CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2012 (IRC 2012)

Copyright

Preface

Effective Use of the International Residential Code

Legislation

Part I ‒ Administrative

Chapter 1 Scope and Administration

Part II ‒ Definitions

Chapter 2 Definitions

Part III ‒ Building Planning and Construction

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

Part IV ‒ Energy Conservation

Chapter 11 [Re] Energy Efficiency

Part V ‒ Mechanical

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

Part VI ‒ Fuel Gas

Chapter 24 Fuel Gas

Part VII Plumbing Administration

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

Part VIII ‒ Electrical

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

Part IX ‒ Referenced Standards

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 roof-ceiling system for all buildings.
Roof and ceiling construction shall be capable of accommodating all loads imposed according to Section R301 and of transmitting the resulting loads to the supporting structural elements.
In areas where expansive or collapsible soils are known to exist, all dwellings shall have a controlled method of water disposal from roofs that will collect and discharge roof drainage to the ground surface at least 5 feet (1524 mm) from foundation walls or to an approved drainage system.
Load-bearing dimension lumber for rafters, trusses and ceiling joists 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.
Blocking shall be a minimum of utility grade lumber.
Approved end-jointed lumber identified by a grade mark conforming to Section R802.1 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.
Fire-retardant-treated wood (FRTW) is any wood product which, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E 84 or UL 723, a listed flame spread index of 25 or less and shows no evidence of significant progressive combustion when the test is continued for an additional 20-minute period. In addition, the flame front shall not progress more than 10.5 feet (3200 mm) beyond the center line of the burners at any time during the test.
For wood products impregnated with chemicals by a pressure process, the process shall be performed in closed vessels under pressures not less than 50 pounds per square inch gauge (psig) (344.7 kPa).
For wood products produced by other means during manufacture the treatment shall be an integral part of the manufacturing process of the wood product. The treatment shall provide permanent protection to all surfaces of the wood product.
For wood products produced by other means during manufacture, other than a pressure process, all sides of the wood product shall be tested in accordance with and produce the results required in Section R802.1.3. Testing of only the front and back faces of wood structural panels shall be permitted.
Fire-retardant-treated lumber and wood structural panels shall be labeled. The label shall contain:
1. The identification mark of an approved agency in accordance with Section 1703.5 of the International Building Code.
2. Identification of the treating manufacturer.
3. The name of the fire-retardant treatment.
4. The species of wood treated.
5. Flame spread index and smoke-developed index.
6. Method of drying after treatment.
7. Conformance to applicable standards in accordance with Sections R802.1.3.5 through R802.1.3.8.
8. For FRTW exposed to weather, or a damp or wet location, the words “No increase in the listed classification when subjected to the Standard Rain Test” (ASTM D 2898).
Design values for untreated lumber and wood structural panels as specified in Section R802.1 shall be adjusted for fire-retardant-treated wood. Adjustments to design values shall be based upon an approved method of investigation which takes into consideration the effects of the anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and redrying procedures.
The effect of treatment and the method of redrying after treatment, and exposure to high temperatures and high humidities on the flexure properties of fire-retardant-treated softwood plywood shall be determined in accordance with ASTM D 5516. The test data developed by ASTM D 5516 shall be used to develop adjustment factors, maximum loads and spans, or both for untreated plywood design values in accordance with ASTM D 6305. Each manufacturer shall publish the allowable maximum loads and spans for service as floor and roof sheathing for their treatment.
For each species of wood treated, the effect of the treatment and the method of redrying after treatment and exposure to high temperatures and high humidities on the allowable design properties of fire-retardant-treated lumber shall be determined in accordance with ASTM D 5664. The test data developed by ASTM D 5664 shall be used to develop modification factors for use at or near room temperature and at elevated temperatures and humidity in accordance with ASTM D 6841. Each manufacturer shall publish the modification factors for service at temperatures of not less than 80°F (27°C) and for roof framing. The roof framing modification factors shall take into consideration the climatological location.
Where fire-retardant-treated wood is exposed to weather or damp or wet locations, it shall be identified as “Exterior” to indicate there is no increase in the listed flame spread index as defined in Section R802.1.3 when subjected to ASTM D 2898.
Interior fire-retardant-treated wood shall have a moisture content of not over 28 percent when tested in accordance with ASTM D 3201 procedures at 92 percent relative humidity. Interior fire-retardant-treated wood shall be tested in accordance with Section R802.1.3.5.1 or R802.1.3.5.2. Interior fire-retardant-treated wood designated as Type A shall be tested in accordance with the provisions of this section.
Fire-retardant-treated wood shall be dried to a moisture content of 19 percent or less for lumber and 15 percent or less for wood structural panels before use. For wood kiln dried after treatment (KDAT) the kiln temperatures shall not exceed those used in kiln drying the lumber and plywood submitted for the tests described in Section R802.1.3.5.1 for plywood and R802.1.3.5.2 for lumber.
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.
The framing details required in Section R802 apply to roofs having a minimum slope of three units vertical in 12 units horizontal (25-percent slope) or greater. Roof-ceilings shall be designed and constructed in accordance with the provisions of this chapter and Figures R606.11(1), R606.11(2) and R606.11(3) or in accordance with AFPA/NDS. Components of roof-ceilings shall be fastened in accordance with Table R602.3(1).

R802.3 Framing Details

STATE AMENDMENT
Rafters shall be framed to ridge board or to each other with a gusset plate as a tie. Ridge board shall be at least 1-inch (25 mm) nominal thickness and not less in depth than the cut end of the rafter.Rafters shall be framed to ridge board or to each other with a gusset plate as a tie. Where rafters meet to form a ridge, they shall be placed directly opposite each other, or centerline offset not more than 11/2 inches (38 mm). Ridge board shall be at least 1-inch (25 mm) nominal thickness and not less in depth than the cut end of the rafter. At all valleys and hips there shall be a valley or hip rafter not less than 2-inch (51 mm) nominal thickness and not less in depth than the cut end of the rafter. Hip and valley rafters shall be supported at the ridge by a brace to a bearing partition or be designed to carry and distribute the specific load at that point. Where the roof pitch is less than three units vertical in 12 units horizontal (25-percent slope), structural members that support rafters and ceiling joists, such as ridge beams, hips and valleys, shall be designed as beams.

Effective January 1, 2014
Ceiling joists and rafters shall be nailed to each other in accordance with Table R802.5.1(9), and the rafter shall be nailed to the top wall plate in accordance with Table R602.3(1). Ceiling joists shall be continuous or securely joined in accordance with Table R802.5.1(9) where they meet over interior partitions and are nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters.

Where ceiling joists are not connected to the rafters at the top wall plate, joists connected higher in the attic shall be installed as rafter ties, or rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters, rafter ties shall be installed. Rafter ties shall be a minimum of 2 inches by 4 inches (51 mm by 102 mm) (nominal), installed in accordance with the connection requirements in Table R802.5.1(9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practice.

Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic space in accordance with Table R602.3(1).

Collar ties shall be a minimum of 1 inch by 4 inches (25 mm by 102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center.

Ends of ceiling joists shall be lapped a minimum of 3 inches (76 mm) or butted over bearing partitions or beams and toenailed to the bearing member. Where ceiling joists are used to provide resistance to rafter thrust, lapped joists shall be nailed together in accordance with Table R802.5.1(9) and butted joists shall be tied together in a manner to resist such thrust. Joists that do not resist thrust shall be permitted to be nailed in accordance with Table R602.3(1).
Spans for ceiling joists shall be in accordance with Tables R802.4(1) and R802.4(2). For other grades and species and for other loading conditions, refer to the AF&PA; Span Tables for Joists and Rafters.

TABLE R802.4(1)
CEILING JOIST SPANS FOR COMMON LUMBER SPECIES
(Uninhabitable attics without storage, live load = 10 psf, L/Δ = 240)

CEILING JOIST
SPACING (inches)
SPECIES AND GRADEDEAD LOAD = 5 psf
2 × 42 × 62 × 82 × 10
Maximum ceiling joist spans
(feet - inches)(feet - inches)(feet - inches)(feet - inches)
12Douglas fir-larchSS13-220-8Note aNote a
Douglas fir-larch#112-819-11Note aNote a
Douglas fir-larch#212-519-625-8Note a
Douglas fir-larch#310-1015-1020-124-6
Hem-firSS12-519-625-8Note a
Hem-fir#112-219-125-2Note a
Hem-fir#211-718-224-0Note a
Hem-fir#310-1015-1020-124-6
Southern pineSS 12-11 20-3 Note a Note a
Southern pine#1 12-5 19-6 25-8 Note a
Southern pine#2 11-10 18-8 24-7 Note a
Southern pine#3 10-1 14-11 18-9 22-9
Spruce-pine-firSS12-219-125-2Note a
Spruce-pine-fir#111-1018-824-7Note a
Spruce-pine-fir#211-1018-824-7Note a
Spruce-pine-fir#310-1015-1020-124-6
16Douglas fir-larchSS11-1118-924-8Note a
Douglas fir-larch#111-618-123-10Note a
Douglas fir-larch#211-317-823-0Note a
Douglas fir-larch#39-513-917-521-3
Hem-firSS11-317-823-4Note a
Hem-fir#111-017-422-10Note a
Hem-fir#210-616-621-9Note a
Hem-fir#39-513-917-521-3
Southern pineSS 11-9 18-5 24-3 Note a
Southern pine#1 11-3 17-8 23-4 Note a
Southern pine#2 10-9 16-11 21-7 25-7
Southern pine#3 8-9 12-11 16-3 19-9
Spruce-pine-firSS11-017-422-10Note a
Spruce-pine-fir#110-916-1122-4Note a
Spruce-pine-fir#210-916-1122-4Note a
Spruce-pine-fir#39-513-917-521-3

