How dry should the wood be to build furniture

This is an area where you will get many different answers. The reason is that there is no single true answer, only guidelines. Another reason is that there are people living by selling wood, who then will provide different answers based on what they have to sell. The major reason for the different answers is that there are a lot of dependencies:

• The history for the dryness of wood is an important part of the answer (and you will not likely get to know the history unless you are talking expensive wood)
• The current air humidity and the last months of air humidity
• The thickness of the wood
• The type of wood
• What level of air humidity that is normal where you live
• What you are going to use it for.

General about wood moisture content

Common recommendations about wood moisture content depending on what it is to be used for:

• indoor wood working around 10 to 15% moisture content
• furniture building around 6 to 10%

Wood strives to have a moisture content which is in equilibrium with the air. Thus, if you are in the summer with above 70% relative air humidity and find wood that is as dry as is often recommended for furniture (around 6 to 10%), you have found wood which has not been in that air for a long time. On the other hand, in the winter with relative air humidity around 30%, you can be lucky and find wood which has a moisture content slightly above 6% and which is still drying for its first time.

Adopt wood moisture recommendations to circumstances

In order to answer the question on what moisture content your wood should have, you need to adjust the above recommendations based on what moisture content your air normally has.

• In cold climates at the beginning of spring, you should be able to find wood which already in the lumberyard is at, or close to, the furniture dry range above. In the diagram above you see that the top dark blue line depicting drying wood is below 10% when relative humidity in the air is below around 40%. Thus, where the climate is cold, finding dry wood in ordinary lumberyards should be possible part of the year
• In the beginning of autumn, you should, for most areas in the world, expect all wood not specifically bought as furniture dry to have a moisture content above the furniture dry interval. In the diagram you see that the bottom light blue line depicting wood absorbing humidity is above 12%. Thus, you could use that wood if you just thought it had been drier before.