Fire-Resistant Assemblies - USG Corporation

B Floor/Ceilings
Structural Concrete
2 Hour Fire-Rated Construction Acoustical Performance Reference
Construction Detail Description Test Number STC Test Number Index
• 1" Levelrock floor underlayment UL Des J917 B-96
– 4' or 8' wide precast concrete units
– grout 3500 psi
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J919 B-97
– precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J920 B-98
– precast concrete units
• 1" Levelrock floor underlayment UL Des J924 B-99
– 8-10" thick precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J927 B-100
– 6", 8", 10", or 12" thick precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J931 B-101
– 8", 10", or 12" thick precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J957 B-102
– 8", 10", or 12" thick precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
• 3/4" Levelrock floor underlayment UL Des J966 B-103
– 8" thick precast concrete units
• optional SRM-25 or SRB sound mat
– floor topping thickness should be a minimum
of 1" if using sound mat
43 USG Fire-Resistant Assemblies