installation is needed, as the timber will affectively acclimatise to its environment. Window Beading Wood

The above is a guide only and more, in depth research and analysis, of the specific environment, temperature and humidity is recommended when planning the use of timber items in (or outside) of buildings. Hardwood Glazing Bead Profiles

Equilibrium Moisture Content of Wood

The moisture content of wood depends on the relative humidity and temperature of the air surrounding it. If wood remains long enough in air where the relative humidity and temperature remain constant, the moisture content will also become constant at a value known as the equilibrium moisture content (EMC). Thus, every combination of relative humidity and temperature has an associated EMC value. The EMC increases with increasing relative humidity and with decreasing temperature.