Copyright

Preface

Effective Use of the International Residential Code

Legislation

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Chapter 11 [Re] Energy Efficiency

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment and Appliances

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 19 Special Appliances, Equipment and Systems

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 22 Special Piping and Storage Systems

Chapter 23 Solar Energy Systems

Chapter 24 Fuel Gas

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 32 Traps

Chapter 33 Storm Drainage

Chapter 34 General Requirements

Chapter 35 Electrical Definitions

Chapter 36 Services

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 38 Wiring Methods

Chapter 39 Power and Lighting Distribution

Chapter 40 Devices and Luminaires

Chapter 41 Appliance Installation

Chapter 42 Swimming Pools

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

Chapter 44 Referenced Standards

Appendix A Sizing and Capacities of Gas Piping

Appendix B Sizing of Venting Systems Serving Appliances Equipped With Draft Hoods, Category I Appliances, and Appliances Listed for Use With Type B Vents

Appendix C Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems

Appendix D Recommended Procedure for Safety Inspection of an Existing Appliance Installation

Appendix E Manufactured Housing Used as Dwellings

Appendix F Radon Control Methods

Appendix G Swimming Pools, Spas and Hot Tubs

Appendix H Patio Covers

Appendix I Private Sewage Disposal

Appendix J Existing Buildings and Structures

Appendix K Sound Transmission

Appendix L Permit Fees

Appendix M HOME DAY CARE—R-3 OCCUPANCY

Appendix N Venting Methods

Appendix O Automatic Vehicular Gates

Appendix P Sizing of Water Piping System

Appendix Q Icc International Residential Code Electrical Provisions/National Electrical Code Cross Reference

The provisions of this chapter shall control the design and construction of the floors for all buildings including the floors of attic spaces used to house mechanical or plumbing fixtures and equipment.
Floor construction shall be capable of accommodating all loads according to Section R301 and of transmitting the resulting loads to the supporting structural elements.
Floor assemblies, not required elsewhere in this code to be fire-resistance rated, shall be provided with a 1/2-inch (12.7 mm) gypsum wallboard membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member.
Exceptions:
1. Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with Section P2904, NFPA13D, or other approved equivalent sprinkler system.
2. Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.
3. Portions of floor assemblies can be unprotected when complying with the following:
3.1. The aggregate area of the unprotected portions shall not exceed 80 square feet per story
3.2. Fire blocking in accordance with Section R302.11.1 shall be installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly.
4. Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.
Load-bearing dimension lumber for joists, beams and girders shall be identified by a grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20. In lieu of a grade mark, a certificate of inspection issued by a lumber grading or inspection agency meeting the requirements of this section shall be accepted.
Preservative treated dimension lumber shall also be identified as required by Section R317.2.
Blocking shall be a minimum of utility grade lumber. Subflooring may be a minimum of utility grade lumber or No. 4 common grade boards.
Approved end-jointed lumber identified by a grade mark conforming to Section R502.1 may be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required elsewhere in this code to have a fire-resistance rating shall have the designation “Heat Resistant Adhesive” or “HRA” included in its grade mark.
Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D 5055.
Glued laminated timbers shall be manufactured and identified as required in ANSI/AITC A190.1 and ASTM D 3737.
Stress grading of structural log members of nonrectangular shape, as typically used in log buildings, shall be in accordance with ASTM D 3957. Such structural log members shall be identified by the grade mark of an approved lumber grading or inspection agency. In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber-grading or inspection agency meeting the requirements of this section shall be permitted to be accepted.
Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D 5456.
Floors shall be designed and constructed in accordance with the provisions of this chapter, Figure R502.2 and Sections R317 and R318 or in accordance with AF&PA;/NDS.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE R502.2
FLOOR CONSTRUCTION

A load path for lateral forces shall be provided between floor framing and braced wall panels located above or below a floor, as specified in Section R602.10.8.

Relocated

Deleted

Spans for floor joists shall be in accordance with Tables R502.3.1(1) and R502.3.1(2). For other grades and species and for other loading conditions, refer to the AF&PA; Span Tables for Joists and Rafters.
Table R502.3.1(1) shall be used to determine the maximum allowable span of floor joists that support sleeping areas and attics that are accessed by means of a fixed stairway in accordance with Section R311.7 provided that the design live load does not exceed 30 pounds per square foot (1.44 kPa) and the design dead load does not exceed 20 pounds per square foot (0.96 kPa). The allowable span of ceiling joists that support attics used for limited storage or no storage shall be determined in accordance with Section R802.4.

TABLE R502.3.1(1)
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES
(Residential sleeping areas, live load = 30 psf, L/Δ = 360)a

JOIST SPACING (inches)SPECIES AND GRADE DEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 62 × 82 × 102 × 122 × 62 × 82 × 102 × 12
Maximum floor joist spans
(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)
12Douglas fir-larchSS12-616-621-025-712-616-621-025-7
Douglas fir-larch#112-015-1020-324-812-015-719-022-0
Douglas fir-larch#211-1015-719-1023-011-614-717-920-7
Douglas fir-larch#39-812-415-017-58-811-013-515-7
Hem-firSS11-1015-719-1024-211-1015-719-1024-2
Hem-fir#111-715-319-523-711-715-218-621-6
Hem-fir#211-014-618-622-611-014-417-620-4
Hem-fir#39-812-415-017-58-811-013-515-7
Southern pineSS12-316-220-825-112-316-220-825-1
Southern pine#112-015-1020-324-812-015-1020-324-8
Southern pine#211-1015-719-1024-211-1015-718-721-9
Southern pine#310-513-315-818-89-411-1114-016-8
Spruce-pine-firSS11-715-319-523-711-715-319-523-7
Spruce-pine-fir#111-314-1119-023-011-314-717-920-7
Spruce-pine-fir#211-314-1119-023-011-314-717-920-7
Spruce-pine-fir#39-812-415-017-58-811-013-515-7
16Douglas fir-larchSS11-415-019-123-311-415-019-123-0
Douglas fir-larch#110-1114-518-521-410-813-616-519-1
Douglas fir-larch#210-914-117-219-119-1112-715-517-10
Douglas fir-larch#38-510-813-015-17-69-611-813-6
Hem-firSS10-914-218-021-1110-914-218-021-11
Hem-fir#110-613-1017-820-910-413-116-018-7
Hem-fir#210-013-216-1019-89-1012-515-217-7
Hem-fir#38-510-813-015-17-69-611-813-6
Southern pineSS11-214-818-922-1011-214-818-922-10
Southern pine#110-1114-518-522-510-1114-517-1121-4
Southern pine#210-914-218-021-110-513-616-118-10
Southern pine#39-0 11-613-716-28-110-312-214-6
Spruce-pine-firSS10-613-1017-821-610-613-1017-821-4
Spruce-pine-fir#110-313-617-219-119-1112-715-517-10
Spruce-pine-fir#210-313-617-219-119-1112-715-517-10
Spruce-pine-fir#38-510-813-015-17-69-611-813-6

(continued)

TABLE R502.3.1(1)—continued
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES
(Residential sleeping areas, live load = 30 psf, L/Δ = 360)a

JOIST SPACING (inches)SPECIES AND GRADE DEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 62 × 82 × 102 × 122 × 62 × 82 × 102 × 12
Maximum floor joist spans
(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)
19.2Douglas fir-larchSS10-8 14-1 18-0 21-10 10-814-1 18-0 21-0
Douglas fir-larch#110-413-7 16-9 19-6 9-812-4 15-0 17-5
Douglas fir-larch#210-112-1015-818-3 9-111-614-1 16-3
Douglas fir-larch#37-89-9 11-10 13-9 6-10 8-8 10-7 12-4
Hem-firSS10-113-4 17-0 20-8 10-113-4 17-0 20-7
Hem-fir#19-1013-0 16-4 19-0 9-612-0 14-817-0
Hem-fir#29-512-515-617-1 8-1111-413-10 16-1
Hem-fir#37-8 9-9 11-10 13-9 6-10 8-8 10-7 12-4
Southern pineSS10-613-1017-821-610-613-1017-821-6
Southern pine#110-413-7 17-4 21-1 10-413-7 16-4 19-6
Southern pine#210-113-4 16-5 19-3 9-612-414-8 17-2
Southern pine#38-310-6 12-5 14-9 7-49-5 11-1 13-2
Spruce-pine-firSS9-1013-0 16-7 20-2 9-1013-0 16-7 19-6
Spruce-pine-fir#19-812-915-8 18-3 9-111-6 14-1 16-3
Spruce-pine-fir#29-812-915-818-3 9-111-614-1 16-3
Spruce-pine-fir#37-8 9-9 11-10 13-9 6-10 8-8 10-712-4
24Douglas fir-larchSS9-1113-116-820-39-1113-116-2 18-9
Douglas fir-larch#19-712-415-017-58-811-013-5 15-7
Douglas fir-larch#29-111-614-116-38-110-312-714-7
Douglas fir-larch#36-108-810-712-46-27-99-6 11-0
Hem-firSS9-412-415-919-29-412-415-9 18-5
Hem-fir#19-212-014-817-08-610-913-1 15-2
Hem-fir#28-911-413-1016-18-010-212-514-4
Hem-fir#36-10 8-8 10-7 12-4 6-2 7-9 9-6 11-0
Southern pineSS9-912-1016-519-119-912-1016-519-11
Southern pine#19-712-716-119-69-712-414-7 17-5
Southern pine#29-412-414-817-28-611-013-115-5
Southern pine#37-49-511-113-26-78-59-11 11-10
Spruce-pine-firSS9-212-115-518-99-212-115-0 17-5
Spruce-pine-fir#18-1111-614-116-38-110-312-7 14-7
Spruce-pine-fir#28-1111-614-116-38-110-312-714-7
Spruce-pine-fir#36-108-810-712-46-2 7-9 9-611-0
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
a. Dead load limits for townhouses in Seismic Design Category C and all structures in Seismic Design Categories D0, D1 and D2 shall be determined in accordance with Section R301.2.2.2.1.

