Fire-Resistant Assemblies - USG Corporation

B
Floor/Ceilings
Steel Framed
2 Hour Fire-Rated Construction Steel Bar Joist Framing Acoustical Performance Reference
Construction Detail Description Test Number STC Test Number Index
21 3 ⁄8"
22 1 ⁄2"
21 3 ⁄8"
26"
23 1 ⁄4"
23"
20 1 ⁄2"
• 5/8" or 3/4" FR-83; 5/8" or 3/4" FR-2; or UL Des G227 When the FR-2 ceiling panels are used, B-27
3/4" Astro-FR acoustical ceiling panels
• DXL, SDXL or DXLZ or Susp Exp Grid System
– light fixture and air duct optional
– 2-1/2" concrete deck on riblath
– steel bar joists, 24" o.c.
the fire rating is limited to 2 hours.
• 3/4" AP or AP-3 acoustical ceiling panels UL Des G228 B-28
• DXL, DXLZ or SDXL Susp Exp Grid System
– light fixture and air duct optional
– 2-1/2" concrete deck on riblath
– steel bar joists, 24" o.c.
• 1/2" Levelrock floor underlayment UL Des G230 B-29
– type 10J2 steel joist spaced maximum 4' o.c.
• 5/8" or 3/4" FR-83; 5/8" or 3/4" FR-2; 3/4"
FR-X1; or 3/4" Astro-FR
• DXL, DXLA, DXLZ, DXLZA, SDXL, SDXLA or
ZXLA Susp Exp Grid System
– 2" T&G building units
– steel bar joists, 4' o.c.
– W8 x 31 beam
• 3/4" FR-83 acoustical ceiling panels UL Des G231 B-30
• DXL, DXLA, DXLZ, DXLZA, SDXL, SDXLA or
ZXLA Susp Exp Grid System
– light fixture and air duct optional
– 2-1/2" concrete deck on riblath
– steel bar joists, 24" o.c.
• 5/8" or 3/4" FR-83, 5/8" or 3/4" FR-2, 3/4" UL Des G234 B-31
FR-X1 or 3/4" Astro-FR acoustical ceiling panels
• Susp Exp Grid System
– light fixture optional
– 2-1/2" concrete deck on riblath
– steel bar joists, 24" o.c.
29 USG Fire-Resistant Assemblies