In SFRM thickness testing, how many thickness measurements can be less than the specified thickness?

In Spray Applied Fire-Resistive Material (SFRM) thickness testing, the requirement is that only one thickness measurement can be less than the specified thickness. This standard allows for some variability in the application of the material, recognizing that while consistency is important, minor discrepancies can occur due to factors such as application techniques or environmental conditions during installation.

The significance of this guideline lies in ensuring that the SFRM performs effectively in providing the intended fire resistance. If multiple measurements fall below the specified thickness, it raises concerns regarding the fireproofing's ability to meet safety standards and could compromise the structural integrity during a fire event. Therefore, limiting the allowable discrepancy to just one measurement ensures a balance between practical application challenges and the necessary compliance with fire safety requirements.