(continued)

TABLE R802.4(1)—continued
CEILING JOIST SPANS FOR COMMON LUMBER SPECIES
(Uninhabitable attics without storage, live load = 10 psf, L/Δ = 240)

CEILING JOIST
SPACING (inches)
SPECIES AND GRADEDEAD LOAD = 5 psf
2 × 42 × 62 × 82 × 10
Maximum ceiling joist spans
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Douglas fir-larchSS11-317-823-3Note a
Douglas fir-larch#110-1017-022-5Note a
Douglas fir-larch#210-716-721-025-8
Douglas fir-larch#38-712-615-1019-5
Hem-firSS10-716-821-11Note a
Hem-fir#110-416-421-6Note a
Hem-fir#29-1115-720-625-3
Hem-fir#38-712-615-1019-5
Southern -pineSS11-017-422-10Note a
Southern pine#1 11-0 17-4 22-10 Note a
Southern pine#2 10-2 15-7 19-8 23-5
Southern pine#3 8-0 11-9 14-10 18-0
Spruce-pine-firSS10-416-421-6Note a
Spruce-pine-fir#110-215-1121-025-8
Spruce-pine-fir#210-215-1121-025-8
Spruce-pine-fir#38-712-615-1019-5
24Douglas fir-larchSS10-516-421-7Note a
Douglas fir-larch#110-015-920-124-6
Douglas fir-larch#29-1014-1018-922-11
Douglas fir-larch#37-811-214-217-4
Hem-firSS9-1015-620-5Note a
Hem-fir#19-815-219-723-11
Hem-fir#29-214-518-622-7
Hem-fir#37-811-214-217-4
Southern pineSS 10-3 16-1 21-2 Note a
Southern pine#1 9-10 15-6 20-5 24-0
Southern pine#2 9-3 13-11 17-7 20-11
Southern pine#3 7-2 10-6 13-3 16-1
Spruce-pine-firSS9-815-219-1125-5
Spruce-pine-fir#19-514-918-922-11
Spruce-pine-fir#29-514-918-922-11
Spruce-pine-fir#37-811-214-217-4
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479kPa.
a. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.4(2)
CEILING JOIST SPANS FOR COMMON LUMBER SPECIES
(Uninhabitable attics with limited storage, live load = 20 psf, L/Δ = 240)

CEILING JOIST
SPACING (inches)
SPECIES AND GRADEDEAD LOAD = 10 psf
2 × 42 × 62 × 82 × 10
Maximum ceiling joist spans
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larchSS10-516-421-7Note a
Douglas fir-larch #110-015-920-124-6
Douglas fir-larch #29-1014-1018-922-11
Douglas fir-larch #37-811-214-217-4
Hem-fir SS9-1015-620-5Note a
Hem-fir #19-815-219-723-11
Hem-fir #29-214-518-622-7
Hem-fir #37-811-214-217-4
Southern pine SS 10-3 16-1 21-2 Note a
Southern pine #1 9-10 15-6 20-5 24-0
Southern pine #2 9-3 13-11 17-7 20-11
Southern pine #3 7-2 10-6 13-3 16-1
Spruce-pine-fir SS9-815-219-1125-5
Spruce-pine-fir #19-514-918-922-11
Spruce-pine-fir #29-514-918-922-11
Spruce-pine-fir #37-811-214-217-4
16Douglas fir-larch SS9-614-1119-725-0
Douglas fir-larch #19-113-917-521-3
Douglas fir-larch #28-912-1016-319-10
Douglas fir-larch #36-89-812-415-0
Hem-fir SS8-1114-118-623-8
Hem-fir #18-913-516-1020-8
Hem-fir #28-412-816-019-7
Hem-fir #36-89-812-415-0
Southern pine SS 9-4 14-7 19-3 24-7
Southern pine #1 8-11 14-0 17-9 20-9
Southern pine #2 8-0 12-0 15-3 18-1
Southern pine #3 6-2 9-2 11-6 14-0
Spruce-pine-fir SS8-913-918-123-1
Spruce-pine-fir #18-712-1016-319-10
Spruce-pine-fir #28-712-1016-319-10
Spruce-pine-fir #36-89-812-415-0

(continued)

TABLE R802.4(2)—continued
CEILING JOIST SPANS FOR COMMON LUMBER SPECIES
(Uninhabitable attics with limited storage, live load = 20 psf, L/Δ = 240)

CEILING JOIST
SPACING (inches)
SPECIES AND GRADEDEAD LOAD = 10 psf
2 × 42 × 62 × 82 × 10
Maximum ceiling joist spans
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Douglas fir-larch SS8-1114-018-523-4
Douglas fir-larch #18-712-615-1019-5
Douglas fir-larch #28-011-914-1018-2
Douglas fir-larch #36-18-1011-313-8
Hem-fir SS8-513-317-522-3
Hem-fir #18-312-315-618-11
Hem-fir #27-1011-714-817-10
Hem-fir #36-18-1011-313-8
Southern pine SS 8-9 13-9 18-2 23-1
Southern pine #1 8-5 12-9 16-2 18-11
Southern pine #2 7-4 11-0 13-11 16-6
Southern pine #3 5-8 8-4 10-6 12-9
Spruce-pine-fir SS8-312-1117-121-8
Spruce-pine-fir #18-011-914-1018-2
Spruce-pine-fir #28-011-914-1018-2
Spruce-pine-fir #36-18-1011-313-8
24Douglas fir-larch SS8-313-017-120-11
Douglas fir-larch #17-811-214-217-4
Douglas fir-larch #27-210-613-316-3
Douglas fir-larch #35-57-1110-012-3
Hem-fir SS7-1012-316-220-6
Hem-fir #17-610-1113-1016-11
Hem-fir #27-110-413-116-0
Hem-fir #35-57-1110-012-3
Southern pine SS 8-1 12-9 16-10 21-6
Southern pine #1 7-8 11-5 14-6 16-11
Southern pine #2 6-7 9-10 12-6 14-9
Southern pine #3 5-1 7-5 9-5 11-5
Spruce-pine-fir SS7-812-015-1019-5
Spruce-pine-fir #17-210-613-316-3
Spruce-pine-fir #27-210-613-316-3
Spruce-pine-fir #35-57-1110-012-3
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479kPa.
a. Span exceeds 26 feet in length.
(Effective January 1, 2015)
Spans for rafters shall be in accordance with Tables R802.5.1(1) through R802.5.1(8). For other grades and species and for other loading conditions, refer to the AF&PA; Span Tables for Joists and Rafters. The span of each rafter shall be measured along the horizontal projection of the rafter.

R802.5.1 Purlins

STATE AMENDMENT
Installation of purlins to reduce the span of rafters is permitted as shown in Figure R802.5.1. Purlins shall be sized no less than the required size of the rafters that they support. Purlins shall be continuous and shall be supported by 2-inch by 4-inch (51 mm by 102 mm) braces installed to bearing walls at a slope not less than 45 degrees (0.785 rad) from the horizontal. The braces shall be spaced not more than 4 feet (1219 mm) on center and the unbraced length of braces shall not exceed 8 feet (2438 mm).

TABLE R802.5.1(1)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Roof live load=20 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS11-618-023-9Note bNote b11-618-023-5Note bNote b
Douglas fir-larch #111-117-422-5Note bNote b10-615-419-523-9Note b
Douglas fir-larch #210-1016-721-025-8Note b9-1014-418-222-325-9
Douglas fir-larch #38-712-615-1019-522-67-510-1013-916-919-6
Hem-fir SS10-1017-022-5Note bNote b10-1017-022-5Note bNote b
Hem-fir #110 -716-821-10Note bNote b10-314-1118-1123-2Note b
Hem-fir #210-115-1120-825-3Note b9-814-217-1121-1125-5
Hem-fir #38-712-615-1019-522-67-510-1013-916-919-6
Southern pine SS 11-3 17-8 23-4 Note b Note b 11-3 17-8 23-4 Note b Note b
Southern pine #1 10-10 17-0 22-5 Note b Note b 10-6 15-8 19-10 23-2 Note b
Southern pine #2 10-4 15-7 19-8 23-5 Note b 9-0 13-6 17-1 20-3 23-10
Southern pine #3 8-0 11-9 14-10 18-0 24-4 6-11 10-2 12-10 15-7 18-6
Spruce-pine-fir SS 10-7 16-8 21-11 Note b Note b 10-7 16-8 21-9 Note b Note b
Spruce-pine-fir #110-416-321-025-8Note b9-1014-418-222-325-9
Spruce-pine-fir #210-416-321-025-8Note b9-1014-418-222-325-9
Spruce-pine-fir #38-712-615-1019-522-67-510-1013-916-919-6
16Douglas fir-larch SS10-516-421-7Note bNote b10-516-020-324-9Note b
Douglas fir-larch #110-015-419-523-9Note b9-113-316-1020-723-10
Douglas fir-larch #29-1014-418-222-325-98-612-515-919-322-4
Douglas fir-larch #37-510-1013-916-919-66-59-511-1114-616-10
Hem-fir SS9-1015-620-5Note bNote b9-1015-619-1124-4Note b
Hem-fir #19-814-1118-1123-2Note b8-1012-1116-520-023-3
Hem-fir #29-214-217-1121-1125-58-512-315-618-1122-0
Hem-fir #37-510-1013-916-919-66-59-511-1114-616-10
Southern pine SS 10-3 16-1 21-2 Note b Note b 10-3 16-1 21-2 25-7 Note b
Southern pine #1 9-10 15-6 19-10 23-2 Note b 9-1 13-7 17-2 20-1 23-10
Southern pine #2 9-0 13-6 17-1 20-3 23-10 7-9 11-8 14-9 17-6 20-8
Southern pine #3 6-11 10-2 12-10 15-7 18-6 6-0 8-10 11-2 13-6 16-0
Spruce-pine-fir SS9-815-219-1125-5Note b9-814-1018-1023-0Note b
Spruce-pine-fir #19-514-418-222-325-98-612-515-919-322-4
Spruce-pine-fir #29-514-418-222-325-98-612-515-919-322-4
Spruce-pine-fir #37-510-1013-916-919-66-59-511-1114-616-10
19.2Douglas fir-larch SS9-1015-520-425-11Note b9-1014-718-622-7Note b
Douglas fir-larch #19-514-017-921-825-28-412-215-418-921-9
Douglas fir-larch #28-1113-116-720-323-67-911-414-417-720-4
Douglas fir-larch #36-99-1112-715-417-95-108-710-1013-315-5
Hem-fir SS9-314-719-224-6Note b9-314-418-222-325-9
Hem-fir #19-113-817-421-124-68-111-1015-018-421-3
Hem-fir #28-812-1116-420-023-27-811-214-217-420-1
Hem-fir #36-99-1112-715-417-95-108-710-1013-315-5
Southern pine SS 9-8 15-2 19-11 25-5 Note b 9-8 15-2 19-7 23-4 Note b
Southern pine #1 9-3 14-3 18-1 21-2 25-2 8-4 12-4 15-8 18-4 21-9
Southern pine #2 8-2 12-3 15-7 18-6 21-9 7-1 10-8 13-6 16-0 18-10
Southern pine #3 6-4 9-4 11-9 14-3 16-10 5-6 8-1 10-2 12-4 14-7
Spruce-pine-fir SS9-114-318-923-11Note b9-113-717-221-024-4
Spruce-pine-fir #18-1013-116-720-323-67-911-414-417-720-4
Spruce-pine-fir #28-1013-116-720-323-67-911-414-417-720-4
Spruce-pine-fir #36-99-1112-715-417-95-108-710-1013-315-5

