Building Code Requirements For occupancies such as stores, apartments, offices, and other commercial and industrial uses, building codes commonly require floor/ceiling and wall assemblies to be fire-resistance rated in accordance with standard fire tests.     Depending on the application, wall assemblies may need to be rated either from one side or both sides. For specific exterior wall applications, the model building codes allow wood-frame, wood-sided walls to be tested for exposure to fire from the inside only. Rating for both interior and exterior fire exposure is only required when the wall has a fire separation distance of less than 5 feet. Code recognition of one and two-hour wood-frame wall systems is also predicated on successful fire and hose stream testing in accordance with ASTM E119, Standard Test Methods for Fire Tests of Building Construction Materials. Fire Tested Assemblies Fire-rated wood-frame assemblies can be found in a number of sources including the IBC, Underwriters Laboratories (UL) Fire Resistance Directory, Intertek Testing Services'

Directory of Listed Products, and the Gypsum Association's Fire Resistance Design Manual. The American Forest & Paper Association (AF&PA) and its members have tested a number of wood-frame fire-rated assemblies. Descriptions of successfully tested lumber wall assemblies are provided in Table 1 for one-hour rated wall assemblies and Table 2 for two-hour rated wall assemblies. Lumber shall be identified by the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with the American Softwood Lumber Standard (PS 20). Descriptions of successfully tested I-joist floor assemblies are provided in Table 3 for one-hour rated floor/ceiling assemblies and Table 4 for two-hour rated floor/ceiling assemblies. I-joists are required to comply with the latest version of ASTM D5055, Standard Specification for Establishing and Monitoring Structural Capacities of Prefabricated Wood I-Joists. Additional tests are being conducted and the Tables will be updated periodically. Conclusions Wood-frame assemblies are used in architectural designs because of their adaptability to style preferences, ease and economies of construction, and energy-saving performance.

Table 1: One-Hour Fire-Rated Loadbearing Wood-Frame Wall Assemblies
Assemblies Rated From Both Sides
Studs	Insulation	Sheathing on Both Sides		Fasteners	Details
2x4 @ 16" o.c.	3½" mineral wool batts	5/8" Type X Gypsum Wallboard (H)		2¼" #6 Type S drywall screws @ 12" o.c.	WS4-1.1
2x6 @ 16" o.c.	(none)	5/8" Type X Gypsum Wallboard (H)		2¼" #6 Type S drywall screws @ 7" o.c.	WS6-1.1
2x6 @ 16" o.c.	5½" mineral wool batts	5/8" Type X Gypsum Wallboard (H)		2¼" #6 Type S drywall screws @ 12" o.c.	WS6-1.2
2x6 @ 16" o.c.	R-19 fiberglass insulation	5/8" Type X Gypsum Wallboard (V)		2¼" #6 Type S drywall screws @ 12" o.c.	WS6-1.4
Assemblies Rated From One Side (Fire on Interior Only)
Studs	Insulation	Sheathing		Fasteners
2x4 @ 16" o.c.	3½" mineral wool batts	I	5/8" Type X Gypsum Wallboard (H)	2¼" #6 Type S drywall screws @ 12" o.c.	WS4-1.2
		E	3/8" wood structural panels (V)	6d common nails @ 6" edges/12" field
2x4 @ 16" o.c.	4 mil polyethylene  3½" mineral wool batts	I	5/8" Type X Gypsum Wallboard (V)	6d cement coated box nails @ 7" o.c.	WS4-1.3
		E	½" fiberboard (V)	1½" roofing nails @ 3" edges/6" field
			3/8" hardboard shiplapped panel siding	8d galv. nails @ 4" edges/8" field
2x6 @ 16" o.c.	5½" mineral wool batts	I	5/8" Type X Gypsum Wallboard (H)	2¼" #6 Type S drywall screws @ 12" o.c.	WS6-1.3
		E	7/16" wood structural panels (V)	6d common nails @ 6" edges/12" field
2x6 @ 16" o.c.	R-19 fiberglass insulation	I	5/8" Type X Gypsum Wallboard (V)	2¼" #6 Type S drywall screws @ 12" o.c.	WS6-1.5
		E	3/8" wood structural panels (V)	6d common nails @ 6" edges/12" field
H- applied horizontally with vertical joints over studs                       I- Interior sheathing V- applied vertically with vertical joints over studs                           E- Exterior sheathing

