Question concerning ASTM E119. Fire ratings.

[codeguy]

I am a code official and having difficulty verifiing fire ratings of various assmeblies. My most important question is, what is the fire rating for a typical 2 x 4 studded wall w/ R-11 insulation and 5/8" fire rock? Any help is appreciated.

 

[Ron]

Assuming non-combustible studs, I'm fairly sure this would have a 1-hour rating. I can't find my reference at the moment. You might check the UL Fire Resistance Manual if you have one or if library nearby.