(continued)

TABLE R802.5.1(1)—continued
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Roof live load=20 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
24Douglas fir-larch SS9-114-418-1023-4Note b8-1113-116-720-323-5
Douglas fir-larch #18-712-615-1019-522-67-510-1013-916-919-6
Douglas fir-larch #28-011-914-1018-221-06-1110-212-1015-818-3
Douglas fir-larch #36-18-1011-313-815-115-37-89-911-1013-9
Hem-fir SS8-713-617-1022-9Note b8-712-1016-319-1023-0
Hem-fir #18-412-315-618-1121-117-310-713-516-419-0
Hem-fir #27-1111-714-817-1020-96-1010-012-815-617-11
Hem-fir #36-18-1011-313-815-115-37-89-911-1013-9
Southern pine SS 8-11 14-1 18-6 23-8 Note b 8-11 13-10 17-6 20-10 24-8
Southern pine #1 8-7 12-9 16-2 18-11 22-6 7-5 11-1 14-0 16-5 19-6
Southern pine #2 7-4 11-0 13-11 16-6 19.6 6-4 9-6 12-1 14-4 16-10
Southern pine #3 5-8 8-4 10-6 12-9 15-1 4-11 7-3 9-1 11-0 13-1
Spruce-pine-fir SS8-513-317-521-825-28-412-215-418-921-9
Spruce-pine-fir #18-011-914-1018-221-06-1110-212-1015-818-3
Spruce-pine-fir #28-011-914-1018-221-06-1110-212-1015-818-3
Spruce-pine-fir #36-18-1011-313-815-115-37-89-911-1013-9
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
b. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.5.1(2)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Roof live load=20 psf, ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS10-516-421-7Note bNote b10-516-421-7Note bNote b
Douglas fir-larch #110-015-920-10Note bNote b10-015-419-523-9Note b
Douglas fir-larch #29-1015-620-525-8Note b9-1014-418-222-325-9
Douglas fir-larch #38-712-615-1019-522-67-510-1013-916-919-6
Hem-fir SS9-1015-620-5Note bNote b9-1015-620-5Note bNote b
Hem-fir #19-815-219-1125-5Note b9-814-1118-1123-2Note b
Hem-fir #29-214-519-024-3Note b9-214-217-1121-1125-5
Hem-fir #38-712-615-1019-522-67-510-1013-916-919-6
Southern pine SS 10-3 16-1 21-2 Note b Note b 10-3 16-1 21-2 Note b Note b
Southern pine #1 9-10 15-6 20-5 Note b Note b 9-10 15-6 19-10 23-2 Note b
Southern pine #2 9-5 14-9 19-6 23-5 Note b 9-0 13-6 17-1 20-3 23-10
Southern pine #3 8-0 11-9 14-10 18-10 21-4 6-11 10-2 12-10 15-7 18-6
Spruce-pine-fir SS9-815-219-1125-5Note b9-815-219-1125-5Note b
Spruce-pine-fir #19-514-919-624-10Note b9-514-418-222-325-9
Spruce-pine-fir #29-514-919-624-10Note b9-514-418-222-325-9
Spruce-pine-fir #38-712-615-1019-522-67-510-1013-916-919-6
16Douglas fir-larch SS9-614-1119-725-0Note b9-614-1119-724-9Note b
Douglas fir-larch #19-114-418-1123-9Note b9-113-316-1020-723-10
Douglas fir-larch #28-1114-118-222-325-98-612-515-919-322-4
Douglas fir-larch #37-510-1013-916-919-66-59-511-1114-616-10
Hem-fir SS8-1114-118-623-8Note b8-1114-118-623-8Note b
Hem-fir #18-913-918-123-1Note b8-912-1116-520-023-3
Hem-fir #28-413-117-321-1125-58-412-315-618-1122-0
Hem-fir #37-510-1013-916-919-66-59-511-1114-616-10
Southern pine SS 9-4 14-7 19-3 24-7 Note b 9-4 14-7 19-3 24-7 Note b
Southern pine #1 8-11 14-1 18-6 23-2 Note b 8-11 13-7 17-2 20-1 23-10
Southern pine #2 8-7 13-5 17-1 20-3 23-10 7-9 11-8 14-9 17-6 20-8
Southern pine #3 6-11 10-2 12-10 15-7 18-6 6-0 8-10 11-2 13-6 16-0
Spruce-pine-fir SS8-913-918-123-1Note b8-913-918-123-0Note b
Spruce-pine-fir #18-713-517-922-325-98-612-515-919-322-4
Spruce-pine-fir #28-713-517-922-325-98-612-515-919-322-4
Spruce-pine-fir #37-510-1013-916-919-66-59-511-1114-616-10
19.2Douglas fir-larch SS8-1114-018-523-7Note b8-1114-018-522-7Note b
Douglas fir-larch #18-713-617-921-825-28-412-215-418-921-9
Douglas fir-larch #28-513-116-720-323-67-911-414-417-720-4
Douglas fir-larch #36-99-1112-715-417-95-108-710-1013-315-5
Hem-fir SS8-513-317-522-3Note b8-513-317-522-325-9
Hem-fir #18-312-1117-121-124-68-111-1015-018-421-3
Hem-fir #27-1012-416-320-023-27-811-214-217-420-1
Hem-fir #36-99-1112-715-417-95-108-710-1013-315-5

(continued)

