North Carolina Building Contractor License Practice Exam

Wall sheathing boards should be spaced how much apart?

1. 1 time thickness

2. 2 times thickness

3. 2.5 times thickness

4. 3 times thickness

The correct answer is: 2.5 times thickness

The spacing for wall sheathing boards is critical to ensure that the wall system can accommodate expansion and contraction due to temperature changes and humidity levels. When using wood sheathing, the boards are generally spaced at a distance that allows for this movement while maintaining structural integrity. The correct guideline is to space the boards 2.5 times the thickness of the boards. This spacing helps to prevent issues related to warping, cupping, or other forms of deformation that can occur when the boards expand. If the spacing is too tight, it can lead to pressure buildup and potential damage to the boards or other components of the wall system. Understanding this principle is essential for anyone involved in construction to ensure long-lasting and resilient structures. This practice reflects industry standards and is based on the material properties of wood, taking into consideration its behavior in varying environmental conditions. Proper spacing not only supports the sheathing itself but also contributes to the overall performance of the building envelope.