North Carolina Building Contractor License Practice Exam

Which type of nails are used to face nail jack rafters to hips?

1. 10d common nails

2. 12d common nails

3. 16d common nails

4. 20d common nails

The correct answer is: 16d common nails

The appropriate choice of using 16d common nails for face nailing jack rafters to hips is based on the structural requirements and the dimensions of materials typically involved in framing. 16d nails, which are approximately 3.5 inches long, provide sufficient length to securely attach the jack rafters to the hip rafters or beams, ensuring that the connection can withstand the loads imposed on the roof structure. The thickness of the members being fastened often requires nails of this length to create a strong and stable connection. In residential construction, jack rafters are usually positioned at a smaller angle and are attached to the hips, which bear the load of the roof structure. The use of nails that are too short, such as 10d or 12d, may not offer adequate penetration into the structural members, leading to weaker connections that could compromise the roof’s integrity. Additionally, 20d nails are generally longer than necessary for this type of fastening, which can cause issues such as splitting the wood. Therefore, the selected 16d common nails strike an ideal balance between length and structural integrity, making them the standard choice for this application in North Carolina building practices.