TABLE R802.5.1(2)—continued
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Roof live load=20 psf, ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Southern pine SS 8-9 13-9 18-2 23-1 Note b 8-9 13-9 18-2 23-1 Note b
Southern pine #1 8-5 13-3 17-5 21-2 25-2 8-4 12-4 15-8 18-4 21-9
Southern pine #2 8-1 12-3 15-7 18-6 21-9 7-1 10-8 13-6 16-0 18-10
Southern pine #3 6-4 9-4 11-9 4-3 16-10 5-6 8-1 10-2 12-4 14-7
Spruce-pine-fir SS8-312-1117-121-9Note b8-312-1117-121-024-4
Spruce-pine-fir #18-112-816-720-323-67-911-414-417-720-4
Spruce-pine-fir #28-112-816-720-323-67-911-414-417-720-4
Spruce-pine-fir #36-99-1112-715-417-95-108-710-1013-315-5
24Douglas fir-larch SS8-313-017-22 1-10Note b8-313-016-720-323-5
Douglas fir-larch #18-012-615-1019-522-67-510-1013-916-919-6
Douglas fir-larch #27-1011-914-1018-221-06-1110-212-1015-818-3
Douglas fir-larch #36-18-1011-313-815-115-37-89-911-1013-9
Hem-fir SS7-1012-316-220-825-17-1012-316-219-1023-0
Hem-fir #17-812-015-618-1121-117-310-713-516-419-0
Hem-fir #27-311-514-817-1020-96-1010-012-815-617-11
Hem-fir #36-18-1011-313-815-115-37-89-911-1013-9
Southern pine SS 8-1 12-9 16-10 21-6 Note b 8-1 12-9 16-10 20-10 24-8
Southern pine #1 7-10 12-3 16-2 18-11 22-6 7-5 11-1 14-0 16-5 19-6
Southern pine #2 7-4 11-0 13-11 16-6 19-6 6-4 9-6 12-1 14-4 16-10
Southern pine #3 5-8 8-4 10-6 12-9 15-1 4-11 7-3 9-1 11-0 13-1
Spruce-pine-fir SS7-812-015-1020-224-77-812-015-418-921-9
Spruce-pine-fir #17-611-914-1018-221-06-1110-212-1015-818-3
Spruce-pine-fir #27-611-914-1018-221-06-1110-212-1015-818-3
Spruce-pine-fir #36-18-1011-313-815-115-37-89-911-1013-9
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
b. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.5.1(3)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=30 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS10-015-920-9Note bNote b10-015-920-124-6Note b
Douglas fir-larch #19-814-918-822-9Note b9-013-216-820-423-7
Douglas fir-larch #29-513-917-521-424-88-512-415-719-122-1
Douglas fir-larch #37-110-513-216-118-86-49-411-914-516-8
Hem-fir SS9-614-1019-725-0Note b9-614-1019-724-1Note b
Hem-fir #19-314-418-222-225-98-912-1016-319-1023-0
Hem-fir #28-1013-717-221-024-48-412-215-418-921-9
Hem-fir #37-110-513-216-118-86-49-411-914-516-8
Southern pine SS 9-10 15-6 20-5 Note b Note b 9-10 15-6 20-5 25-4 Note b
Southern pine #1 9-6 14-10 19-0 22-3 Note b 9-0 13-5 17-0 19-11 23-7
Southern pine #2 8-7 12-11 16-4 19-5 22-10 7-8 11-7 14-8 17-4 20-5
Southern pine #3 6-7 9-9 12-4 15-0 17-9 5-11 8-9 11-0 13-5 15-10
Spruce-pine-fir SS9-314-719-224-6Note b9-314-718-822-9Note b
Spruce-pine-fir #19-113-917-521-424-88-512-415-719-122-1
Spruce-pine-fir #29-113-917-521-424-88-512-415-719-122-1
Spruce-pine-fir #37-110-513-216-118-86-49-411-914-516-8
16Douglas fir-larch SS9-114-418-1023-9Note b9-113-917-521-324-8
Douglas fir-larch #18-912-916-219-922-107-1011-514-517-820-5
Douglas fir-larch #28-211-1115-118-521-57-310-813-616-619-2
Douglas fir-larch #36-29-011-513-1116-25-68-110-312-614-6
Hem-fir SS8-713-617-1022-9Note b8-713-617-120-1024-2
Hem-fir #18-512-515-919-322-37-711-114-117-219-11
Hem-fir #28-011-914-1118-221-17-210-613-416-318-10
Hem-fir #36-29-011-513-1116-25-68-110-312-614-6
Southern pine SS 8-11 14-1 18-6 23-8 Note b 8-11 14-1 18-5 22-11 25-11
Southern pine #1 8-7 13-0 16-6 19-3 22-10 7-10 11-7 14-9 17-3 20-5
Southern pine #2 7-6 11-2 14-2 16-10 19-10 6-8 10-0 12-8 15-1 17-9
Southern pine #3 5-9 8-6 10-8 13-0 15-4 5-2 7-7 9-7 11-7 13-9
Spruce-pine-fir SS8-513-317-522-125-78-512-916-219-922-10
Spruce-pine-fir #18-211-1115-118-521-57-310-813-616-619-2
Spruce-pine-fir #28-211-1115-118-521-57-310-813-616-619-2
Spruce-pine-fir #36-29-011-513-1116-25-68-110-312-614-6
19.2Douglas fir-larch SS8-713-617-921-825-28-712-615-1019-522-6
Douglas fir-larch #17-1111-814-918-020-117-110-513-216-118-8
Douglas fir-larch #27-510-1113-916-1019-66-89-912-415-117-6
Douglas fir-larch #35-78-310-512-914-95-07-49-411-513-2
Hem-fir SS8-112-916-921-424-88-112-415-719-122-1
Hem-fir #17-911-414-417-720-46-1110-212-1015-818-2
Hem-fir #27-410-913-716-719-36-79-712-214-1017-3
Hem-fir #35-78-310-512-914-95-07-49-411-513-2

(continued)

TABLE R802.5.1(3)—continued
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=30 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Southern pine SS 8-5 13-3 17-5 22-3 Note b 8-5 13-3 16-10 20-0 23-7
Southern pine #1 8-0 11-10 15-1 17-7 20-11 7-1 10-7 13-5 15-9 18-8
Southern pine #2 6-10 10-2 12-11 15-4 18-1 6-1 9-2 11-7 13-9 16-2
Southern pine #3 5-3 7-9 9-9 11-10 14-0 4-8 6-11 8-9 10-7 12-6
Spruce-pine-fir SS7-1112-516-520-223-47-1111-814-918-020-11
Spruce-pine-fir #17-510-1113-916-1019-66-89-912-415-117-6
Spruce-pine-fir #27-510-1113-916-1019-66-89-912-415-117-6
Spruce-pine-fir #35-78-310-512-914-95-07-49-411-513-2
24Douglas fir-larch SS7-1112-615-1019-522-67-811-314-217-420-1
Douglas fir-larch #17-110-513-216-118-86-49-411-914-516-8
Douglas fir-larch #26-89-912-415-117-65-118-811-013-615-7
Douglas fir-larch #35-07-49-411-513-24-66-78-410-211-10
Hem-fir SS7-611-1015-719-122-17-611-013-1117-019-9
Hem-fir #16-1110-212-1015-818-26-29-111-614-016-3
Hem-fir #26-79-712-214-1017-35-108-710-1013-315-5
Hem-fir #35-07-49-411-513-24-66-78-410-211-10
Southern pine SS 7-10 12-3 16-2 20-0 23-7 7-10 11-10 15-0 17-11 21-2
Southern pine #1 7-1 10-7 13-5 15-9 18-8 6-4 9-6 12-0 14-1 16-8
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-5 8-2 10-4 12-3 14-6
Southern pine #3 4-8 6-11 8-9 10-7 12-6 4-2 6-2 7-10 9-6 11-2
Spruce-pine-fir SS7-411-714-918-020-117-110-513-216-118-8
Spruce-pine-fir #16-89-912-415-117-65-118-811-013-615-7
Spruce-pine-fir #26-89-912-415-117-65-118-811-013-615-7
Spruce-pine-fir #35-07-49-411-513-24-66-78-410-211-10
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
b. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.5.1(4)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=50 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS8-513-317-622-426-08-513-317-020-924-0
Douglas fir-larch #18-212-015-318-721-77-711-214-117-320-0
Douglas fir-larch #27-811-314-317-520-27-110-513-216-118-8
Douglas fir-larch #35-108-610-913-215-35-57-1010-012-214-1
Hem-fir SS8-012-616-621-125-68-012-616-620-423-7
Hem-fir #17-1011-914-1018-121-07-510-1013-916-919-5
Hem-fir #27-511-114-017-219-117-010-313-015-1018-5
Hem-fir #35-108-610-913-215-35-57-1010-012-214-1
Southern pine SS 8-4 13-1 17-2 21-11 Note b 8-4 13-1 17-2 21-5 25-3
Southern pine #1 8-0 12-3 15-6 18-2 21-7 7-7 11-4 14-5 16-10 20-0
Southern pine #2 7-0 10-6 13-4 15-10 18-8 6-6 9-9 12-4 14-8 17-3
Southern pine #3 5-5 8-0 10-1 12-3 14-6 5-0 7-5 9-4 11-4 13-5
Spruce-pine-fir SS7-1012-316-220-824-17-1012-315-919-322-4
Spruce-pine-fir #17-811-314-317-520-27-110-513-216-118-8
Spruce-pine-fir #27-811-314-317-520-27-110-513-216-118-8
Spruce-pine-fir #35-108-610-913-215-35-57-1010-012-214-1
16Douglas fir-larch SS7-812-115-1019-522-67-811-714-817-1120-10
Douglas fir-larch #17-110-513-216-118-86-79-812-214-1117-3
Douglas fir-larch #26-89-912-415-117-66-29-011-513-1116-2
Douglas fir-larch #35-07-49-411-513-24-86-108-810-612-3
Hem-fir SS7-311-515-019-122-17-311-514-517-820-5
Hem-fir #16-1110-212-1015-818-26-59-511-1114-616-10
Hem-fir #26-79-712-214-1017-36-18-1111-313-915-11
Hem-fir #35-07-49-411-513-24-86-108-810-612-3
Southern pine SS 7-6 11-10 15-7 19-11 23-7 7-6 11-10 15-7 18-6 21-10
Southern pine #1 7-1 10-7 13-5 15-9 18-8 6-7 9-10 12-5 14-7 17-3
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-8 8-5 10-9 12-9 15-0
Southern pine #3 4-8 6-11 8-9 10-7 12-6 4-4 6-5 8-1 9-10 11-7
Spruce-pine-fir SS7-111-214-818-020-117-110-913-815-1119-4
Spruce-pine-fir #16-89-912-415-117-66-29-011-513-1116-2
Spruce-pine-fir #26-89-912-415-117-66-29-011-513-1116-2
Spruce-pine-fir #35-07-49-411-513-24-86-108-810-612-3
19.2Douglas fir-larch SS7-311-414-617-820-67-310-713-516-519-0
Douglas fir-larch #16-69-612-014-817-16-08-1011-213-715-9
Douglas fir-larch #26-18-1111-313-915-115-78-310-512-914-9
Douglas fir-larch #34-76-98-610-512-14-36-37-119-711-2
Hem-fir SS6-1010-914-217-520-26-1010-513-216-118-8
Hem-fir #16-49-311-914-416-75-108-710-1013-315-5
Hem-fir #26-08-911-113-715-95-78-110-312-714-7
Hem-fir #34-76-98-610-512-14-36-37-119-711-2

(continued)

