Page 441 - 2018_IRC

ROOF-CEILING CONSTRUCTION

RAFTER SPAN
WITHOUT RAFTER SUPPORT BRACE

RAFTER RIDGE MEMBER
SEE FIGURE R804.3.2.4
RAFTER SPAN
WITH RAFTER SUPPORT BRACE RAFTER BOTTOM FLANGE
BRACING (FLAT STRAP,
350S162-33 MIL C-SECTION,
OR TRACK SECTION)
HEEL JOINT
SEE FIGURE
C-SECTION OR TRACK INSTALLED R804.3.1.1
AT 4 FT. O.C. TO RAFTER SUPPORT BRACE
350s162-33 MIL C- OR TRACK
45° SECTION OR STRAP FOR CEILING
MIN JOIST TOP FLANGE BRACING
6 IN. MAX. TO CENTER
CEILING JOIST
OF SCREW PATTERN EAVE OVERHANG
2 FT. MAX.
½ IN. GYPSUM BOARD
WHEN INSTALLED RAFTER SUPPORT
BRACE SHALL BE A MINIMUM OF CEILING JOIST SPAN
350s162-33 MIL C-SECTION, CONNECTED
TO EACH CEILING JOIST AND RAFTER LOAD-BEARING WALL SHALL BE
WITH 4 SCREWS AT EACH END (COPE INSTALLED WHEN RAFTER BRACE
FLANGES OF BAR AT CEILING JOIST IS USED
CONNECTION OR USE GUSSET PLATE)
LOAD-BEARING WALL
LOAD-BEARING WALL

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.
FIGURE R804.3
COLD-FORMED STEEL ROOF CONSTRUCTION

TABLE R804.3
ROOF FRAMING FASTENING SCHEDULE a, b
DESCRIPTION OF BUILDING ELEMENTS NUMBER AND SIZE OF FASTENERS a SPACING OF FASTENERS
6 o.c. on edges and 12
Roof sheathing (oriented strand board or plywood) No. 8 screws o.c. at interior supports. 6
to rafter
o.c. at gable end truss
Gable end truss to endwall top track No. 10 screws 12 o.c.
Minimum No. 10 screws, in accordance with Evenly spaced, not less
Rafter to ceiling joist 1
Table R804.3.1.1(3) than /  from all edges.
2
Ultimate Design Wind Speed
Ceiling Joist Roof Span (ft) (mph) and Exposure Category
Spacing (in.) 126 B <139 B 126 C <139 C
110 C 115 C
2 4 2 2 2 3
2 8 2 2 3 3
Ceiling joist or
roof truss to top 16 3 2 2 2 3 4 Each ceiling joist
track of bearing 3 6 2 2 3 4 or roof truss
wall b 4 0 2 2 3 4
2 4 2 2 3 4
2 8 2 2 4 5
24 3 2 2 3 4 5
3 6 2 3 4 6
4 0 2 3 5 6
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mil = 0.0254 mm.
a. Screws are a minimum No. 10 unless noted otherwise.
b. Indicated number of screws shall be applied through the flanges of the truss or ceiling joist or through each leg of a 54 mil clip angle. See Section R804.3.8
for additional requirements to resist uplift forces.

416 2018 INTERNATIONAL RESIDENTIAL CODE ®
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