California Residential Inspector Practice Exam

What is the minimum diameter for anchor bolts securing wood sill plates to concrete foundations?

1. 3/8 inch

2. 1/2 inch

3. 5/8 inch

4. 3/4 inch

The correct answer is: 1/2 inch

The minimum diameter for anchor bolts securing wood sill plates to concrete foundations is specified as 1/2 inch. This standard is established to ensure adequate strength and stability in the connection between the wood structure and the concrete foundation, which is crucial for the structural integrity of the building. Larger diameter bolts provide enhanced holding capacity, but 1/2 inch is considered the minimum to effectively resist lateral loads, such as those caused by wind or seismic activity. This standard also takes into account factors such as the material properties of both the concrete and the wood, as well as the need for durability and resistance to pull-out forces. Using a diameter smaller than 1/2 inch might not provide sufficient anchorage, leading to potential failures or issues in securing the framing to the foundation, which could compromise the building's overall safety. While larger diameters are available and can be used for additional strength, the requirement for 1/2 inch anchors ensures a minimum level of structural reliability.