TABLE R502.3.1(2)
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES
(Residential living areas, live load = 40 psf, L/Δ = 360)b

JOIST SPACING (inches)SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 62 × 82 × 102 × 122 × 62 × 82 × 102 × 12
Maximum floor joist spans
(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)
12Douglas fir-larch SS11-415-019-123-3 11-4 15-0 19-123-3
Douglas fir-larch #1 10-1114-518-522-0 10-11 14-2 17-420-1
Douglas fir-larch #2 10-914-217-920-7 10-613-3 16-318-10
Douglas fir-larch #3 8-811-013-515-7 7-11 10-0 12-314-3
Hem-fir SS 10-914-218-021-11 10-9 14-2 18-021-11
Hem-fir #1 10-613-1017-821-6 10-6 13-10 16-1119-7
Hem-fir #2 10-013-216-1020-4 10-013-1 16-018-6
Hem-fir #3 8-8 11-0 13-5 15-7 7-11 10-0 12-3 14-3
Southern pine SS 11-214-818-922-1011-214-818-922-10
Southern pine #1 10-1114-518-522-5 10-11 14-5 18-522-5
Southern pine #2 10-914-218-021-9 10-914-2 16-1119-10
Southern pine #3 9-411-1114-016-8 8-6 10-10 12-1015-3
Spruce-pine-fir SS 10-613-1017-821-6 10-6 13-10 17-821-6
Spruce-pine-fir #1 10-313-617-320-7 10-3 13-3 16-318-10
Spruce-pine-fir #2 10-313-617-320-7 10-313-316-318-10
Spruce-pine-fir #3 8-811-013-5 15-7 7-11 10-012-3 14-3
16Douglas fir-larch SS 10-413-7 17-421-1 10-413-7 17-421-0
Douglas fir-larch #1 9-1113-1 16-519-1 9-812-4 15-017-5
Douglas fir-larch #2 9-912-715-517-10 9-111-614-116-3
Douglas fir-larch #3 7-69-6 11-813-6 6-108-8 10-712-4
16Hem-fir SS 9-912-10 16-519-11 9-912-10 16-519-11
Hem-fir #1 9-612-7 16-018-7 9-612-0 14-817-0
Hem-fir #2 9-112-015-217-7 8-1111-413-1016-1
Hem-fir #3 7-6 9-6 11-8 13-6 6-10 8-8 10-7 12-4
Southern pine SS 10-213-417-020-910-213-417-020-9
Southern pine #1 9-1113-1 16-920-4 9-1113-1 16-419-6
Southern pine #2 9-912-10 16-118-10 9-612-414-817-2
Southern pine #3 8-110-3 12-214-6 7-49-5 11-113-2
Spruce-pine-fir SS 9-612-7 16-019-6 9-612-7 16-019-6
Spruce-pine-fir #1 9-412-3 15-517-10 9-111-6 14-116-3
Spruce-pine-fir #2 9-412-315-517-109-111-614-116-3
Spruce-pine-fir #3 7-6 9-611-8 13-66-10 8-810-712-4

(continued)

TABLE R502.3.1(2)—continued
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES
(Residential living areas, live load = 40 psf, L/Δ = 360)b

JOIST SPACING (inches)SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 62 × 82 × 102 × 122 × 62 × 82 × 102 × 12
Maximum floor joist spans
(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)(ft - in.)
19.2Douglas fir-larch SS 9-812-10 16-4 19-10 9-812-1016-419-2
Douglas fir-larch #1 9-412-4 15-0 17-5 8-1011-313-815-11
Douglas fir-larch #2 9-111-614-1 16-3 8-310-612-1014-10
Douglas fir-larch #3 6-108-8 10-7 12-4 6-37-119-811-3
Hem-fir SS 9-212-1 15-5 18-9 9-212-115-518-9
Hem-fir #1 9-011-10 14-8 17-08-810-1113-415-6
Hem-fir #2 8-711-313-10 16-1 8-210-412-814-8
Hem-fir #3 6-10 8-8 10-7 12-4 6-3 7-11 9-8 11-3
Southern pine SS 9-612-716-019-69-612-716-019-6
Southern pine #1 9-412-4 15-9 19-2 9-412-414-1117-9
Southern pine #2 9-212-114-8 17-2 8-811-313-515-8
Southern pine #3 7-49-5 11-1 13-2 6-98-710-112-1
Spruce-pine-fir SS 9-011-10 15-1 18-4 9-011-1015-117-9
Spruce-pine-fir #8-911-6 14-1 16-3 8-310-612-1014-10
Spruce-pine-fir #2 8-911-614-116-38-310-612-1014-10
Spruce-pine-fir #3 6-10 8-8 10-7 12-46-37-119-8 11-3
24Douglas fir-larch SS 9-011-1115-218-5 9-011-11 14-9 17-1
Douglas fir-larch #1 8-811-013-515-7 7-1110-012-3 14-3
Douglas fir-larch #2 8-110-312-714-7 7-59-511-613-4
Douglas fir-larch #3 6-27-99-611-0 5-77-1 8-8 10-1
Hem-fir SS 8-611-314-417-5 8-611-314-4 16-10a
Hem-fir #1 8-410-913-115-2 7-99-911-11 13-10
Hem-fir #2 7-1110-212-514-4 7-49-311-413-1
Hem-fir #3 6-2 7-9 9-6 11-0 5-7 7-1 8-8 10-1
Southern pine SS 8-1011-814-1118-18-1011-814-1118-1
Southern pine #1 8-811-514-717-5 8-811-3 13-4 15-11
Southern pine #2 8-611-013-115-5 7-910-012-014-0
Southern pine #3 6-78-59-1111-10 6-07-8 9-1 10-9
Spruce-pine-fir SS 8-411-014-017-0 8-411-013-8 15-11
Spruce-pine-fir #1 8-110-312-714-7 7-59-511-6 13-4
Spruce-pine-fir #2 8-110-312-714-77-59-511-613-4
Spruce-pine-fir #3 6-27-99-6 11-05-7 7-1 8-8 10-1
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
a. End bearing length shall be increased to 2 inches.
b. Dead load limits for townhouses in Seismic Design Category C and all structures in Seismic Design Categories D0, D1, and D2 shall be determined in accordance with Section R301.2.2.2.1.
Table R502.3.1(2) shall be used to determine the maximum allowable span of floor joists that support all other areas of the building, other than sleeping rooms and attics, provided that the design live load does not exceed 40 pounds per square foot (1.92 kPa) and the design dead load does not exceed 20 pounds per square foot (0.96 kPa).
Floor cantilever spans shall not exceed the nominal depth of the wood floor joist. Floor cantilevers constructed in accordance with Table R502.3.3(1) shall be permitted when supporting a light-frame bearing wall and roof only. Floor cantilevers supporting an exterior balcony are permitted to be constructed in accordance with Table R502.3.3(2)

TABLE R502.3.3(1)
CANTILEVER SPANS FOR FLOOR JOISTS SUPPORTING LIGHT-FRAME EXTERIOR BEARING WALL AND ROOF ONLYa, b, c, f, g, h
(Floor Live Load ≤ 40 psf, Roof Live Load ≤ 20 psf)

Member & SpacingMaximum Cantilever Span (Uplift Force at Backspan Support in Lbs.)d, e
Ground Snow Load
≤ 20 psf30 psf50 psf70 psf
Roof WidthRoof WidthRoof WidthRoof Width
24 ft32 ft40 ft24 ft32 ft40 ft24 ft32 ft40 ft24 ft32 ft40 ft
2 × 8 @ 12″20″(177)15″(227)18″(209)
2 × 10 @ 16″29″(228)21″(297)16″(364)26″(271)18″(354)20″(375)
2 × 10 @ 12″36″(166)26″(219)20″(270)34″(198)22″(263)16″(324)26″(277)19″(356)
2 × 12 @ 16″32″(287)25″(356)36″(263)29″(345)21″(428)29″(367)20″(484)23″(471)
2 × 12 @ 12″42″(209)31″(263)37″(253)27″(317)36″(271)27″(358)17″(447)31″(348)19″(462)
2 × 12 @ 8″48″(136)45″(169)48″(164)38″(206)40″(233)26″(294)36″(230)29″(304)18″(379)
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, hem-fir, southern pine and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be at least 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual backspan ratio provided (3/backspan ratio).
f. See Section R301.2.2.2.5, Item 1, for additional limitations on cantilevered floor joists for detached one- and two-family dwellings in Seismic Design Category D0, D1, or D2 and townhouses in Seismic Design Category C, D0, D1 or D2.
g. A full-depth rim joist shall be provided at the unsupported end of the cantilever joists. Solid blocking shall be provided at the supported end.
h. Linear interpolation shall be permitted for building widths and ground snow loads other than shown.

TABLE R502.3.3(2)
CANTILEVER SPANS FOR FLOOR JOISTS SUPPORTING EXTERIOR BALCONYa, b, e, f

Member SizeSpacingMaximum Cantilever Span
(Uplift Force at Backspan Support in lb)c, d
Ground Snow Load
≤ 30 psf50 psf70 psf
2 × 812″42″ (139)39″ (156)34″ (165)
2 × 816″36″ (151)34″ (171)29″ (180)
2 × 1012″61″ (164)57″ (189)49″ (201)
2 × 1016″53″ (180)49″ (208)42″ (220)
2 × 1024″43″ (212)40″ (241)34″ (255)
2 × 1216″72″ (228)67″ (260)57″ (268)
2 × 1224″58″ (279)54″ (319)47″ (330)
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
a. Spans are based on No. 2 Grade lumber of Douglas fir-larch, hem-fir, southern pine and spruce-pine-fir for repetitive (three or more) members.
b. Ratio of backspan to cantilever span shall be at least 2:1.
c. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
d. Uplift force is for a backspan to cantilever span ratio of 2:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 2 divided by the actual backspan ratio provided (2/backspan ratio).
e. A full-depth rim joist shall be provided at the unsupported end of the cantilever joists. Solid blocking shall be provided at the supported end.
f. Linear interpolation shall be permitted for ground snow loads other than shown.
Joists under parallel bearing partitions shall be of adequate size to support the load. Double joists, sized to adequately support the load, that are separated to permit the installation of piping or vents shall be full depth solid blocked with lumber not less than 2 inches (51 mm) in nominal thickness spaced not more than 4 feet (1219 mm) on center. Bearing partitions perpendicular to joists shall not be offset from supporting girders, walls or partitions more than the joist depth unless such joists are of sufficient size to carry the additional load.
The allowable spans of girders fabricated of dimension lumber shall not exceed the values set forth in Tables R502.5(1) and R502.5(2).

