40 Hour Property and Building Inspection Practice Test

Joists are typically spaced how many inches on center?

1. 10 or 12 inches

2. 14 or 16 inches

3. 16 or 24 inches

4. 20 or 22 inches

The correct answer is: 16 or 24 inches

Joists are typically spaced 16 or 24 inches on center in residential and commercial construction. This spacing is designed to provide adequate structural support while allowing for flexibility in the placement of insulation, wiring, and other utility components. The 16-inch spacing is common because it aligns well with standard sheet goods like plywood or drywall, allowing for easier installation and minimizing waste. The 24-inch spacing is often utilized in areas where increased load-bearing capacity is required, and it helps in reducing material costs by using fewer joists over a given span. This standard spacing is important for maintaining structural integrity and ensuring that loads are distributed evenly across the framework, minimizing sagging or structural failure over time. Understanding the significance of these spacing measurements is crucial for anyone involved in property and building inspection, as it directly impacts the safety and durability of the construction.