TABLE R802.5.1(4)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=50 psf, ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Southern pine SS 7-1 11-2 14-8 18-3 21-7 7-1 11-2 14-2 16-11 20-0
Southern pine #1 6-6 9-8 12-3 14-4 17-1 6-0 9-0 11-4 13-4 15-9
Southern pine #2 5-7 8-4 10-7 12-6 14-9 5-2 7-9 9-9 11-7 13-8
Southern pine #3 4-3 6-4 8-0 9-8 11-5 4-0 5-10 7-4 8-11 10-7
Spruce-pine-fir SS6-810-613-516-519-16-89-1012-515-317-8
Spruce-pine-fir #16-18-1111-313-915-115-78-310-512-914-9
Spruce-pine-fir #26-18-1111-313-915-115-78-310-512-914-9
Spruce-pine-fir #34-76-98-610-512-14-36-37-119-711-2
24Douglas fir-larch SS6-810-13-015-1018-46-69-612-014-817-0
Douglas fir-larch #15-108-610-913-215-35-57-1010-012-214-1
Douglas fir-larch #25-57-1110-112-414-35-07-49-411-513-2
Douglas fir-larch #34-16-07-79-410-93-105-77-18-710-0
Hem-fir SS6-49-1112-915-718-06-49-411-914-516-8
Hem-fir #15-88-310-612-1014-105-37-89-911-1013-9
Hem-fir #25-47-109-1112-114-14-117-39-211-313-0
Hem-fir #34-16-07-79-410-93-105-77-18-710-0
Southern pine SS 6-7 10-4 13-8 16-4 19-3 6-7 10-0 12-8 15-2 17-10
Southern pine #1 5-10 8-8 11-0 12-10 15-3 5-5 8-0 10-2 11-11 14-1
Southern pine #2 5-0 7-5 9-5 11-3 13-2 4-7 6-11 8-9 10-5 12-3
Southern pine #3 3-10 5-8 7-1 8-8 10-3 3-6 5-3 6-7 8-0 9-6
Spruce-pine-fir SS6-29-612-014-817-16-08-1011-213-715-9
Spruce-pine-fir #15-57-1110-112-414-35-07-49-411-513-2
Spruce-pine-fir #25-57-1110-112-414-35-07-49-411-513-2
Spruce-pine-fir #34-16-07-79-410-93-105-77-18-710-0
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
b. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.5.1(5)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=30 psf, ceiling attached to rafters, L/
Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS9-114-418-1024-1Note b9-114-418-1024-1Note b
Douglas fir-larch #18-913-918-222-9Note b8-913-216-820-423-7
Douglas fir-larch #28-713-617-521-424-88-512-415-719-122-1
Douglas fir-larch #37-110-513-216-118-86-49-411-914-516-8
Hem-fir SS8-713-617-1022-9Note b8-713-617-1022-9Note b
Hem-fir #18-513-317-522-225-98-512-1016-319-1023-0
Hem-fir #28-012-716-721-024-48-012-215-418-921-9
Hem-fir #37-110-513-216-118-86-49-411-914-516-8
Southern pine SS 8-11 14-1 18-6 23-8 Note b 8-11 14-1 18-6 23-8 Note b
Southern pine #1 8-7 13-6 17-10 22-3 Note b 8-7 13-5 17-0 19-11 23-7
Southern pine #2 8-3 12-11 16-4 19-5 22-10 7-8 11-7 14-8 17-4 20-5
Southern pine #3 6-7 9-9 12-4 15-0 17-9 5-11 8-9 11-0 13-5 15-10
Spruce-pine-fir SS8-513-317-522-3Note b8-513-317-522-3Note b
Spruce-pine-fir #18-312-1117-021-424-88-312-415-719-122-1
Spruce-pine-fir #28-312-1117-021-424-88-312-415-719-122-1
Spruce-pine-fir #37-110-513-216-118-86-49-411-914-516-8
16Douglas fir-larch SS8-313-017-221-10Note b8-313-017-221-324-8
Douglas fir-larch #18-012-616-219-922-107-1011-514-517-820-5
Douglas fir-larch #27-1011-1115-118-521-57-310-813-616-619-2
Douglas fir-larch #36-29-011-513-1116-25-68-110-312-614-6
Hem-fir SS7-1012-316-220-825-17-1012-316-220-824-2
Hem-fir #17-812-015-919-322-37-711-114-117-219-11
Hem-fir #27-311-514-1118-221-17-210-613-416-318-10
Hem-fir #36-29-011-513-1116-25-68-110-312-614-6
Southern pine SS 8-1 12-9 16-10 21-6 Note b 8-1 12-9 16-10 21-6 25-11
Southern pine #1 7-10 12-3 16-2 19-3 22-10 7-10 11-7 14-9 17-3 20-5
Southern pine #2 7-6 11-2 14-2 16-10 19-10 6-8 10-0 12-8 15-1 17-9
Southern pine #3 5-9 8-6 10-8 13-0 15-4 5-2 7-7 9-7 11-7 13-9
Spruce-pine-fir SS7-812-015-1020-224-77-812-015-1019-922-10
Spruce-pine-fir #17-611-915-118-521-57-310-813-616-619-2
Spruce-pine-fir #27-611-915-118-521-57-310-813-616-619-2
Spruce-pine-fir #36-29-011-513-1116-25-68-110-312-614-6
19.2Douglas fir-larch SS7-912-316-120-725-07-912-315-1019-522-6
Douglas fir-larch #17-611-814-918-020-117-110-513-216-118-8
Douglas fir-larch #27-410-1113-916-1019-66-89-912-415-117-6
Douglas fir-larch #35-78-310-512-914-95-07-49-411-513-2
Hem-fir SS7-411-715-319-523-77-411-715-319-122-1
Hem-fir #17-211-414-417-720-46-1110-212-1015-818-2
Hem-fir #26-1010-913-716-719-36-79-712-214-1017-3
Hem-fir #35-78-310-512-914-95-07-49-411-513-2

(continued)

TABLE R802.5.1(5)—continued
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=30 psf, ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Southern pine SS 7-8 12-0 15-10 20-2 24-7 7-8 12-0 15-10 20-2 23-7
Southern pine #1 7-4 11-7 15-1 17-7 20-11 7-1 10-7 13-5 15-9 18-8
Southern pine #2 6-10 10-2 12-11 15-4 18-1 6-1 9-2 11-7 13-9 16-2
Southern pine #3 5-3 7-9 9-9 11-10 14-0 4-8 6-11 8-9 10-7 12-6
Spruce-pine-fir SS7-211-414-1119-023-17-211-414-918-020-11
Spruce-pine-fir #17-010-1113-916-1019-66-89-912-415-117-6
Spruce-pine-fir #27-010-1113-916-1019-66-89-912-415-117-6
Spruce-pine-fir #35-78-310-512-914-95-07-49-411-513-2
24Douglas fir-larch SS7-311-415-019-122-67-311-314-217-420-1
Douglas fir-larch #17-010-513-216-118-86-49-411-914-516-8
Douglas fir-larch #26-89-912-415-117-65-118-811-013-615-7
Douglas fir-larch #35-07-49-411-513-24-66-78-410-211-10
Hem-fir SS6-1010-914-218-021-116-1010-913-1117-019-9
Hem-fir #16-810-212-1015-818-26-29-111-614-016-3
Hem-fir #26-49-712-214-1017-35-108-710-1013-315-5
Hem-fir #35-07-49-411-513-24-66-78-410-211-10
Southern pine SS 7-1 11-2 14-8 18-9 22-10 7-1 11-2 14-8 17-11 21-2
Southern pine #1 6-10 10-7 13-5 15-9 18-8 6-4 9-6 12-0 14-1 16-8
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-5 8-2 10-4 12-3 14-6
Southern pine #3 4-8 6-11 8-9 10-07 12-6 4-2 6-2 7-10 9-6 11-2
Spruce-pine-fir SS6-810-613-1017-820-116-810-513-216-118-8
Spruce-pine-fir #16-69-912-415-117-65-118-811-013-615-7
Spruce-pine-fir #26-69-912-415-117-65-118-811-013-615-7
Spruce-pine-fir #35-07-49-411-513-24-66-78-410-211-10
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
b. Span exceeds 26 feet in length.
(Effective January 1, 2015)

TABLE R802.5.1(6)
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=50 psf, ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)
12Douglas fir-larch SS7-812-115-1120-324-87-812-115-1120-324-0
Douglas fir-larch #17-511-715-318-721-77-511-214-117-320-0
Douglas fir-larch #27-311-314-317-520-27-110-513-216-118-8
Douglas fir-larch #35-108-610-913-215-35-57-1010-012-214-1
Hem-fir SS7-311-515-019-223-47-311-515-019-223-4
Hem-fir #17-111-214-818-121-07-110-1013-916-919-5
Hem-fir #26-910-814-017-219-116-910-313-015-1018-5
Hem-fir #35-108-610-913-215-35-57-1010-012-214-1
Southern pine SS 7-6 11-10 15-7 19-11 24-3 7-6 11-10 15-7 19-11 24-3
Southern pine #1 7-3 11-5 15-0 18-2 21-7 7-3 11-4 14-5 16-10 20-0
Southern pine #2 6-11 10-6 13-4 15-10 18-8 6-6 9-9 12-4 14-8 17-3
Southern pine #3 5-5 8-0 10-1 12-3 14-6 5-0 7-5 9-4 11-4 13-5
Spruce-pine-fir SS7-111-214-818-922-107-111-214-818-922-4
Spruce-pine-fir #16-1110-1114-317-520-26-1110-513-216-118-8
Spruce-pine-fir #26-1110-1114-317-520-26-1110-513-216-118-8
Spruce-pine-fir #35-108-610-913-215-35-57-1010-012-214-1
16Douglas fir-larch SS7-011-014-518-522-57-011-014-517-1120-10
Douglas fir-larch #16-910-513-216-118-86-79-812-214-1117-3
Douglas fir-larch #26-79-912-415-117-66-29-011-513-1116-2
Douglas fir-larch #35-07-49-411-513-24-86-108-810-612-3
Hem-fir SS6-710-413-817-521-26-710-413-817-520-5
Hem-fir #16-510-212-1015-818-26-59-511-1114-616-10
Hem-fir #26-29-712-214-1017-36-18-1111-313-915-11
Hem-fir #35-07-49-411-513-24-86-108-810-612-3
Southern pine SS 6-10 10-9 14-2 18-1 22-0 6-10 10-9 14-2 18-1 22-10
Southern pine #1 6-7 10-4 13-5 15-9 18-8 6-7 9-10 12-5 14-7 17-3
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-8 8-5 10-9 12-9 15-0
Southern pine #3 4-8 6-11 8-9 10-7 12-6 4-4 6-5 8-1 9-10 11-7
Spruce-pine-fir SS6-510-213-417-020-96-510-213-416-819-4
Spruce-pine-fir #16-49-912-415-117-66-29-011-513-1116-2
Spruce-pine-fir #26-49-912-415-117-66-29-011-513-1116-2
Spruce-pine-fir #35-07-49-411-513-24-86-108-810-612-3
19.2Douglas fir-larch SS6-710-413-717-420-66-710-413-516-519-0
Douglas fir-larch #16-49-612-014-817-16-08-1011-213-715-9
Douglas fir-larch #26-18-1111-313-915-115-78-310-512-914-9
Douglas fir-larch #34-76-98-610-512-14-36-37-119-711-2
Hem-fir SS6-29-912-1016-519-116-29-912-1016-118-8
Hem-fir #16-19-311-914-416-75-108-710-1013-315-5
Hem-fir #25-98-911-113-715-95-78-110-312-714-7
Hem-fir #34-76-98-610-512-14-36-37-119-711-2