TABLE R502.5(1)
GIRDER SPANSa AND HEADER SPANSa FOR EXTERIOR BEARING WALLS
(Maximum spans for Douglas fir-larch, hem-fir, southern pine and spruce-pine-firb and required number of jack studs)

GIRDERS AND
HEADERS
SUPPORTING
SIZEGROUND SNOW LOAD (psf)e
305070
Building widthc (feet)
202836202836202836
SpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJd
Roof and ceiling2-2 × 43-613-212-1013-212-912-612-1012-612-31
2-2 × 65-514-814-214-814-113-824-213-823-32
2-2 × 86-1015-1125-425-1125-224-725-424-724-12
2-2 × 108-527-326-627-326-325-726-625-725-02
2-2 × 129-928-527-628-527-326-627-626-625-103
3-2 × 88-417-516-817-516-525-926-815-925-22
3-2 × 1010-619-128-229-127-1027-028-227-026-42
3-2 × 1212-2210-729-5210-729-228-229-528-227-42
4-2 × 89-218-417-818-417-516-817-816-815-112
4-2 × 1011-8110-619-5210-619-128-229-528-227-32
4-2 × 1214-1112-2210-11212-2210-729-5210-1129-528-52
Roof, ceiling
and one center-
bearing floor
2-2 × 43-112-912-512-912-512-212-712-312-01
2-2 × 64-614-013-724-113-723-323-923-322-112
2-2 × 85-925-024-625-224-624-124-924-223-92
2-2 × 107-026-225-626-425-625-025-925-124-73
2-2 × 128-127-126-527-426-525-936-825-1035-33
3-2 × 87-216-325-826-525-825-125-1125-224-82
3-2 × 108-927-826-1127-1126-1126-327-326-425-82
3-2 × 1210-228-1128-029-228-027-328-527-426-72
4-2 × 88-117-316-717-516-615-1126-1016-025-52
4-2 × 1010-118-1028-029-128-027-228-427-426-72
4-2 × 1211-9210-329-3210-729-328-429-828-627-72
Roof, ceiling
and one clear span floor
2-2 × 42-812-412-112-712-312-012-512-111-101
2-2 × 63-1113-523-023-1023-423-023-623-122-92
2-2 × 85-024-423-1024-1024-223-924-623-1123-62
2-2 × 106-125-324-825-1125-124-735-624-924-33
2-2 × 127-126-135-536-1025-1135-436-425-635-03
3-2 × 86-325-524-1026-125-324-825-724-1124-52
3-2 × 107-726-725-1127-526-525-926-1026-025-42
3-2 × 128-1027-826-1028-727-526-827-1126-1126-32
4-2 × 87-216-325-727-016-125-526-615-825-12
4-2 × 108-927-726-1028-727-526-727-1126-1126-22
4-2 × 1210-228-1027-1129-1128-727-829-228-027-22
Roof, ceiling
and two center-
bearing floors
2-2 × 42-712-312-012-612-211-1112-412-011-91
2-2 × 63-923-322-1123-823-222-1023-523-022-82
2-2 × 84-924-223-924-724-023-824-423-923-52
2-2 × 105-925-124-735-824-1124-535-324-734-23
2-2 × 126-825-1035-336-625-935-236-135-434-103
3-2 × 85-1125-224-825-925-124-725-524-924-32
3-2 × 107-326-425-827-126-225-726-725-925-32
3-2 × 128-527-426-728-227-226-537-826-926-13
4-2 × 86-1016-025-526-815-1025-326-325-624-112
4-2 × 108-427-426-728-227-226-527-726-826-02
4-2 × 129-828-627-829-528-327-528-1027-927-02
Roof, ceiling,
and two clear
span floors
2-2 × 4 2-1 1 1-8 1 1-6 2 2-0 1 1-8 1 1-5 2 2-0 1 1-8 1 1-5 2
2-2 × 6 3-1 2 2-8 2 2-4 2 3-0 2 2-7 2 2-3 2 2-11 2 2-7 2 2-3 2
2-2 × 8 3-10 2 3-4 2 3-0 3 3-10 2 3-4 2 2-11 3 3-9 2 3-3 2 2-11 3

(continued)

TABLE R502.5(1)—continued
GIRDER SPANSa AND HEADER SPANSa FOR EXTERIOR BEARING WALLS
(Maximum spans for Douglas fir-larch, hem-fir, southern pine and spruce-pine-firb and required number of jack studs)

GIRDERS AND
HEADERS
SUPPORTING
SIZEGROUND SNOW LOAD (psf)e
305070
Building widthc (feet)
202836202836202836
SpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJdSpanNJd
Roof, ceiling,
and two clear span floors
2-2 × 10 4-9 2 4-1 3 3-8 3 4-8 2 4-0 3 3-7 3 4-7 3 4-0 3 3-6 3
2-2 × 12 5-6 3 4-9 3 4-3 3 5-5 3 4-8 3 4-2 3 5-4 3 4-7 3 4-1 4
3-2 × 8 4-10 2 4-2 2 3-9 2 4-9 2 4-1 2 3-8 2 4-8 2 4-1 2 3-8 2
3-2 × 10 5-11 2 5-1 2 4-7 3 5-10 2 5-0 2 4-6 3 5-9 2 4-11 2 4-5 3
3-2 × 12 6-10 2 5-11 3 5-4 3 6-9 2 5-10 3 5-3 3 6-8 2 5-9 3 5-2 3
4-2 × 8 5-7 2 4-10 2 4-4 2 5-6 2 4-9 2 4-3 2 5-5 2 4-8 2 4-2 2
4-2 × 10 6-10 2 5-11 2 5-3 2 6-9 2 5-10 2 5-2 2 6-7 2 5-9 2 5-1 2
4-2 × 12 7-11 2 6-10 2 6-2 3 7-9 2 6-9 2 6-0 3 7-8 2 6-8 2 5-11 3
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
a. Spans are given in feet and inches.
b. Tabulated values assume #2 grade lumber.
c. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.
d. NJ - Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.
e. Use 30 psf ground snow load for cases in which ground snow load is less than 30 psf and the roof live load is equal to or less than 20 psf.

TABLE R502.5(2)
GIRDER SPANSa AND HEADER SPANSa FOR INTERIOR BEARING WALLS
(Maximum spans for Douglas fir-larch, hem-fir, southern pine and spruce-pine-firb and required number of jack studs)

HEADERS AND
GIRDERS
SUPPORTING
SIZEBUILDING Widthc (feet)
202836
SpanNJdSpanNJdSpanNJd
One floor only2-2 × 43-112-812-51
2-2 × 64-613-1113-61
2-2 × 85-915-024-52
2-2 × 107-026-125-52
2-2 × 128-127-026-32
3-2 × 87-216-315-72
3-2 × 108-917-726-92
3-2 × 1210-228-1027-102
4-2 × 89-017-816-91
4-2 × 1010-118-917-102
4-2 × 1211-9110-229-12
Two floors2-2 × 42-211-1011-71
2-2 × 63-222-922-52
2-2 × 84-123-623-22
2-2 × 104-1124-323-103
2-2 × 125-925-034-53
3-2 × 85-124-523-112
3-2 × 106-225-424-102
3-2 × 127-226-325-73
4-2 × 86-115-324-82
4-2 × 107-226-225-62
4-2 × 128-427-226-52
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. Spans are given in feet and inches.
b. Tabulated values assume #2 grade lumber.
c. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.
d. NJ - Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.
The ends of each joist, beam or girder shall have not less than 1.5 inches (38 mm) of bearing on wood or metal and not less than 3 inches (76 mm) on masonry or concrete except where supported on a 1-inch by 4-inch (25.4 mm by 102 mm) ribbon strip and nailed to the adjacent stud or by the use of approved joist hangers. The bearing on masonry or concrete shall be direct, or a sill plate of 2-inch-minimum (51 mm) nominal thickness shall be provided under the joist, beam or girder. The sill plate shall provide a minimum nominal bearing area of 48 square inches (30 865 square mm).
Joists framing from opposite sides over a bearing support shall lap a minimum of 3 inches (76 mm) and shall be nailed together with a minimum three 10d face nails. A wood or metal splice with strength equal to or greater than that provided by the nailed lap is permitted.
Joists framing into the side of a wood girder shall be supported by approved framing anchors or on ledger strips not less than nominal 2 inches by 2 inches (51 mm by 51 mm).
Joists shall be supported laterally at the ends by full-depth solid blocking not less than 2 inches (51 mm) nominal in thickness; or by attachment to a full-depth header, band or rim joist, or to an adjoining stud or shall be otherwise provided with lateral support to prevent rotation.
Exceptions:
1. Trusses, structural composite lumber, structural glued-laminated members and I-joists shall be supported laterally as required by the manufacturer's recommendations.
2. In Seismic Design Categories D0, D1 and D2, lateral restraint shall also be provided at each intermediate support.
Joists exceeding a nominal 2 inches by 12 inches (51 mm by 305 mm) shall be supported laterally by solid blocking, diagonal bridging (wood or metal), or a continuous 1 inch by 3 inch (25.4 mm by 76 mm) strip nailed across the bottom of joists perpendicular to joists at intervals not exceeding 8 feet (2438 mm).

Exception: Trusses, structural composite lumber, structural glued-laminated members and I-joists shall be supported laterally as required by the manufacturer's recommendations.

Structural floor members shall not be cut, bored or notched in excess of the limitations specified in this section. See Figure R502.8.
For SI: 1 inch = 25.4 mm.

