Moisture Mapping A Guide to Understanding Wood Moisture Content

Wood Moisture Content

Moisture content refers to the amount of moisture present within wood fibers, typically expressed as a percentage of the wood's oven-dry weight. Understanding wood moisture content is crucial because excessive moisture can lead to various issues in woodworking projects, such as swelling, cracking, and mold growth.

What should the moisture content of wood be before painting?

Before painting wood, it is essential to ensure that its moisture content is within an acceptable range. Painting on wood with high moisture content can cause the paint to peel or crack as the wood dries and shrinks. The moisture content of wood should be between 7% and 14% before painting. Here are some methods to determine the moisture content of wood:

• Moisture meter: This device measures the electrical resistance of wood to estimate moisture content.
• Weighing and drying: Weigh the wood, then dry it in an oven and weigh it again. The difference in weight gives an indication of moisture content.
• Appearance: Dry wood generally appears lighter in color, has less luster, and feels harder than wet wood.

By controlling the moisture content of wood before painting, you can ensure that the paint adheres properly and the finished product is durable and aesthetically pleasing.