(continiued)

TABLE R802.5.1(6)—continued
RAFTER SPANS FOR COMMON LUMBER SPECIES
(Ground snow load=50 psf, ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)
19.2Southern pine SS 6-5 10-2 13-4 17-0 20-9 6-5 10-2 13-4 16-11 20-0
Southern pine #1 6-2 9-8 12-3 14-4 17-1 6-0 9-0 11-4 13-4 15-9
Southern pine #2 5-7 8-4 10-7 12-6 14-9 5-2 7-9 9-9 11-7 13-8
Southern pine #3 4-3 6-4 8-0 9-8 11-5 4-0 5-10 7-4 8-11 10-7
Spruce-pine-fir SS 6-1 9-6 12-7 16-0 19-1 6-1 9-6 12-5 15-3 17-8
Spruce-pine-fir #15-118-1111-313-915-115-78-310-512-914-9
Spruce-pine-fir #25-118-1111-313-915-115-78-310-512-914-9
Spruce-pine-fir #34-76-98-610-512-14-36-37-119-711-2
24Douglas fir-larch SS6-19-712-715-1018-46-19-612-014-817-0
Douglas fir-larch #15-108-610-913-215-35-57-1010-012-214-1
Douglas fir-larch #25-57-1110-112-414-35-07-49-411-513-2
Douglas fir-larch #34-16-07-79-410-93-105-77-18-710-0
Hem-fir SS5-99-111-1115-218-05-99-111-914-515-11
Hem-fir #15-88-310-612-1014-105-37-89-911-1013-9
Hem-fir #25-47-109-1112-114-14-117-39-211-313-0
Hem-fir #34-16-07-79-410-93-105-77-18-710-0
Southern pine SS 6-0 9-5 12-5 15-10 19-3 6-0 9-5 12-5 15-2 17-10
Southern pine #1 5-9 8-8 11-0 12-10 15-3 5-5 8-0 10-2 11-11 14-1
Southern pine #2 5-0 7-5 9-5 11-3 13-2 4-7 6-11 8-9 10-5 12-3
Southern pine #3 3-10 5-8 7-1 8-8 10-3 3-6 5-3 6-7 8-0 9-6
Spruce-pine-fir SS 5-8 8-10 11-8 14-8 17-1 5-8 8-10 11-2 13-7 15-9
Spruce-pine-fir #15-57-1110-112-414-35-07-49-411-513-2
Spruce-pine-fir #25-57-1110-112-414-35-07-49-411-513-2
Spruce-pine-fir #34-16-07-79-410-93-105-77-18-710-0
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
(Effective January 1, 2015)

TABLE R802.5.1(7)
RAFTER SPANS FOR 70 PSF GROUND SNOW LOAD
(Ceiling not attached to rafters, L/Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum Rafter Spansa
(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)
12Douglas fir-larch SS7-711-1015-819-522-67-711-1015-018-321-2
Douglas fir-larch #17-110-513-216-118-86-89-1012-515-217-7
Douglas fir-larch #26-89-912-415-117-66-39-211-814-216-6
Douglas fir-larch #35-07-49-411-513-24-96-118-910-912-5
Hem-fir SS7-211-314-918-1022-17-211-314-818-020-10
Hem-fir #16-1110-212-1015-818-26-69-712-114-1017-2
Hem-fir #26-79-712-214-1017-36-29-111-514-016-3
Hem-fir #35-07-49-411-513-24-96-118-910-912-5
Southern pine SS 7-5 11-8 15-4 19-7 23-7 7-5 11-8 15-4 18-10 22-3
Southern pine #1 7-1 10-7 13-5 15-9 18-8 6-9 10-0 12-8 14-10 17-7
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-9 8-7 10-11 12-11 15-3
Southern pine #3 4-8 6-11 8-9 10-7 12-6 4-5 6-6 8-3 10-0 11-10
Spruce-pine-fir SS7-011-014-618-020-117-011-013-1117-019-8
Spruce-pine-fir #16-89-912-415-117-66-39-211-814-216-6
Spruce-pine-fir #26-89-912-415-117-66-39-211-814-216-6
Spruce-pine-fir #35-07-49-411-513-24-96-118-910-912-5
16Douglas fir-larch SS6-1010-913-916-1019-66-1010-313-015-1018-4
Douglas fir-larch #16-29-011-513-1116-25-108-610-913-215-3
Douglas fir-larch #25-98-510-813-115-25-57-1110-112-414-3
Douglas fir-larch #34-46-48-19-1011-54-16-07-79-410-9
Hem-fir SS6-610-213-516-619-26-610-112-915-718-0
Hem-fir #16-08-911-213-715-95-88-310-612-1014-10
Hem-fir #25-88-410-612-1014-115-47-109-1112-114-1
Hem-fir #34-46-48-19-1011-54-16-07-79-410-9
Southern pine SS 6-9 10-7 14-0 17-4 20-5 6-9 10-7 13-9 16-4 19-3
Southern pine #1 6-2 9-2 11-8 13-8 16-2 5-10 8-8 11-0 12-10 15-3
Southern pine #2 5-3 7-11 10-0 11-11 14-0 5-0 7-5 9-5 11-3 13-2
Southern pine #3 4-1 6-0 7-7 9-2 10-10 3-10 5-8 7-1 8-8 10-3
Spruce-pine-fir SS6-410-012-915-718-16-49-612-014-817-1
Spruce-pine-fir #15-98-510-813-115-25-57-1110-112-414-3
Spruce-pine-fir #25-98-510-813-115-25-57-1110-112-414-3
Spruce-pine-fir #34-46-48-19-1011-54-16-07-79-410-9
19.2Douglas fir-larch SS6-59-1112-715-417-96-59-411-1014-516-9
Douglas fir-larch #15-78-310-512-914-95-47-99-1012-013-11
Douglas fir-larch #25-37-89-911-1113-105-07-39-211-313-0
Douglas fir-larch #34-05-107-49-010-53-95-66-118-69-10
Hem-fir SS6-19-712-415-117-46-19-211-814-215-5
Hem-fir #15-68-010-212-514-55-27-79-711-813-7
Hem-fir #25-27-79-711-913-74-117-29-111-112-10
Hem-fir #34-05-107-49-010-53-95-66-118-69-10

(continued)

TABLE R802.5.1(7)—continued
RAFTER SPANS FOR 70 PSF GROUND SNOW LOAD
(Ceiling not attached to rafters, L/
Δ = 180)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum Rafter Spansa
(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)(feet- inches)
19.2Southern pine SS 6-4 10-0 13-2 15-10 18-8 6-4 9-10 12-6 14-11 17-7
Southern pine #1 5-8 8-5 10-8 12-5 14-9 5-4 7-11 10-0 11-9 13-11
Southern pine #2 4-10 7-3 9-2 10-10 12-9 4-6 6-10 8-8 10-3 12-1
Southern pine #3 3-8 5-6 6-11 8-4 9-11 3-6 5-2 6-6 7-11 9-4
Spruce-pine-fir SS6-09-211-814-316-65-118-811-013-515-7
Spruce-pine-fir #15-37-89-911-1113-105-07-39-211-313-0
Spruce-pine-fir #25-37-89-911-1113-105-07-39-211-313-0
Spruce-pine-fir #34-05-107-49-010-53-95-66-118-69-10
24Douglas fir-larch SS6-08-1011-313-915-115-98-410-712-1115-0
Douglas fir-larch #15-07-49-411-513-24-96-118-910-912-5
Douglas fir-larch #24-86-118-910-812-44-56-68-310-011-8
Douglas fir-larch #33-75-26-78-19-43-44-116-37-78-10
Hem-fir SS5-88-811-013-613-115-78-310-512-412-4
Hem-fir #14-117-29-111-112-104-76-98-710-612-2
Hem-fir #24-86-98-710-612-24-46-58-19-1111-6
Hem-fir #33-75-26-78-19-43-44-116-37-78-10
Southern pine SS 5-11 9-3 11-11 14-2 16-8 5-11 8-10 11-2 13-4 15-9
Southern pine #1 5-0 7-6 9-6 11-1 13-2 4-9 7-1 9-0 10-6 12-5
Southern pine #2 4-4 6-5 8-2 9-9 11-5 4-1 6-1 7-9 9-2 10-9
Southern pine #3 3-4 4-11 6-2 7-6 8-10 3-1 4-7 5-10 7-1 8-4
Spruce-pine-fir SS5-68-310-512-914-95-47-99-1012-012-11
Spruce-pine-fir #14-86-118-910-812-44-56-68-310-011-8
Spruce-pine-fir #24-86-118-910-812-44-56-68-310-011-8
Spruce-pine-fir #33-75-26-78-19-43-44-116-37-78-10
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
(Effective January 1, 2015)