FIGURE R502.8
CUTTING, NOTCHING AND DRILLING

Notches in solid lumber joists, rafters and beams shall not exceed one-sixth of the depth of the member, shall not be longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Notches at the ends of the member shall not exceed one-fourth the depth of the member. The tension side of members 4 inches (102 mm) or greater in nominal thickness shall not be notched except at the ends of the members. The diameter of holes bored or cut into members shall not exceed one-third the depth of the member. Holes shall not be closer than 2 inches (51 mm) to the top or bottom of the member, or to any other hole located in the member. Where the member is also notched, the hole shall not be closer than 2 inches (51 mm) to the notch.
Cuts, notches and holes bored in trusses, structural composite lumber, structural glue-laminated members or I-joists are prohibited except where permitted by the manufacturer's recommendations or where the effects of such alterations are specifically considered in the design of the member by a registered design professional.
Floor framing shall be nailed in accordance with Table R602.3(1). Where posts and beam or girder construction is used to support floor framing, positive connections shall be provided to ensure against uplift and lateral displacement.
Openings in floor framing shall be framed with a header and trimmer joists. When the header joist span does not exceed 4 feet (1219 mm), the header joist may be a single member the same size as the floor joist. Single trimmer joists may be used to carry a single header joist that is located within 3 feet (914 mm) of the trimmer joist bearing. When the header joist span exceeds 4 feet (1219 mm), the trimmer joists and the header joist shall be doubled and of sufficient cross section to support the floor joists framing into the header. Approved hangers shall be used for the header joist to trimmer joist connections when the header joist span exceeds 6 feet (1829 mm). Tail joists over 12 feet (3658 mm) long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches by 2 inches (51 mm by 51 mm).
Wood trusses shall be designed in accordance with approved engineering practice. The design and manufacture of metal plate connected wood trusses shall comply with ANSI/TPI 1. The truss design drawings shall be prepared by a registered professional where required by the statutes of the jurisdiction in which the project is to be constructed in accordance with Section R106.1.
Trusses shall be braced to prevent rotation and provide lateral stability in accordance with the requirements specified in the construction documents for the building and on the individual truss design drawings. In the absence of specific bracing requirements, trusses shall be braced in accordance with accepted industry practices, such as, the SBCA Building Component Safety Information (BCSI) Guide to Good Practice for Handling, Installing & Bracing of Metal Plate Connected Wood Trusses.
Truss members and components shall not be cut, notched, spliced or otherwise altered in any way without the approval of a registered design professional. Alterations resulting in the addition of load (e.g., HVAC equipment, water heater, etc.), that exceed the design load for the truss, shall not be permitted without verification that the truss is capable of supporting the additional loading.
Truss design drawings, prepared in compliance with Section R502.11.1, shall be submitted to the building official and approved prior to installation. Truss design drawings shall be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the information specified below:
1. Slope or depth, span and spacing.
2. Location of all joints.
3. Required bearing widths.
4. Design loads as applicable:
4.1. Top chord live load;
4.2. Top chord dead load;
4.3. Bottom chord live load;
4.4. Bottom chord dead load;
4.5. Concentrated loads and their points of application; and
4.6. Controlling wind and earthquake loads.
5. Adjustments to lumber and joint connector design values for conditions of use.
6. Each reaction force and direction.
7. Joint connector type and description, e.g., size, thickness or gauge, and the dimensioned location of each joint connector except where symmetrically located relative to the joint interface.
8. Lumber size, species and grade for each member.
9. Connection requirements for:
9.1. Truss-to-girder-truss;
9.2. Truss ply-to-ply; and
9.3. Field splices.
10. Calculated deflection ratio and/or maximum description for live and total load.
11. Maximum axial compression forces in the truss members to enable the building designer to design the size, connections and anchorage of the permanent continuous lateral bracing. Forces shall be shown on the truss drawing or on supplemental documents.
12. Required permanent truss member bracing location.
Draftstopping shall be provided in accordance with Section R302.12.
Fireblocking shall be provided in accordance with Section R302.11.
Maximum allowable spans for lumber used as floor sheathing shall conform to Tables R503.1, R503.2.1.1(1) and R503.2.1.1(2).

TABLE R503.1
MINIMUM THICKNESS OF LUMBER FLOOR SHEATHING

JOIST OR BEAM
SPACING (inches)
MINIMUM NET THICKNESS
Perpendicular to joistDiagonal to joist
2411/163/4
165/85/8
48a11/2 T & GN/A
54b
60c
For SI: 1 inch = 25.4 mm, 1 pound per square inch = 6.895 kPa.
N/A = Not applicable.
a. For this support spacing, lumber sheathing shall have a minimum Fb of 675 and minimum E of 1,100,000 (see AF&PA/NDS).
b. For this support spacing, lumber sheathing shall have a minimum Fb of 765 and minimum E of 1,400,000 (see AF&PA/NDS).
c. For this support spacing, lumber sheathing shall have a minimum Fb of 855 and minimum E of 1,700,000 (see AF&PA/NDS).
End joints in lumber used as subflooring shall occur over supports unless end-matched lumber is used, in which case each piece shall bear on at least two joists. Subflooring may be omitted when joist spacing does not exceed 16 inches (406 mm) and a 1-inch (25.4 mm) nominal tongue-and-groove wood strip flooring is applied perpendicular to the joists.
Wood structural panel sheathing used for structural purposes shall conform to DOC PS 1, DOC PS 2 or, when manufactured in Canada, CSA O437 or CSA O325. All panels shall be identified for grade, bond classification, and Performance Category by a grade mark or certificate of inspection issued by an approved agency. The Performance Category value shall be used as the “nominal panel thickness” or “panel thickness” whenever referenced in this code.
Where used as subflooring or combination subfloor underlayment, wood structural panels shall be of one of the grades specified in Table R503.2.1.1(1). When sanded plywood is used as combination subfloor underlayment, the grade, bond classification, and Performance Category shall be as specified in Table R503.2.1.1(2).

TABLE R503.2.1.1(1)
ALLOWABLE SPANS AND LOADS FOR WOOD STRUCTURAL PANELS FOR ROOF AND
SUBFLOOR SHEATHING AND COMBINATION SUBFLOOR UNDERLAYMENTa, b, c

SPAN RATINGMINIMUM NOMINAL
PANEL THICKNESS
(inch)
ALLOWABLE LIVE LOAD
(psf)h, I
MAXIMUM SPAN
(inches)
LOAD (pounds per square
foot, at maximum span)
MAXIMUM SPAN
(inches)
SPAN
@ 16″ o.c.
SPAN
@ 24″ o.c.
With edge
supportd
Without edge
support
Total loadLive load
SheathingeRooffSubfloorj
16/03/830161640300
20/03/850202040300
24/03/8100302420g40300
24/167/16100402424504016
32/1615/32, 1/2180703228403016h
40/2019/32, 5/83051304032403020h, i
48/2423/32, 3/41754836453524
60/327/83056048453532
Underlayment, C-C plugged, single flooreRooffCombination subfloor underlaymentk
16 o.c.19/32, 5/8100402424504016i
20 o.c.19/32, 5/8150603232403020i, j
24 o.c.23/32, 3/42401004836352524
32 o.c.7/81854840504032
48 o.c.13/32, 11/82906048504048
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
a. The allowable total loads were determined using a dead load of 10 psf. If the dead load exceeds 10 psf, then the live load shall be reduced accordingly.
b. Panels continuous over two or more spans with long dimension (strength axis) perpendicular to supports. Spans shall be limited to values shown because of possible effect of concentrated loads.
c. Applies to panels 24 inches or wider.
d. Lumber blocking, panel edge clips (one midway between each support, except two equally spaced between supports when span is 48 inches), tongue-and-groove panel edges, or other approved type of edge support.
e. Includes Structural I panels in these grades.
f. Uniform load deflection limitation: 1/180 of span under live load plus dead load, 1/240 of span under live load only.
g. Maximum span 24 inches for 15/32-and 1/2-inch panels.
h. Maximum span 24 inches where 3/4-inch wood finish flooring is installed at right angles to joists.
i. Maximum span 24 inches where 1.5 inches of lightweight concrete or approved cellular concrete is placed over the subfloor.
j. Unsupported edges shall have tongue-and-groove joints or shall be supported with blocking unless minimum nominal 1/4-inch thick underlayment with end and edge joints offset at least 2 inches or 1.5 inches of lightweight concrete or approved cellular concrete is placed over the subfloor, or 3/4-inch wood finish flooring is installed at right angles to the supports. Allowable uniform live load at maximum span, based on deflection of 1/360 of span, is 100 psf.
k. Unsupported edges shall have tongue-and-groove joints or shall be supported by blocking unless nominal 1/4-inch-thick underlayment with end and edge joints offset at least 2 inches or 3/4-inch wood finish flooring is installed at right angles to the supports. Allowable uniform live load at maximum span, based on deflection of 1/360 of span, is 100 psf, except panels with a span rating of 48 on center are limited to 65 psf total uniform load at maximum span.
l. Allowable live load values at spans of 16″ o.c. and 24″ o.c taken from reference standard APA E30, APA Engineered Wood Construction Guide. Refer to reference standard for allowable spans not listed in the table.

