What is the maximum moisture content allowed for lumber according to the National Building Code?

The maximum moisture content allowed for lumber according to the National Building Code is 12 percent. This standard is established to ensure the structural integrity and durability of wood products used in construction. Excessively wet lumber can lead to a variety of problems, such as warping, twisting, or fungal decay, which can jeopardize the quality and lifespan of the building.

Maintaining the moisture content at or below 12 percent minimizes these risks. It is particularly important for wood that will be used in enclosed structures, where moisture may not dissipate easily. This guideline is widely accepted in the construction industry to promote safety and performance in building projects. Thus, adhering to this moisture limit is critical for ensuring that lumber behaves predictably under load and during seasonal changes in humidity.