Table 2: Two-Hour Fire-Rated Loadbearing Wood-Frame Wall Assemblies
Assemblies Rated From Both Sides
Studs	Insulation	Sheathing on Both Sides		Fasteners	Details
2x6 @ 24" o.c.	5½" mineral wool batts	B	5/8" Type X Gypsum Wallboard (H)	2¼" #6 Type S drywall screws @ 24" o.c.	WS6-2.1
		F	5/8" Type X Gypsum Wallboard (H)	2¼" #6 Type S drywall screws @ 8" o.c.
H- applied horizontally with vertical joints over studs B- Base layer sheathing                                                                F- Face layer sheathing

Table 3: One-Hour Fire-Rated Wood Floor/Ceiling Assemblies
Wood I-Joist Assemblies
Joists	Insulation	Furring	Ceiling Sheathing		Fasteners	Details
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 5.25 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/4"	1-1/2"  mineral wool batts (2.5 pcf-nominal) Resting on hat-shaped channels	Hat-shaped channels	F	5/8" Type C Gypsum Wallboard (GWB)	1-1/8" Type S drywall screws spaced 12" o.c. in GWB field spaced 8" o.c. at GWB end joints (see fastening details)	WIJ-1.1
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 5.25 sq. in.   Min. web thickness: 7/16"   Min. I-joist depth: 9-1/4"	1-1/2"  mineral wool batts (2.5 pcf-nominal) Resting on resilient channels	Resilient channels	F	5/8" Type C Gypsum Wallboard (GWB)	1" Type S drywall screws spaced 12" o.c. in GWB field spaced 8" o.c. at GWB end joints (see fastening details)	WIJ-1.2
I-joists @ 24" o.c.   Min. flange depth: 1-5/16"   Min. flange area: 2.25 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/4"	2"  mineral wool batts (3.5 pcf-nominal) Resting on 1x4 setting strips	Resilient channels	F	5/8" Type C Gypsum Wallboard (GWB)	1-1/8" Type S drywall screws spaced 7" o.c. in GWB field spaced 7" o.c. at GWB end joints (see fastening details)	WIJ-1.3
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 3.45 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/4"	1"  mineral wool batts (6 pcf-nominal) Resting on hat-shaped channels under I-joist bottom flange	Hat-shaped channels supported by CSC clips	F	1/2" Type C Gypsum Wallboard (GWB)	1" Type S drywall screws spaced 12" o.c. in GWB field spaced 6" o.c. at GWB end joints (see fastening details)	WIJ-1.4
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 2.25 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/4"	(none)	(none)	B	1/2" Type C Gypsum Wallboard (GWB)	1" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints	WIJ-1.5
			F	1/2" Type C Gypsum Wallboard (GWB)	1-5/8" Type S drywall screws spaced 12" o.c. in GWB field spaced 8" o.c. at GWB end joints 1-1/2" Type G drywall screws spaced 8" o.c. at GWB end joints (see fastening details)
I-joists @ 24" o.c.   Min. flange depth: 1-5/16"   Min. flange area: 1.95 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/2"	(none)	Resilient channels	B	1/2" Type X Gypsum Wallboard (GWB)	1-1/4" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints	WIJ-1.6
			F	1/2" Type X Gypsum Wallboard (GWB)	1-5/8" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints 1-1/2" Type G drywall screws spaced 8" o.c. at GWB end joints (see fastening details)
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 2.25 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/2"	Fiberglass batts Resting on resilient channels	Resilient channels	B	1/2" Type X Gypsum Wallboard (GWB)	1-1/4" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints	WIJ-1.7
			F	1/2" Type X Gypsum Wallboard (GWB)	1-5/8" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints 1-1/2" Type G drywall screws spaced 8" o.c. at GWB end joints (see fastening details)
B- Base layer sheathing                                                                F- Face layer sheathing

Table 4: Two-Hour Fire-Rated Wood Floor/Ceiling Assemblies
Wood I-Joist Assemblies
Joists	Insulation	Furring	Ceiling Sheathing		Fasteners	Details
I-joists @ 24" o.c.   Min. flange depth: 1-1/2"   Min. flange area: 2.25 sq. in.   Min. web thickness: 3/8"   Min. I-joist depth: 9-1/4"	3-1/2" fiberglass insulation Supported by stay wires spaced 12" o.c.	(none)	B	5/8" Type C Gypsum Wallboard (GWB)	1-5/8" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints	WIJ-2.1
		Hat-shaped channels	M	5/8" Type C Gypsum Wallboard (GWB)	1" Type S drywall screws spaced 12" o.c. in GWB field spaced 12" o.c. at GWB end joints
			F	5/8" Type C Gypsum Wallboard (GWB)	1-5/8" Type S drywall screws spaced 8" o.c. in GWB field spaced 8" o.c. at GWB end joints (see fastening details)
B- Base layer sheathing  (direct attached)                                      M- Middle layer sheathing                                   F- Face layer sheathing