TABLE R503.2.1.1(2)
ALLOWABLE SPANS FOR SANDED
PLYWOOD COMBINATION SUBFLOOR UNDERLAYMENTa

IDENTIFICATIONSPACING OF JOISTS (inches)
162024
Species groupb
11/25/83/4
2, 35/83/47/8
43/47/81
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
a. Plywood continuous over two or more spans and face grain perpendicular to supports. Unsupported edges shall be tongue-and-groove or blocked except where nominal 1/4-inch-thick underlayment or 3/4-inch wood finish floor is used. Allowable uniform live load at maximum span based on deflection of 1/360 of span is 100 psf.
b. Applicable to all grades of sanded exterior-type plywood.
The maximum allowable span for wood structural panels used as subfloor or combination subfloor underlayment shall be as set forth in Table R503.2.1.1(1), or APA E30. The maximum span for sanded plywood combination subfloor underlayment shall be as set forth in Table R503.2.1.1(2).
Wood structural panels used as subfloor or combination subfloor underlayment shall be attached to wood framing in accordance with Table R602.3(1) and shall be attached to cold-formed steel framing in accordance with Table R505.3.1(2).
Particleboard shall conform to ANSI A208.1 and shall be so identified by a grade mark or certificate of inspection issued by an approved agency.
Particleboard floor underlayment shall conform to Type PBU and shall not be less than 1/4 inch (6.4 mm) in thickness.
Particleboard underlayment shall be installed in accordance with the recommendations of the manufacturer and attached to framing in accordance with Table R602.3(1).
Pressure preservatively treated-wood basement floors and floors on ground shall be designed to withstand axial forces and bending moments resulting from lateral soil pressures at the base of the exterior walls and floor live and dead loads. Floor framing shall be designed to meet joist deflection requirements in accordance with Section R301.
Unless special provision is made to resist sliding caused by unbalanced lateral soil loads, wood basement floors shall be limited to applications where the differential depth of fill on opposite exterior foundation walls is 2 feet (610 mm) or less.
Joists in wood basement floors shall bear tightly against the narrow face of studs in the foundation wall or directly against a band joist that bears on the studs. Plywood subfloor shall be continuous over lapped joists or over butt joints between in-line joists. Sufficient blocking shall be provided between joists to transfer lateral forces at the base of the end walls into the floor system.
Where required, resistance to uplift or restraint against buckling shall be provided by interior bearing walls or properly designed stub walls anchored in the supporting soil below.
The area within the foundation walls shall have all vegetation, topsoil and foreign material removed, and any fill material that is added shall be free of vegetation and foreign material. The fill shall be compacted to assure uniform support of the pressure preservatively treated-wood floor sleepers.
A minimum 4-inch-thick (102 mm) granular base of gravel having a maximum size of 3/4 inch (19.1 mm) or crushed stone having a maximum size of 1/2 inch (12.7 mm) shall be placed over the compacted earth.
Polyethylene sheeting of minimum 6-mil (0.15 mm) thickness shall be placed over the granular base. Joints shall be lapped 6 inches (152 mm) and left unsealed. The polyethylene membrane shall be placed over the pressure preservatively treated-wood sleepers and shall not extend beneath the footing plates of the exterior walls.
All framing materials, including sleepers, joists, blocking and plywood subflooring, shall be pressure-preservative treated and dried after treatment in accordance with AWPA U1 (Commodity Specification A, Use Category 4B and Section 5.2), and shall bear the label of an accredited agency.
Elements shall be straight and free of any defects that would significantly affect structural performance. Cold-formed steel floor framing members shall comply with the requirements of this section.
The provisions of this section shall control the construction of cold-formed steel floor framing for buildings not greater than 60 feet (18 288 mm) in length perpendicular to the joist span, not greater than 40 feet (12 192 mm) in width parallel to the joist span, and less than or equal to three stories above grade plane. Cold-formed steel floor framing constructed in accordance with the provisions of this section shall be limited to sites subjected to a maximum design wind speed of 110 miles per hour (49 m/s), Exposure B or C, and a maximum ground snow load of 70 pounds per square foot (3.35 kPa).
When supported by cold-formed steel framed walls in accordance with Section R603, cold-formed steel floor framing shall be constructed with floor joists located in-line with load-bearing studs located below the joists in accordance with Figure R505.1.2 and the tolerances specified as follows:
1. The maximum tolerance shall be 3/4 inch (19.1 mm) between the centerline of the horizontal framing member and the centerline of the vertical framing member.
2. Where the centerline of the horizontal framing member and bearing stiffener are located to one side of the centerline of the vertical framing member, the maximum tolerance shall be 1/8 inch (3 mm) between the web of the horizontal framing member and the edge of the vertical framing member.
For SI: 1 inch = 25.4 mm.

FIGURE R505.1.2
IN-LINE FRAMING

Cold-formed steel trusses shall be designed, braced and installed in accordance with AISI S100, Section D4. In the absence of specific bracing requirements, trusses shall be braced in accordance with accepted industry practices, such as the SBCA Cold-Formed Steel Building Component Safety Information (CFSBCSI), Guide to Good Practice for Handling, Installing & Bracing of Cold-Formed Steel Trusses. Truss members shall not be notched, cut or altered in any manner without an approved design.
Load-bearing cold-formed steel floor framing members shall comply with Figure R505.2(1) and with the dimensional and minimum thickness requirements specified in Tables R505.2(1) and R505.2(2). Tracks shall comply with Figure R505.2(2) and shall have a minimum flange width of 11/4 inches (32 mm).

FIGURE R505.2(1)
C-SHAPED SECTION

FIGURE R505.2(2)
TRACK SECTION

TABLE R505.2(1)
COLD-FORMED STEEL JOIST SIZES

MEMBER DESIGNATIONaWEB DEPTH
(inches)
MINIMUM FLANGE WIDTH (inches)MAXIMUM FLANGE WIDTH (inches)MINIMUM LIP SIZE
(inches)
550S162-t5.51.62520.5
800S162-t81.62520.5
1000S162-t101.62520.5
1200S162-t121.62520.5
For SI: 1 inch = 25.4 mm, 1 mil = 0.0254 mm.
a. The member designation is defined by the first number representing the member depth in 0.01 inch, the letter “S” representing a stud or joist member, the second number representing the flange width in 0.01 inch, and the letter “t” shall be a number representing the minimum base metal thickness in mils [See Table R505.2(2)].

TABLE R505.2(2)
MINIMUM THICKNESS OF COLD-FORMED STEEL MEMBERS

DESIGNATION THICKNESS
(mils)
MINIMUM BASE STEEL THICKNESS
(inches)
330.0329
430.0428
540.0538
680.0677
970.0966
For SI: inch = 25.4 mm, 1 mil = 0.0254 mm.
Load-bearing cold-formed steel framing members shall be cold formed to shape from structural quality sheet steel complying with the requirements of one of the following:
1. ASTM A 653: Grades 33 and 50 (Class 1 and 3).
2. ASTM A 792: Grades 33 and 50A.
3. ASTM A 1003: Structural Grades 33 Type H and 50 Type H.
Load-bearing cold-formed steel framing members shall have a legible label, stencil, stamp or embossment with the following information as a minimum:
1. Manufacturer's identification.
2. Minimum base steel thickness in inches (mm).
3. Minimum coating designation.
4. Minimum yield strength, in kips per square inch (ksi) (MPa).
Load-bearing cold-formed steel framing shall have a metallic coating complying with ASTM A 1003 and one of the following:
1. A minimum of G 60 in accordance with ASTM A 653.
2. A minimum of AZ 50 in accordance with ASTM A 792.
Screws for steel-to-steel connections shall be installed with a minimum edge distance and center-to-center spacing of 1/2 inch (12.7 mm), shall be self-drilling tapping, and shall conform to ASTM C 1513. Floor sheathing shall be attached to cold-formed steel joists with minimum No. 8 self-drilling tapping screws that conform to ASTM C 1513. Screws attaching floor-sheathing to cold-formed steel joists shall have a minimum head diameter of 0.292 inch (7.4 mm) with countersunk heads and shall be installed with a minimum edge distance of 3/8 inch (9.5 mm). Gypsum board ceilings shall be attached to cold-formed steel joists with minimum No. 6 screws conforming to ASTM C 954 or ASTM C 1513 with a bugle head style and shall be installed in accordance with Section R702. For all connections, screws shall extend through the steel a minimum of three exposed threads. All fasteners shall have rust inhibitive coating suitable for the installation in which they are being used, or be manufactured from material not susceptible to corrosion.

Where No. 8 screws are specified in a steel-to-steel connection, the required number of screws in the connection is permitted to be reduced in accordance with the reduction factors in Table R505.2.4 when larger screws are used or when one of the sheets of steel being connected is thicker than 33 mils (0.84 mm). When applying the reduction factor, the resulting number of screws shall be rounded up.

TABLE R505.2.4
SCREW SUBSTITUTION FACTOR

SCREW SIZETHINNEST CONNECTED STEEL SHEET (mils)
3343
#81.00.67
#100.930.62
#120.860.56
For SI: 1 mil = 0.0254 mm.
Web holes, web hole reinforcing, and web hole patching shall be in accordance with this section.
Web holes in floor joists shall comply with all of the following conditions:
1. Holes shall conform to Figure R505.2.5.1;
2. Holes shall be permitted only along the centerline of the web of the framing member;
3. Holes shall have a center-to-center spacing of not less than 24 inches (610 mm);
4. Holes shall have a web hole width not greater than 0.5 times the member depth, or 21/2 inches (64.5 mm);
5. Holes shall have a web hole length not exceeding 41/2 inches (114 mm); and
6. Holes shall have a minimum distance between the edge of the bearing surface and the edge of the web hole of not less than 10 inches (254 mm).

Framing members with web holes not conforming to the above requirements shall be reinforced in accordance with Section R505.2.5.2, patched in accordance with Section R505.2.5.3 or designed in accordance with accepted engineering practices.

For SI: 1 inch = 25.4 mm.

FIGURE R505.2.5.1
FLOOR JOIST WEB HOLES

Reinforcement of web holes in floor joists not conforming to the requirements of Section R505.2.5.1 shall be permitted if the hole is located fully within the center 40 percent of the span and the depth and length of the hole does not exceed 65 percent of the flat width of the web. The reinforcing shall be a steel plate or C-shape section with a hole that does not exceed the web hole size limitations of Section R505.2.5.1 for the member being reinforced. The steel reinforcing shall be the same thickness as the receiving member and shall extend at least 1 inch (25.4 mm) beyond all edges of the hole. The steel reinforcing shall be fastened to the web of the receiving member with No. 8 screws spaced no more than 1 inch (25.4 mm) center-to-center along the edges of the patch with minimum edge distance of 1/2 inch (12.7 mm).
Patching of web holes in floor joists not conforming to the requirements in Section R505.2.5.1 shall be permitted in accordance with either of the following methods:
1. Framing members shall be replaced or designed in accordance with accepted engineering practices where web holes exceed the following size limits:
1.1. The depth of the hole, measured across the web, exceeds 70 percent of the flat width of the web; or
1.2. The length of the hole measured along the web, exceeds 10 inches (254 mm) or the depth of the web, whichever is greater.
2. Web holes not exceeding the dimensional requirements in Section R505.2.5.3, Item 1, shall be patched with a solid steel plate, stud section, or track section in accordance with Figure R505.2.5.3. The steel patch shall, as a minimum, be of the same thickness as the receiving member and shall extend at least 1 inch (25 mm) beyond all edges of the hole. The steel patch shall be fastened to the web of the receiving member with No. 8 screws spaced no more than 1 inch (25 mm) center-to-center along the edges of the patch with minimum edge distance of 1/2 inch (13 mm).
For SI: 1 inch = 25.4 mm.

FIGURE R505.2.5.3
WEB HOLE PATCH

Cold-formed steel floors shall be constructed in accordance with this section.
Cold-formed steel framed floors shall be anchored to foundations, wood sills or load-bearing walls in accordance with Table R505.3.1(1) and Figure R505.3.1(1), R505.3.1(2), R505.3.1(3), R505.3.1(4), R505.3.1(5) or R505.3.1(6). Anchor bolts shall be located not more than 12 inches (305 mm) from corners or the termination of bottom tracks. Continuous cold-formed steel joists supported by interior load-bearing walls shall be constructed in accordance with Figure R505.3.1(7). Lapped cold-formed steel joists shall be constructed in accordance with Figure R505.3.1(8). End floor joists constructed on foundation walls parallel to the joist span shall be doubled unless a C-shaped bearing stiffener, sized in accordance with Section R505.3.4, is installed web-to-web with the floor joist beneath each supported wall stud, as shown in Figure R505.3.1(9). Fastening of cold-formed steel joists to other framing members shall be in accordance with Section R505.2.4 and Table R505.3.1(2).

