What is the distance apart for readings when testing SFRM on a joist?

When testing Spray-Applied Fire-Resistive Material (SFRM) on a joist, a distance of 12 inches apart for readings is standard practice. This distance is essential for ensuring that the testing method captures the uniformity and thickness of the applied fireproofing material. Adequate spacing allows for a representative sampling across the joist without overlapping measurements that could skew the results. By taking readings at this interval, inspectors can effectively evaluate the surface’s fire-resistive properties, ensuring compliance with safety standards and proper application techniques. This practice helps maintain accurate and reliable assessments of fireproofing integrity, which is crucial in fire protection engineering.