What is the minimum thickness of metal runners and studs used in an acoustical partition?

• A. 2 1/2 inches
• B. 1 1/2 inches
• C. 3 inches
• D. 2 inches

Answer: (A)

When evaluating acoustical partitions, the depth of the metal framing matters because a deeper frame creates a larger air cavity and more mass for the wall assembly to resist sound transmission. Using a minimum depth of two and a half inches provides enough room to attach drywall on both sides, plus room for insulation or other decoupling components, which together improve sound isolation without making the wall assembly impractically thick. Thinner profiles, like 1-5/8 inches, limit space for insulation and the additional mass and decoupling elements needed to meet typical acoustic performance, leading to poorer sound ratings. Therefore, two and a half inches is the standard minimum depth that supports adequate acoustical performance in partitions.