TABLE R505.3.1(1)
FLOOR TO FOUNDATION OR BEARING WALL CONNECTION REQUIREMENTSa, b

FRAMING CONDITIONBASIC WIND SPEED (mph) AND EXPOSURE
85 mph Exposure C or
less than 110 mph Exposure B
Less than 110 mph Exposure C
Floor joist to wall track of exterior wall per Figure R505.3.1(1)2-No. 8 screws3-No. 8 screws
Rim track or end joist to load-bearing wall top track per Figure R505.3.1(1)1-No. 8 screw at 24 inches o.c.1-No. 8 screw at 24 inches o.c.
Rim track or end joist to wood sill per Figure R505.3.1(2)Steel plate spaced at 4 feet o.c. with 4-No. 8 screws and 4-10d or 6-8d common nailsSteel plate spaced at 2 feet o.c. with 4-No. 8 screws and 4-10d or 6-8d common nails
Rim track or end joist to foundation per Figure R505.3.1(3)1/2 inch minimum diameter anchor bolt and clip angle spaced at 6 feet o.c. with 8-No. 8 screws1/2 inch minimum diameter anchor bolt and clip angle spaced at 4 feet o.c. with 8-No. 8 screws
Cantilevered joist to foundation per Figure R505.3.1(4)1/2 inch minimum diameter anchor bolt and clip angle spaced at 6 feet o.c. with 8-No. 8 screws1/2 inch minimum diameter anchor bolt and clip angle spaced at 4 feet o.c. with 8-No. 8 screws
Cantilevered joist to wood sill per
Figure R505.3.1(5)
Steel plate spaced at 4 feet o.c. with 4-No. 8 screws and 4-10d or 6-8d common nailsSteel plate spaced at 2 feet o.c. with 4-No. 8 screws and 4-10d or 6-8d common nails
Cantilevered joist to exterior load-bearing wall track per Figure R505.3.1(6)2-No. 8 screws3-No. 8 screws
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s, 1 foot = 304.8 mm.
a. Anchor bolts are to be located not more than 12 inches from corners or the termination of bottom tracks (e.g., at door openings or corners). Bolts extend a minimum of 15 inches into masonry or 7 inches into concrete. Anchor bolts connecting cold-formed steel framing to the foundation structure are to be installed so that the distance from the center of the bolt hole to the edge of the connected member is not less than one and one-half bolt diameters.
b. All screw sizes shown are minimum.
For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm.

FIGURE 505.3.1(1)
FLOOR TO EXTERIOR LOAD-BEARING WALL STUD CONNECTION

TABLE R505.3.1(2)
FLOOR FASTENING SCHEDULEa

DESCRIPTION OF BUILDING ELEMENTSNUMBER AND SIZE OF FASTENERSSPACING OF FASTENERS
Floor joist to track of an interior load-bearing wall per Figures R505.3.1(7) and R505.3.1(8) 2 No. 8 screwsEach joist
Floor joist to track at end of joist2 No. 8 screwsOne per flange or two per bearing stiffener
Subfloor to floor joistsNo. 8 screws6 in. o.c. on edges and 12 in. o.c. at intermediate supports
For SI: 1 inch = 25.4 mm.
a. All screw sizes shown are minimum.
For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm.

FIGURE R505.3.1(2)
FLOOR TO WOOD SILL CONNECTION

For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm.

FIGURE R505.3.1(3)
FLOOR TO FOUNDATION CONNECTION

For SI: 1 mil = 0.0254 mm.

FIGURE R505.3.1(4)
CANTILEVERED FLOOR TO FOUNDATION CONNECTION

For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm.

FIGURE R505.3.1(5)
CANTILEVERED FLOOR TO WOOD SILL CONNECTION

For SI: 1 mil = 0.0254 mm.

FIGURE R505.3.1(6)
CANTILEVERED FLOOR TO EXTERIOR LOAD-BEARING WALL CONNECTION

For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm.

FIGURE R505.3.1(7)
CONTINUOUS SPAN JOIST SUPPORTED ON INTERIOR LOAD-BEARING WALL

For SI: 1 inch = 25.4 mm.

FIGURE R505.3.1(8)
LAPPED JOISTS SUPPORTED ON INTERIOR LOAD-BEARING WALL

FIGURE R505.3.1(9)
BEARING STIFFENERS FOR END JOISTS

Floor joist size and thickness shall be determined in accordance with the limits set forth in Table R505.3.2(1) for single spans, and Tables R505.3.2(2) and R505.3.2(3) for multiple spans. When continuous joist members are used, the interior bearing supports shall be located within 2 feet (610 mm) of mid-span of the cold-formed steel joists, and the individual spans shall not exceed the spans in Table R505.3.2(2) or R505.3.2(3), as applicable. Floor joists shall have a bearing support length of not less than 11/2 inches (38 mm) for exterior wall supports and 31/2 inches (89 mm) for interior wall supports. Tracks shall be a minimum of 33 mils (0.84 mm) thick except when used as part of a floor header or trimmer in accordance with Section R505.3.8. Bearing stiffeners shall be installed in accordance with Section R505.3.4.

TABLE R505.3.2(1)
ALLOWABLE SPANS FOR COLD-FORMED STEEL JOISTS—SINGLE SPANSa, b, c, d 33 ksi STEEL

JOIST
DESIGNATION
30 PSF LIVE LOAD40 PSF LIVE LOAD
Spacing (inches)Spacing (inches)
121619.224121619.224
550S162-3311′-7″10′-7″9′-6″8′-6″10′-7″9′-3″8′-6″7′-6″
550S162-4312′-8″11′-6″10′-10″10′-2″11′-6″10′-5″9′-10″9′-1″
550S162-5413′-7″12′-4″11′-7″10′-9″12′-4″11′-2″10′-6″9′-9″
550S162-6814′-7″13′-3″12′-6″11′-7″13′-3″12′-0″11′-4″10′-6″
550S162-9716′-2″14′-9″13′-10″12′-10″14′-9″13′-4″12′-7″11′-8″
800S162-3315′-8″13′-11″12′-9″11′-5″14′-3″12′-5″11′-3″9′-0″
800S162-4317′-1″15′-6″14′-7″13′-7″15′-6″14′-1″13′-3″12′-4″
800S162-5418′-4″16′-8″15′-8″14′-7″16′-8″15′-2″14′-3″13′-3″
800S162-6819′-9″17′-11″16′-10″15′-8″17′-11″16′-3″15′-4″14′-2″
800S162-9722′-0″20′-0″16′-10″17′-5″20′-0″18′-2″17′-1″15′-10″
1000S162-4320′-6″18′-8″17′-6″15′-8″18′-8″16′-11″15′-6″13′-11″
1000S162-5422′-1″20′-0″18′-10″17′-6″20′-0″18′-2″17′-2″15′-11″
1000S162-6823′-9″21′-7″20′-3″18′-10″21′-7″19′-7″18′-5″17′-1″
1000S162-9726′-6″24′-1″22′-8″21′-0″24′-1″21′-10″20′-7″19′-1″
1200S162-4323′-9″20′-10″19′-0″16′-8″21′-5″18′-6″16′-6″13′-2″
1200S162-5425′-9″23′-4″22′-0″20′-1″23′-4″21′-3″20′-0″17′-10″
1200S162-6827′-8″25′-1″23′-8″21′-11″25′-1″22′-10″21′-6″21′-1″
1200S162-9730′-11″28′-1″26′-5″24′-6″28′-1″25′-6″24′-0″22′-3″
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Deflection criteria: L/480 for live loads, L/240 for total loads.
b. Floor dead load = 10 psf.
c. Table provides the maximum clear span in feet and inches.
d. Bearing stiffeners are to be installed at all support points and concentrated loads.

TABLE R505.3.2(2)
ALLOWABLE SPANS FOR COLD-FORMED STEEL JOISTS—MULTIPLE SPANSa, b, c, d, e, f 33 ksi STEEL

JOIST
DESIGNATION
30 PSF LIVE LOAD40 PSF LIVE LOAD
Spacing (inches)Spacing (inches)
121619.224121619.224
550S162-3312′-1″10′-5″9′-6″8′-6″10′-9″9′-3″8′-6″7′-6″
550S162-4314′-5″12′-5″11′-4″10′-2″12′-9″11′-11″10′-1″9′-0″
550S162-5416′-3″14′-1″12′-10″11′-6″14′-5″12′-6″11′-5″10′-2″
550S162-6819′-7″17′-9″16′-9″15′-6″17′-9″16′-2″15′-2″14′-1″
550S162-9721′-9″19′-9″18′-7″17′-3″19′-9″17′-11″16′-10″15′-4″
800S162-3314′-8″11′-10″10′-4″8′-8″12′-4″9′-11″8′-7″7′-2″
800S162-4320′-0″17′-4″15′-9″14′-1″17′-9″15′-4″14′-0″12′-0″
800S162-5423′-7″20′-5″18′-8″16′-8″21′-0″18′-2″16′-7″14′-10″
800S162-6826′-5″23′-1″21′-0″18′-10″23′-8″20′-6″18′-8″16′-9″
800S162-9729′-6″26′-10″25′-3″22′-8″26′-10″24′-4″22′-6″20′-2″
1000S162-4322′-2″18′-3″16′-0″13′-7″18′-11″15′-5″13′-6″11′-5″
1000S162-5426′-2″22′-8″20′-8″18′-6″23′-3″20′-2″18′-5″16′-5″
1000S162-6831′-5″27′-2″24′-10″22′-2″27′-11″24′-2″22′-1″19′-9″
1000S162-9735′-6″32′-3″29′-11″26′-9″32′-3″29′-2″26′-7″23′-9″
1200S162-4321′-8″17′-6″15′-3″12′-10″18′-3″14′-8″12′-8″10′-6″
1200S162-5428′-5″24′-8″22′-6″19′-6″25′-3″21′-11″19′-4″16′-6″
1200S162-6833′-7″29′-1″26′-6″23′-9″29′-10″25′-10″23′-7″21′-1″
1200S162-9741′-5″37′-8″34′-6″30′-10″37′-8″33′-6″30′-7″27′-5″
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Deflection criteria: L/480 for live loads, L/240 for total loads.
b. Floor dead load = 10 psf.
c. Table provides the maximum clear span in feet and inches to either side of the interior support.
d. Interior bearing supports for multiple span joists consist of structural (bearing) walls or beams.
e. Bearing stiffeners are to be installed at all support points and concentrated loads.
f. Interior supports shall be located within 2 feet of mid-span provided that each of the resulting spans does not exceed the appropriate maximum span shown in the table above.

