How many SFRM thickness measurements are required for a metal deck that uses a flat plate?

For a metal deck using a flat plate, selecting four thickness measurements for the spray-applied fire-resistive material (SFRM) is essential for ensuring that the fireproofing is applied uniformly and meets the required specifications for fire resistance. The reason this number is important relates to the need for a comprehensive assessment of the SFRM's coverage and consistency across the structure.

By measuring four times, one can account for any variations that may occur during application. These variations could arise from differences in application techniques, equipment used, or environmental conditions during the spraying process. A minimum number of measurements helps ensure the integrity of the fireproofing layer and confirms that it adheres to the necessary codes and standards.

Conducting fewer measurements may lead to an inadequate understanding of the thickness across the entire area, increasing the risk that some parts may not provide sufficient fire resistance in case of a fire. Therefore, taking a total of four thickness measurements strikes a balance between thoroughness and practicality in assessing the overall quality of the fireproofing application.