Q: How are fire ratings of Concrete Masonry assemblies calculated, and for fire code compliance, are listing services such as UL® required?
-Fire Rating Expertise Desired
A: Dear FRED: Section 721 of the IBC recognizes several methods to calculate the fire resistance for CMU walls. The equivalent thickness method is the most commonly used, and the most cost effective. It takes into account extensive industry research, the results of ASTM E-119 testing and aggregate type. Equivalent thickness...Read More