TABLE R505.3.2(3)
ALLOWABLE SPANS FOR COLD-FORMED STEEL JOISTS—MULTIPLE SPANSa, b, c, d, e, f 50 ksi STEEL

JOIST
DESIGNATION
30 PSF LIVE LOAD40 PSF LIVE LOAD
Spacing (inches)Spacing (inches)
121619.224121619.224
550S162-3313′-11″12′-0″11′-0″9′-3″12′-3″10′-8″9′-7″8′-4″
550S162-4316′-3″14′-1″12′-10″11′-6″14′-6″12′-6″11′-5″10′-3″
550S162-5418′-2″16′-6″15′-4″13′-8″16′-6″14′-11″13′-7″12′-2″
550S162-6819′-6″17′-9″16′-8″15′-6″17′-9″16′-1″15′-2″14′-0″
550S162-9721′-9″19′-9″18′-6″17′-2″19′-8″17′-10″16′-8″15′-8″
800S162-3315′-6″12′-6″10′-10″9′-1″13′-0″10′-5″8′-11″6′-9″
800S162-4322′-0″19′-1″17′-5″15′-0″19′-7″16′-11″14′-10″12′-8″
800S162-5424′-6″22′-4″20′-6″17′-11″22′-5″19′-9″17′-11″15′-10″
800S162-6826′-6″24′-1″22′-8″21′-0″24′-1″21′-10″20′-7″19′-2″
800S162-9729′-9″26′-8″25′-2″23′-5″26′-8″24′-3″22′-11″21′-4″
1000S162-4323′-6″19′-2″16′-9″14′-2″19′-11″16′-2″14′-0″11′-9″
1000S162-5428′-2″23′-10″21′-7″18′-11″24′-8″20′-11″18′-9″18′-4″
1000S162-6831′-10″28′-11″27′-2″25′-3″28′-11″26′-3″24′-9″22′-9″
1000S162-9735′-4″32′-1″30′-3″28′-1″32′-1″29′-2″27′-6″25′-6″
1200S162-4322′-11″18′-5″16′-0″13′-4″19′-2″15′-4″13′-2″10′-6″
1200S162-5432′-8″28′-1″24′-9″21′-2″29′-0″23′-10″20′-11″17′-9″
1200S162-6837′-1″32′-5″29′-4″25′-10″33′-4″28′-6″25′-9″22′-7″
1200S162-9741′-2″37′-6″35′-3″32′-9″37′-6″34′-1″32′-1″29′-9″
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Deflection criteria: L/480 for live loads, L/240 for total loads.
b. Floor dead load = 10 psf.
c. Table provides the maximum clear span in feet and inches to either side of the interior support.
d. Interior bearing supports for multiple span joists consist of structural (bearing) walls or beams.
e. Bearing stiffeners are to be installed at all support points and concentrated loads.
f. Interior supports shall be located within 2 feet of mid-span provided that each of the resulting spans does not exceed the appropriate maximum span shown in the table above.
Joist bracing and blocking shall be in accordance with this section.
The top flanges of cold-formed steel joists shall be laterally braced by the application of floor sheathing fastened to the joists in accordance with Section R505.2.4 and Table R505.3.1(2).
Floor joists with spans that exceed 12 feet (3658 mm) shall have the bottom flanges laterally braced in accordance with one of the following:
1. Gypsum board installed with minimum No. 6 screws in accordance with Section R702.
2. Continuous steel straps installed in accordance with Figure R505.3.3.2(1). Steel straps shall be spaced at a maximum of 12 feet (3658 mm) on center and shall be at least 11/2 inches (38 mm) in width and 33 mils (0.84 mm) in thickness. Straps shall be fastened to the bottom flange of each joist with one No. 8 screw, fastened to blocking with two No. 8 screws, and fastened at each end (of strap) with two No. 8 screws. Blocking in accordance with Figure R505.3.3.2(1) or Figure R505.3.3.2(2) shall be installed between joists at each end of the continuous strapping and at a maximum spacing of 12 feet (3658 mm) measured along the continuous strapping (perpendicular to the joist run). Blocking shall also be located at the termination of all straps. As an alternative to blocking at the ends, anchoring the strap to a stable building component with two No. 8 screws shall be permitted.
For SI: 1 mil = 0.0254, 1 inch = 25.4 mm.

FIGURE R505.3.3.2(1)
JOIST BLOCKING (SOLID)

For SI: 1 mil = 0.0254, 1 inch = 25.4 mm.

FIGURE R505.3.3.2(2)
JOIST BLOCKING (STRAP)

Blocking is not required for continuous back-to-back floor joists at bearing supports. Blocking shall be installed between every other joist for single continuous floor joists across bearing supports in accordance with Figure R505.3.1(7). Blocking shall consist of C-shape or track section with a minimum thickness of 33 mils (0.84 mm). Blocking shall be fastened to each adjacent joist through a 33-mil (0.84 mm) clip angle, bent web of blocking or flanges of web stiffeners with two No. 8 screws on each side. The minimum depth of the blocking shall be equal to the depth of the joist minus 2 inches (51 mm). The minimum length of the angle shall be equal to the depth of the joist minus 2 inches (51 mm).
Blocking shall be installed between every other joist over cantilever bearing supports in accordance with Figure R505.3.1(4), R505.3.1(5) or R505.3.1(6). Blocking shall consist of C-shape or track section with minimum thickness of 33 mils (0.84 mm). Blocking shall be fastened to each adjacent joist through bent web of blocking, 33 mil clip angle or flange of web stiffener with two No. 8 screws at each end. The depth of the blocking shall be equal to the depth of the joist. The minimum length of the angle shall be equal to the depth of the joist minus 2 inches (51 mm). Blocking shall be fastened through the floor sheathing and to the support with three No. 8 screws (top and bottom).
Bearing stiffeners shall be installed at each joist bearing location in accordance with this section, except for joists lapped over an interior support not carrying a load-bearing wall above. Floor joists supporting jamb studs with multiple members shall have two bearing stiffeners in accordance with Figure R505.3.4(1). Bearing stiffeners shall be fabricated from a C-shaped, track or clip angle member in accordance with the one of following:
1. C-shaped bearing stiffeners:
1.1. Where the joist is not carrying a load-bearing wall above, the bearing stiffener shall be a minimum 33 mil (0.84 mm) thickness.
1.2. Where the joist is carrying a load-bearing wall above, the bearing stiffener shall be at least the same designation thickness as the wall stud above.
2. Track bearing stiffeners:
2.1. Where the joist is not carrying a load-bearing wall above, the bearing stiffener shall be a minimum 43 mil (1.09 mm) thickness.
2.2. Where the joist is carrying a load-bearing wall above, the bearing stiffener shall be at least one designation thickness greater than the wall stud above.
3. Clip angle bearing stiffeners: Where the clip angle bearing stiffener is fastened to both the web of the member it is stiffening and an adjacent rim track using the fastener pattern shown in Figure R505.3.4(2), the bearing stiffener shall be a minimum 2 inch by 2 inch (51 mm by 51 mm) angle sized in accordance with Tables R505.3.4(1), R505.3.4(2), R505.3.4(3), and R505.3.4(4).

The minimum length of a bearing stiffener shall be the depth of member being stiffened minus 3/8 inch (9.5 mm). Each bearing stiffener shall be fastened to the web of the member it is stiffening as shown in Figure R505.3.4(2). Each clip angle bearing stiffener shall also be fastened to the web of the adjacent rim track using the fastener pattern shown in Figure R505.3.4(2). No. 8 screws shall be used for C-shaped and track members of any thickness and for clip angle members with a designation thickness less than or equal to 54. No. 10 screws shall be used for clip angle members with a designation thickness greater than 54.

FIGURE R505.3.4(1)
BEARING STIFFENERS UNDER JAMB STUDS

For SI: 1 inch = 25.4 mm.

FIGURE R505.3.4(2)
BEARING STIFFENER

TABLE R505.3.4(1)
CLIP ANGLE BEARING STIFFENERS
(20 psf equivalent snow load)

JOIST DESIGNATIONMINIMUM THICKNESS (mils) OF 2 INCH × 2 INCH CLIP ANGLE
Top floorBottom floor in 2 story
Middle floor in 3 story
Bottom floor in 3 story
Joist spacing (inches)Joist spacing (inches)Joist spacing (inches)
121619.224121619.224121619.224
800S162-334343434343546868689797
800S162-43434343435454686897979797
800S162-544343434343546868689797
800S162-684343434343435468549797
800S162-97434343434343434343435497
1000S162-43434343435468979797
1000S162-5443434343546868979797
1000S162-68434343435468979797
1000S162-974343434343434354436897
1200S162-434354545497979797
1200S162-545454545497979797
1200S162-684343545468979797
1200S162-97434343434354689797
For SI: 1 mil = 0.254 mm, 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.

TABLE R505.3.4(2)
CLIP ANGLE BEARING STIFFENERS
(30 psf equivalent snow load)

JOIST DESIGNATIONMINIMUM THICKNESS (mils) OF 2 INCH × 2 INCH CLIP ANGLE
Top floorBottom floor in 2 story
Middle floor in 3 story
Bottom floor in 3 story
Joist spacing (inches)Joist spacing (inches)Joist spacing (inches)
121619.224121619.224121619.224
800S162-334343434354686897979797
800S162-434343435468686897979797
800S162-5443434343546868979797
800S162-684343434343546897689797
800S162-97434343434343434343436897
1000S162-43545454546897979797
1000S162-54545454546897979797
1000S162-684343546868979797
1000S162-9743434343434354685497
1200S162-4354686868979797
1200S162-54686868689797
1200S162-6868686868979797
1200S162-974343434354689797
For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.

