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
3 Hour Fire-Rated Construction
• 3/4" Levelrock floor underlayment
– 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
UL Des K906 B-104
clg. wt. 3 • 5/8" Sheetrock Firecode C Core gypsum panels UL Des J502, B-105
– metal furring channel 24" o.c. J504
– joints finished
10 1 ⁄4"
22 3 ⁄4"
20 3 ⁄4"
22"
22"
– precast 2-3/4" normal weight (J502) or
2-1/2" lightweight (J504)
concrete units with 6" deep stems 48" o.c.
• 5/8" or 3/4" FR-83 acoustical ceiling panels UL Des D218 B-106
• DXLP (with Types PSS, PSSP, PSR and PSRP
metal ceiling pans), DXL, DXLZ or SDXL Susp
Exp Grid System
– light fixture and air duct optional
– 3-1/4" concrete on 1-1/2" steel roof deck
• 5/8" or 3/4" FR-83 or FR-4 or 3/4" FR-X1 UL Des D219 DXLA, DXLZA or SDXLA Susp Exp Grid B-107
acoustical ceiling panels
System may be used instead, but fire
• DXL, DXLZ or SDXL Susp Exp Grid System
rating is limited to 2 hours; DXLT or
– light fixture and air duct optional
DXLTZ Susp Exp Grid System may be
– 3-1/4" concrete on cellular and 3-1/2" concrete
also used, but fire rating is limited to
on fluted steel floor units
1-1/2 hours
• 5/8" FR-81, FR-4 or M; 5/8" or 3/4" FR-83; UL Des J201 B-108
or 3/4" FR-X1 acoustical ceiling panels
• DXL, DXLA, DXLT, DXLTZ, DXLZ, DXLZA, DXLTA,
DXLTZA, SDXL or SDXLA Susp Exp Grid System
– 2-1/2" concrete deck with 6" deep pan beam
• 5/8" or 3/4" FR-83 or 3/4" FR-X1, AP, AP-1, UL Des J202 B-109
AP-2 or AP-3 acoustical ceiling panels
• DXL, DXLT, DXLTZ, DXLZ or SDXL Susp Exp
Grid System
– light fixture and air duct optional
– 2" prestressed concrete units with 6" deep stems
44 USG Fire-Resistant Assemblies
DXLTA or DXLTZA Susp Exp Grid System
may be used instead, but fire rating is
limited to 1-1/2 hours