For nailing ceiling joists to the top plate, how many 8D nails should you use at a minimum?

When nailing ceiling joists to the top plate, it is standard practice to use a minimum of three 8D nails. The use of three nails provides sufficient holding power to ensure that the joists are securely fastened to the top plate, which is critical for stability and structural integrity in framing. This guideline is based on best practices in carpentry, which aim to prevent issues such as shifting or sagging over time.

Using fewer nails, such as two, may not provide adequate strength to support the ceiling structure, leading to potential failures during use or in response to loading. Additionally, opting for larger gauge nails, like 16D, would provide greater holding power; however, the requirement specifically calls for the use of 8D nails, indicating that three of these will suffice for a robust connection without unnecessary oversizing of fasteners. This choice aligns with accepted building codes and practical construction standards, ensuring a safe and durable installation.