A tube steel column is required to have 1 inch of SFRM thickness. What is the lowest allowable individual thickness measurement?

The requirement for a spray-applied fire-resistive material (SFRM) thickness of 1 inch on a tube steel column is typically established in building codes and standards. When assessing the individual thickness measurement of the SFRM, it is essential to comply with the specified minimum thickness criteria.

In this case, if the requirement is clearly stated as 1 inch of SFRM thickness, then the lowest allowable measurement that meets that requirement must also be 1 inch. This means that any measurement less than 1 inch would not satisfy the fire safety performance expectations set forth in the applicable standards.

Choosing a measurement below 1 inch, such as 1/2 inch or 3/4 inch, would not provide the necessary level of fire protection as anticipated by the requirement. Similarly, a thickness of 1-1/4 inches would exceed the minimum requirement but is not the lowest allowable thickness as specified. Therefore, the only correct response is a thickness of 1 inch, ensuring the fireproofing applied will meet the necessary criteria for adequate fire resistance.