TABLE R802.5.1(8)
RAFTER SPANS FOR 70 PSF GROUND SNOW LOAD
(Ceiling attached to rafters, L/
Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
12Douglas fir-larch SS6-1010-914-318-222-16-1010-914-318-221-2
Douglas fir-larch #16-710-513-216-118-86-79-1012-515-217-7
Douglas fir-larch #26-69-912-415-117-66-39-211-814-216-6
Douglas fir-larch #35-07-49-411-513-24-96-118-910-912-5
Hem-fir SS6-610-213-517-220-106-610-213-517-220-10
Hem-fir #16-410-012-1015-818-26-49-712-114-1017-2
Hem-fir #26-19-612-214-1017-36-19-111-514-016-3
Hem-fir #35-07-49-411-513-24-96-118-910-912-5
Southern pine SS 6-9 10-7 14-0 17-10 21-8 6-9 10-7 14-0 17-10 21-8
Southern pine #1 6-6 10-2 13-5 15-9 18-8 6-6 10-0 12-8 14-10 17-7
Southern pine #2 6-1 9-2 11-7 13-9 16-2 5-9 8-7 10-11 12-11 15-3
Southern pine #3 4-8 6-11 8-9 10-7 12-6 4-5 6-6 8-3 10-0 11-10
Spruce-pine-fir SS6-410-013-216-920-56-410-013-216-919-8
Spruce-pine-fir #16-29-912-415-117-66-29-211-814-216-6
Spruce-pine-fir #26-29-912-415-117-66-29-211-814-216-6
Spruce-pine-fir #35-07-49-411-513-24-96-118-910-912-5
16Douglas fir-larch SS6-39-1012-1116-619-66-39-1012-1115-1018-4
Douglas fir-larch #16-09-011-513-1116-25-108-610-913-215-3
Douglas fir-larch #25-98-510-813-115-25-57-1110-112-414-3
Douglas fir-larch #34-46-48-19-1011-54-16-07-79-410-9
Hem-fir SS5-119-312-215-718-115-119-312-215-718-0
Hem-fir #15-98-911-213-715-95-88-310-612-1014-10
Hem-fir #25-68-410-612-1014-115-47-109-1112-114-1
Hem-fir #34-46-48-19-1011-54-16-07-79-410-9
Southern pine SS 6-1 9-7 12-8 16-2 19-8 6-1 9-7 12-8 16-2 19-8
Southern pine #1 5-11 9-2 11-8 13-8 16-2 5-10 8-8 11-0 12-10 15-3
Southern pine #2 5-3 7-11 10-0 11-11 14-0 5-0 7-5 9-5 11-3 13-2
Southern pine #3 4-1 6-0 7-7 9-2 10-10 3-10 5-8 7-1 8-8 10-3
Spruce-pine-fir SS5-99-111-1115-318-15-99-111-1114-817-1
Spruce-pine-fir #15-88-510-813-115-25-57-1110-112-414-3
Spruce-pine-fir #25-88-510-813-115-25-57-1110-112-414-3
Spruce-pine-fir #34-46-48-19-1011-54-16-07-79-410-9
19.2Douglas fir-larch SS5-109-312-215-417-95-109-311-1014-516-9
Douglas fir-larch #15-78-310-512-914-95-47-99-1012-013-11
Douglas fir-larch #25-37-89-911-1113-105-07-39-211-313-0
Douglas fir-larch #34-05-107-49-010-53-95-66-118-69-10
Hem-fir SS5-68-811-614-817-45-68-811-614-215-5
Hem-fir #15-58-010-212-514-55-27-79-711-813-7
Hem-fir #25-27-79-711-913-74-117-29-111-112-10
Hem-fir #34-05-107-49-010-53-95-66-118-69-10

(continued)

TABLE R802.5.1(8)—continued
RAFTER SPANS FOR 70 PSF GROUND SNOW LOAD
(Ceiling attached to rafters, L/Δ = 240)

RAFTER
SPACING
(inches)
SPECIES AND GRADEDEAD LOAD = 10 psfDEAD LOAD = 20 psf
2 × 42 × 62 × 82 × 102 × 122 × 42 × 62 × 82 × 102 × 12
Maximum rafter spansa
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
(feet -
inches)
19.2Southern pine SS 5-9 9-1 11-11 15-3 18-6 5-9 9-1 11-11 14-11 17-7
Southern pine #1 5-6 8-5 10-8 12-5 14-9 5-4 7-11 10-0 11-9 13-11
Southern pine #2 4-10 7-3 9-2 10-10 12-9 4-6 6-10 8-8 10-3 12-1
Southern pine #3 3-8 5-6 6-11 8-4 9-11 3-6 5-2 6-6 7-11 9-4
Spruce-pine-fir SS5-58-611-314-316-65-58-611-013-515-7
Spruce-pine-fir #15-37-89-911-1113-105-07-39-211-313-0
Spruce-pine-fir #25-37-89-911-1113-105-07-39-211-313-0
Spruce-pine-fir #34-05-107-49-010-53-95-66-118-69-10
24Douglas fir-larch SS5-58-711-313-915-115-58-410-712-1115-0
Douglas fir-larch #15-07-49-411-513-24-96-118-910-912-5
Douglas fir-larch #24-86-118-910-812-44-56-68-310-011-8
Douglas fir-larch #33-75-26-78-19-43-44-116-37-78-10
Hem-fir SS5-28-110-813-613-115-28-110-512-412-4
Hem-fir #14-117-29-111-112-104-76-98-710-612-2
Hem-fir #24-86-98-710-612-24-46-58-19-1111-6
Hem-fir #33-75-26-78-19-43-44-116-37-78-10
Southern pine SS 5-4 8-5 11-1 14-2 16-8 5-4 8-5 11-1 13-4 15-9
Southern pine #1 5-0 7-6 9-6 11-1 13-2 4-9 7-1 9-0 10-6 12-5
Southern pine #2 4-4 6-5 8-2 9-9 11-5 4-1 6-1 7-9 9-2 10-9
Southern pine #3 3-4 4-11 6-2 7-6 8-10 3-1 4-7 5-10 7-1 8-4
Spruce-pine-fir SS5-07-1110-512-914-95-07-99-1012-012-11
Spruce-pine-fir #14-86-118-910-812-44-56-68-310-011-8
Spruce-pine-fir #24-86-118-910-812-44-56-68-310-011-8
Spruce-pine-fir #33-75-26-78-19-43-44-116-37-78-10
Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the bearing walls, such as rafter ties, is provided at that location. When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below:
HC/HRRafter Span Adjustment Factor
1/30.67
1/40.76
1/50.83
1/60.90
1/7.5 or less1.00
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
(Effective January 1, 2015)

TABLE R802.5.1(9)
RAFTER/CEILING JOIST HEEL JOINT CONNECTIONSa, b, c, d, e, f, h

RAFTER
SLOPE
RAFTER
SPACING
(inches)
GROUND SNOW LOAD (psf)
20g3050 70
Roof span (feet)
12202836122028361220283612202836
Required number of 16d common nailsa, b per heel joint splicesc, d, e, f
3:121246810468115812156111520
1658101358111461115208142026
2471115197111621916233012213039
4:12123568356846911581215
1646810468115812156111520
2458121559121671217229162329
5:121234563457357947912
163568357947912591216
244791247101361014187131823
7:12123445334534573579
1634563456357946911
2435793579471013591317
9:12123344333433453457
163445334534573579
243467346736810471013
12:12123333333333343345
163344333433453457
2434453346346836810
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. 40d box nails shall be permitted to be substituted for 16d common nails.
b. Nailing requirements shall be permitted to be reduced 25 percent if nails are clinched.
c. Heel joint connections are not required when the ridge is supported by a load-bearing wall, header or ridge beam.
d. When intermediate support of the rafter is provided by vertical struts or purlins to a load-bearing wall, the tabulated heel joint connection requirements shall be permitted to be reduced proportionally to the reduction in span.
e. Equivalent nailing patterns are required for ceiling joist to ceiling joist lap splices.
f. When rafter ties are substituted for ceiling joists, the heel joint connection requirement shall be taken as the tabulated heel joint connection requirement for two-thirds of the actual rafter slope.
g. Applies to roof live load of 20 psf or less.
h. Tabulated heel joint connection requirements assume that ceiling joists or rafter ties are located at the bottom of the attic space. When ceiling joists or rafter ties are located higher in the attic, heel joint connection requirements shall be increased by the following factors:
HC/HRHeel Joint Connection Adjustment Factor
1/31.5
1/41.33
1/51.25
1/61.2
1/10 or less1.11
where:
HC = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls.
HR = Height of roof ridge measured vertically above the top of the rafter support walls.
For SI: 1 inch = 25.4 mm, 1 foot = 305 mm, 1 degree = 0.018 rad.
Note: Where ceiling joists run perpendicular to the rafter, rafter ties shall be installed in accordance with Section R802.3.1.
HC = Height of ceiling joists or rafter ties measured vertically above the top of rafter support walls.
HR= Height of roof ridge measured vertically above the top of the rafter support walls.

