What is the required rafter bearing minimum?

The correct answer of 1.5 inches reflects the code requirements that ensure proper structural integrity and load transfer in residential construction. This standard is based on the need for adequate bearing length to support the roof's weight and any additional loads that may be applied, such as snow or maintenance activities.

In many building codes, a 1.5-inch bearing is often specified for roof rafters resting on walls or beams. This length helps to distribute the forces evenly, reducing the risk of structural failure at the point where the rafter meets the supporting structure. It also accommodates potential movement or settling over time, ensuring longevity and safety.

While other options suggest longer bearing lengths, the specified minimum of 1.5 inches provides a practical balance between safety and efficiency in construction. Excessively long bearing lengths could introduce unnecessary material costs and complicate the roof framing, whereas insufficient lengths may not meet structural requirements and could lead to issues over time. Thus, the 1.5-inch standard has been established as a reliable benchmark for rafter bearing in residential buildings.