Which testing standard covers SFRM thickness testing?

The correct choice is based on the standard that specifically addresses the measurement of thickness for Spray Fire-Resistant Materials (SFRM). ASTM E 605 provides the methodology for testing the thickness of spray-applied fire-resistive materials, which is essential for ensuring that the fireproofing application meets the designed specifications for fire resistance and performance. Proper thickness is critical as it directly affects the material's fire-resistance capabilities, and compliance with this standard helps in verifying that the installed materials conform to the necessary codes and requirements.

The other standards mentioned do not specifically focus on SFRM thickness testing. While they may cover other aspects of fire resistance materials or construction processes, ASTM E 605 is explicitly dedicated to the evaluation of thickness, making it the most relevant choice for this question.