When measuring tube steel SFRM thickness, how many measurements can be less than the specified thickness?

In the context of measuring the thickness of Spray-Applied Fire-Resistant Materials (SFRM) on tube steel, the standard requirement is that all measurements must meet or exceed the specified thickness. This is critical because the fire resistance of the material is directly tied to its thickness; insufficient coverage can compromise the integrity of the fireproofing and the safety of the structure.

When conducting inspections, if even a single measurement falls below the specified thickness, it indicates that the fireproofing may not perform adequately in the event of a fire. This stringent requirement ensures that the protective qualities of the SFRM are maintained consistently across all points on the structure. Therefore, the correct understanding is that no measurements can be less than the specified thickness; all readings must comply to ensure proper safety and effectiveness of the fireproofing system.