TABLE R505.3.4(3)
CLIP ANGLE BEARING STIFFENERS
(50 psf equivalent snow load)

JOIST DESIGNATIONMINIMUM THICKNESS (mils) OF 2 INCH × 2 INCH CLIP ANGLE
Top floorBottom floor in 2 story
Middle floor in 3 story
Bottom floor in 3 story
Joist spacing (inches)Joist spacing (inches)Joist spacing (inches)
121619.224121619.224121619.224
800S162-33545454546897979797
800S162-436868686897979797
800S162-545468686897979797
800S162-68434354546897979797
800S162-974343434343434354546897
1000S162-439768686897979797
1000S162-5497976868979797
1000S162-686897979797
1000S162-974343434354689797
1200S162-4397979797
1200S162-54979797
1200S162-6897979797
1200S162-975468689797
For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.

TABLE R505.3.4(4)
CLIP ANGLE BEARING STIFFENERS
(70 psf equivalent snow load)

JOIST DESIGNATIONMINIMUM THICKNESS (mils) OF 2 INCH × 2 INCH CLIP ANGLE
Top floorBottom floor in 2 story
Middle floor in 3 story
Bottom floor in 3 story
Joist spacing (inches)Joist spacing (inches)Joist spacing (inches)
121619.224121619.224121619.224
800S162-336868686897979797
800S162-4397979797979797
800S162-549797979797
800S162-6868686897979797
800S162-9743434343435468979797
1000S162-4397979797
1000S162-54979797
1000S162-689797
1000S162-97686868689797
1200S162-4397979797
1200S162-54
1200S162-68
1200S162-97979797
For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
Flanges and lips of load-bearing cold-formed steel floor framing members shall not be cut or notched.
Floor cantilevers for the top floor of a two- or three-story building or the first floor of a one-story building shall not exceed 24 inches (610 mm). Cantilevers, not exceeding 24 inches (610 mm) and supporting two stories and roof (i.e., first floor of a two-story building), shall also be permitted provided that all cantilevered joists are doubled (nested or back-to-back). The doubled cantilevered joists shall extend a minimum of 6 feet (1829 mm) toward the inside and shall be fastened with a minimum of two No. 8 screws spaced at 24 inches (610 mm) on center through the webs (for back-to-back) or flanges (for nested joists).
Joists and other structural members shall not be spliced. Splicing of tracks shall conform to Figure R505.3.7.
For SI: 1 inch = 25.4 mm.

FIGURE R505.3.7
TRACK SPLICE

Openings in floors shall be framed with header and trimmer joists. Header joist spans shall not exceed 6 feet (1829 mm) or 8 feet (2438 mm) in length in accordance with Figure R505.3.8(1) or R505.3.8(2), respectively. Header and trimmer joists shall be fabricated from joist and track members, having a minimum size and thickness at least equivalent to the adjacent floor joists and shall be installed in accordance with Figures R505.3.8(1), R505.3.8(2), R505.3.8(3), and R505.3.8(4). Each header joist shall be connected to trimmer joists with four 2 inch by 2 inch (51 mm by 51 mm) clip angles. Each clip angle shall be fastened to both the header and trimmer joists with four No. 8 screws, evenly spaced, through each leg of the clip angle. The clip angles shall have a thickness not less than that of the floor joist. Each track section for a built-up header or trimmer joist shall extend the full length of the joist (continuous).
For SI: 1 foot = 304.8 mm.

FIGURE R505.3.8(1)
COLD-FORMED STEEL FLOOR CONSTRUCTION: 6-FOOT FLOOR OPENING

For SI: 1 foot = 304.8 mm.

FIGURE R505.3.8(2)
COLD-FORMED STEEL FLOOR CONSTRUCTION—8-FOOT FLOOR OPENING

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE R505.3.8(3)
COLD-FORMED STEEL FLOOR CONSTRUCTION: FLOOR HEADER TO TRIMMER CONNECTION—6-FOOT OPENING

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE R505.3.8(4)
COLD-FORMED STEEL FLOOR CONSTRUCTION: FLOOR HEADER TO TRIMMER CONNECTION—8-FOOT OPENING

Concrete slab-on-ground floors shall be designed and constructed in accordance with the provisions of this section or ACI 332. Floors shall be a minimum 3.5 inches (89 mm) thick (for expansive soils, see Section R403.1.8). The specified compressive strength of concrete shall be as set forth in Section R402.2.
The area within the foundation walls shall have all vegetation, top soil and foreign material removed.
Fill material shall be free of vegetation and foreign material. The fill shall be compacted to assure uniform support of the slab, and except where approved, the fill depths shall not exceed 24 inches (610 mm) for clean sand or gravel and 8 inches (203 mm) for earth.
A 4-inch-thick (102 mm) base course consisting of clean graded sand, gravel, crushed stone or crushed blast-furnace slag passing a 2-inch (51 mm) sieve shall be placed on the prepared subgrade when the slab is below grade.

Exception: A base course is not required when the concrete slab is installed on well-drained or sand-gravel mixture soils classified as Group I according to the United Soil Classification System in accordance with Table R405.1.

A 6-mil (0.006 inch; 152 µm) polyethylene or approved vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the concrete floor slab and the base course or the prepared subgrade where no base course exists.

Exception: The vapor retarder may be omitted:

1. From garages, utility buildings and other unheated accessory structures.
2. For unheated storage rooms having an area of less than 70 square feet (6.5 m2) and carports.
3. From driveways, walks, patios and other flatwork not likely to be enclosed and heated at a later date.
4. Where approved by the building official, based on local site conditions.
Where provided in slabs on ground, reinforcement shall be supported to remain in place from the center to upper one third of the slab for the duration of the concrete placement.
Relocated
Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting. For decks with cantilevered framing members, connections to exterior walls or other framing members, shall be designed and constructed to resist uplift resulting from the full live load specified in Table R301.5 acting on the cantilevered portion of the deck.
For decks supporting a total design load of 50 pounds per square foot (2394 Pa) [40 pounds per square foot (1915 Pa) live load plus 10 pounds per square foot (479 Pa) dead load], the connection between a deck ledger of pressure-preservative-treated Southern Pine, incised pressure-preservative-treated Hem-Fir or approved decay-resistant species, and a 2-inch (51 mm) nominal lumber band joist bearing on a sill plate or wall plate shall be constructed with 1/2-inch (12.7 mm) lag screws or bolts with washers in accordance with Table R507.2. Lag screws, bolts and washers shall be hot-dipped galvanized or stainless steel.

TABLE R507.2
FASTENER SPACING FOR A SOUTHERN PINE OR HEM-FIR DECK LEDGER AND
A 2-INCH-NOMINAL SOLID-SAWN SPRUCE-PINE-FIR BAND JOISTc, f, g
(Deck live load = 40 psf, deck dead load = 10 psf)

JOIST SPAN6′ and less6′1″ to 8′8′1″ to 10′10′1″ to 12′12′1″ to 14′14′1″ to 16′16′1″ to 18′
Connection detailsOn-center spacing of fastenersd, e
1/2 inch diameter lag screw with 15/32 inch
maximum sheathinga
30231815131110
1/2 inch diameter bolt with 15/32 inch maximum sheathing36363429242119
1/2 inch diameter bolt with 15/32 inch maximum sheathing and 1/2 inch stacked washersb, h36362924211816
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. 1 pound per square foot = 0.0479 kPa.
a. The tip of the lag screw shall fully extend beyond the inside face of the band joist.
b. The maximum gap between the face of the ledger board and face of the wall sheathing shall be 1/2 inch.
c. Ledgers shall be flashed to prevent water from contacting the house band joist.
d. Lag screws and bolts shall be staggered in accordance with Section R507.2.1.
e. Deck ledger shall be minimum 2 × 8 pressure-preservative-treated No. 2 grade lumber, or other approved materials as established by standard engineering practice.
f. When solid-sawn pressure-preservative-treated deck ledgers are attached to a minimum 1-inch-thick engineered wood product (structural composite lumber, laminated veneer lumber or wood structural panel band joist), the ledger attachment shall be designed in accordance with accepted engineering practice.
g. A minimum 1 × 91/2 Douglas Fir laminated veneer lumber rimboard shall be permitted in lieu of the 2-inch nominal band joist.
h. Wood structural panel sheathing, gypsum board sheathing or foam sheathing not exceeding 1 inch in thickness shall be permitted. The maximum distance between the face of the ledger board and the face of the band joist shall be 1 inch.
The lag screws or bolts in deck ledgers and band joists shall be placed in accordance with Table R507.2.1 and Figures R507.2.1(1) and R507.2.1(2).

TABLE 507.2.1
PLACEMENT OF LAG SCREWS AND BOLTS IN DECK LEDGERS AND BAND JOISTS

MINIMUM END AND EDGE DISTANCES AND SPACING BETWEEN ROWS
TOP EDGEBOTTOM EDGEENDSROW SPACING
Ledgera2 inchesd3/4 inch2 inchesb15/8 inchesb
Band Joistc3/4 inch2 inches2 inchesb15/8 inchesb
For SI: 1 inch = 25.4 mm.
a. Lag screws or bolts shall be staggered from the top to the bottom along the horizontal run of the deck ledger in accordance with Figure R507.2.1(1).
b. Maximum 5 inches.
c. For engineered rim joists, the manufacturer's recommendations shall govern.
d. The minimum distance from bottom row of lag screws or bolts to the top edge of the ledger shall be in accordance with Figure R507.2.1(1).
For SI: 1 inch = 25.4 mm.

FIGURE R507.2.1(1)
PLACEMENT OF LAG SCREWS AND BOLTS IN LEDGERS

For SI: 1 inch = 25.4 mm.

FIGURE R507.2.1(2)
PLACEMENT OF LAG SCREWS AND BOLTS IN BAND JOISTS

Deck ledger connections not conforming to Table R507.2 shall be designed in accordance with accepted engineering practice. Girders supporting deck joists shall not be supported on deck ledgers or band joists. Deck ledgers shall not be supported on stone or masonry veneer.
The lateral load connection required by Section R507.1 shall be permitted to be in accordance with Figure R507.2.3. Where the lateral load connection is provided in accordance with Figure 507.2.3, hold-down tension devices shall be installed in not less than two locations per deck, and each device shall have an allowable stress design capacity of not less than 1500 pounds (6672 N).
For SI: 1 inch = 25.4 mm.

FIGURE 507.2.3
DECK ATTACHMENT FOR LATERAL LOADS

Wood/plastic composites used in exterior deck boards, stair treads, handrails and guardrail systems shall bear a label indicating the required performance levels and demonstrating compliance with the provisions of ASTM D 7032.
Wood/plastic composites shall be installed in accordance with the manufacturer's instructions.
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