ICC Commercial Building Inspector Practice Test

What is the maximum spacing allowed between fasteners used on a gypsum board diaphragm ceiling?

1. 5 inches on center

2. 6 inches on center

3. 7 inches on center

4. 8 inches on center

The correct answer is: 7 inches on center

The maximum spacing allowed between fasteners used on a gypsum board diaphragm ceiling is 7 inches on center. This specification is important because it ensures the structural integrity and adequate support of the ceiling assembly. Gypsum board, commonly used in building construction for its fire-resistant properties, must be securely fastened to prevent sagging, cracking, or failure, especially in areas where dynamic loads may occur, such as in ceilings that bear additional weight from fixtures or insulation. By adhering to the 7-inch spacing guideline, the connection between the gypsum board and the framing members is optimized, allowing for even distribution of forces and minimizing the potential for movement or separation over time. Properly following this standard contributes to the overall durability and safety of the ceiling system, ensuring it meets performance requirements as outlined in building codes. In contrast, spacings that are too large could result in inadequate fastening, compromising the ceiling's structural performance. Thus, maintaining this maximum spacing is critical when installing gypsum board to ensure adherence to safety and performance standards.