The minimum unit used to express metal lath weight in SFRM applications is which?

• A. Pounds per square yard
• B. Pounds per cubic yard
• C. Kilograms per cubic meter
• D. Ounces per cubic yard

Answer: (B)

In sprayed fire-resistive material (SFRM) work, densities are expressed as weight per volume because you’re concerned with how much material exists in a given thickness. Metal lath weight contributes to the overall density of the system, so it’s reported as a weight per unit volume. The standard US customary unit for this in SFRM applications is pounds per cubic yard, which ties directly to thickness-based calculations and field specifications. Pounds per square yard describes weight per area and doesn’t account for thickness, kilograms per cubic meter is a metric unit (not the common standard in this context), and ounces per cubic yard is an impractically small unit for typical densities. Therefore, the appropriate unit is pounds per cubic yard.