Wood Moisture Content (%MC) is the measure of the amount of water in wood, and is a critical issue when working with any wood materials.
As a hygroscopic material, wood absorbs or desorbs moisture until it reaches equilibrium with its surroundings—the wetter the air, the wetter the wood, and vice versa. Wood not in equilibrium may swell as it takes on moisture, or crack and split as it dries out.
Oversaturated wood may grow mold.
To protect wood, it’s important to use wood moisture meters to asses %MC and if the wood has reached EMC.