FIGURE R802.5.1
BRACED RAFTER CONSTRUCTION
(Effective January 1, 2015)

The ends of each rafter or ceiling joist shall have not less than 11/2 inches (38 mm) of bearing on wood or metal and not less than 3 inches (76 mm) on masonry or concrete. The bearing on masonry or concrete shall be direct, or a sill plate of 2-inch (51 mm) minimum nominal thickness shall be provided under the rafter or ceiling joist. The sill plate shall provide a minimum nominal bearing area of 48 square inches (30 865 mm2).
If the finished ceiling material is installed on the ceiling prior to the attachment of the ceiling to the walls, such as in construction at a factory, a compression strip of the same thickness as the finish ceiling material shall be installed directly above the top plate of bearing walls if the compressive strength of the finish ceiling material is less than the loads it will be required to withstand. The compression strip shall cover the entire length of such top plate and shall be at least one-half the width of the top plate. It shall be of material capable of transmitting the loads transferred through it.
Structural roof members shall not be cut, bored or notched in excess of the limitations specified in this section.
Cuts, notches, and holes in solid lumber joists, rafters, blocking and beams shall comply with the provisions of R502.8.1 except that cantilevered portions of rafters shall be permitted in accordance with Section R802.7.1.1.
Notches on cantilevered portions of rafters are permitted provided the dimension of the remaining portion of the rafter is not less than 31/2 inches (89 mm) and the length of the cantilever does not exceed 24 inches (610 mm) in accordance with Figure R802.7.1.1.
For SI: 1 inch = 25.4 mm.

FIGURE R802.7.1.1
RAFTER NOTCH

Taper cuts at the ends of the ceiling joist shall not exceed one-fourth the depth of the member in accordance with Figure R802.7.1.2.

FIGURE R802.7.1.2
CEILING JOIST TAPER CUT

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.
Roof framing members and ceiling joists having a depth-to-thickness ratio exceeding 5 to 1 based on nominal dimensions shall be provided with lateral support at points of bearing to prevent rotation. For roof rafters with ceiling joists attached per Table R602.3(1), the depth-to-thickness ratio for the total assembly shall be determined using the combined thickness of the rafter plus the attached ceiling joist.
Exception: Roof trusses shall be braced in accordance with Section R802.10.3.
Rafters and ceiling joists having a depth-to-thickness ratio exceeding 6 to 1 based on nominal dimensions shall be supported laterally by solid blocking, diagonal bridging (wood or metal) or a continuous 1-inch by 3-inch (25 mm by 76 mm) wood strip nailed across the rafters or ceiling joists at intervals not exceeding 8 feet (2438 mm).
Openings in roof and ceiling framing shall be framed with 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 ceiling joist or rafter. 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 ceiling joists or rafter 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).
Truss design drawings, prepared in conformance to Section R802.10.1, shall be provided to the building official and approved prior to installation. Truss design drawings shall include, at a minimum, the information specified below. Truss design drawings shall be provided with the shipment of trusses delivered to the jobsite.
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 (as determined from Section R301.6).
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.
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 gage) 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.
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 design drawing or on supplemental documents.
12. Required permanent truss member bracing location.
Wood trusses shall be designed in accordance with accepted 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.
The provisions of this section shall control the design of truss roof framing when snow controls for buildings not greater than 60 feet (18 288 mm) in length perpendicular to the joist, rafter or truss span, not greater than 36 feet (10 973 mm) in width parallel to the joist, rafter or truss span, not more than three stories above grade plane in height, and roof slopes not smaller than 3:12 (25 percent slope) or greater than 12:12 (100 percent slope). Truss roof 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 A, B or C, and a maximum ground snow load of 70 psf (3352 Pa). For consistent loading of all truss types, roof snow load is to be computed as: 0.7 pg.
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 practice 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 shall not be cut, notched, drilled, 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) that exceeds the design load for the truss shall not be permitted without verification that the truss is capable of supporting such additional loading. Deleted

R802.11 Roof Tie-Down

STATE AMENDMENT

TABLE R802.11
RAFTER OR TRUSS UPLIFT CONNECTION FORCES FROM WIND (POUNDS PER CONNECTION)a, b, c, d, e, f, g, h,i

RAFTER OR
TRUSS
SPACING
ROOF SPAN
(feet)
EXPOSURE B
Basic Wind Speed (mph)
8590100110
Roof PitchRoof PitchRoof PitchRoof Pitch
< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12
12″ o.c.12474162549381127110
1859517868119104165144
2470619381145126202176
28776710490163142227197
328574115100180157252219
369381126110198172277241
4210591143124225196315274
48116101159138251218353307
16″ o.c.1263558372124108169147
18786810390159138219191
249381124108193168269234
2810289138120217189302263
3211398153133239208335291
36124108168146264230369321
42139121190165299260420365
48155135212184335291471410
24″ o.c.129482124108186162254221
18117102155135238207329286
24140122186162290252404351
28154134208181326284454395
32170148230200360313504438
36186162252219396345554482
42209182285248449391630548
48232202318277502437706614
RAFTER OR TRUSS SPACINGROOF SPAN (feet)EXPOSURE C
Basic Wind Speed (mph)
8590100110
Roof PitchRoof PitchRoof PitchRoof Pitch
< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12
12″ o.c.12948211499157137206179
18120104146127204177268233
24146127179156251218330287
28164143201175283246372324
32182158224195314273414360
36200174246214346301456397
42227197279243394343520452
48254221313272441384583507

(continued)

TABLE R802.11—continued
RAFTER OR TRUSS UPLIFT CONNECTION FORCES FROM WIND (POUNDS PER CONNECTION)a, b, c, d, e, f, g, h,i

RAFTER OR
TRUSS
SPACING
ROOF SPAN (feet)EXPOSURE C
Basic Wind Speed (mph)
8590100110
Roof PitchRoof PitchRoof PitchRoof Pitch
< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12< 5:12≥ 5:12
16″ o.c.12125109152132209182274238
18160139194169271236356310
24194169238207334291439382
28218190267232376327495431
32242211298259418364551479
36266231327284460400606527
42302263372324524456691601
48338294416362587511775674
24″ o.c.12188164228198314273412358
18240209292254408355536466
24292254358311502437660574
28328285402350566492744647
32364317448390628546828720
36400348492428692602912793
424543955584857866841040905
4850844262654588276711661014
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound = 0.454 kg, 1 pound per linear foot = 14.5 N/m.
a. The uplift connection forces are based on a maximum 33-foot mean roof height and Wind Exposure Category B or C. For Exposure D, the uplift connection force shall be selected from the Exposure C portion of the table using the next highest tabulated basic wind speed. The Adjustment Coefficients in Table R301.2(3) shall not be used to multiply the above forces for Exposures C and D or for other mean roof heights.
b. The uplift connection forces include an allowance for roof and ceiling assembly dead load of 15 psf.
c. The tabulated uplift connection forces are limited to a maximum roof overhang of 24 inches.
d. The tabulated uplift connection forces shall be permitted to be multiplied by 0.75 for connections not located within 8 feet of building corners.
e. For buildings with hip roofs with 5:12 and greater pitch, the tabulated uplift connection forces shall be permitted to be multiplied by 0.70. This reduction shall not be combined with any other reduction in tabulated forces.
f. For wall-to-wall and wall-to-foundation connections, the uplift connection force shall be permitted to be reduced by 60 plf for each full wall above.
g. Linear interpolation between tabulated roof spans and wind speeds shall be permitted.
h. The tabulated forces for a 12-inch on-center spacing shall be permitted to be used to determine the uplift load in pounds per linear foot.
i. A valid code evaluation report from an approved agency may be used to determine the equivalent sizes of power driven type fasteners, subject to final approval of the local building official.
(Effective January 1, 2014)
Roof assemblies shall have uplift resistance in accordance with Sections R802.11.1.2 and R802.11.1.3.
Where the uplift force does not exceed 200 pounds, rafters and trusses spaced not more than 24 inches (610 mm) on center shall be permitted to be attached to their supporting wall assemblies in accordance with Table R602.3(1).
Where the basic wind speed does not exceed 90 mph, the wind exposure category is B, the roof pitch is 5:12 or greater, and the roof span is 32 feet (9754 mm) or less, rafters and trusses spaced not more than 24 inches (610 mm) on center shall be permitted to be attached to their supporting wall assemblies in accordance with Table R602.3(1).
Trusses shall be attached to supporting wall assemblies by connections capable of resisting uplift forces as specified on the truss design drawings. Uplift forces shall be permitted to be determined as specified by Table R802.11, if applicable, or as determined by accepted engineering practice.
Individual rafters shall be attached to supporting wall assemblies by connections capable of resisting uplift forces as determined by Table R802.11 or as determined by accepted engineering practice. Connections for beams used in a roof system shall be designed in accordance with accepted engineering practice.
Allowable spans for lumber used as roof sheathing shall conform to Table R803.1. Spaced lumber sheathing for wood shingle and shake roofing shall conform to the requirements of Sections R905.7 and R905.8. Spaced lumber sheathing is not allowed in Seismic Design Category D2.

TABLE R803.1
MINIMUM THICKNESS OF LUMBER ROOF SHEATHING

RAFTER OR BEAM SPACING
(inches)
MINIMUM NET THICKNESS
(inches)
245/8
48a11/2 T & G
60b
72c
For SI: 1 inch = 25.4 mm.
a. Minimum 270 Fb, 340,000 E.
b. Minimum 420 Fb, 660,000 E.
c. Minimum 600Fb, 1,150,000 E.
Wood structural panels shall conform to DOC PS 1, DOC PS 2 or, when manufactured in Canada, CSA O437 or CSA O325, and shall be identified for grade, bond classification, and Performance Category by a grade mark or certificate of inspection issued by an approved agency. Wood structural panels shall comply with the grades specified in Table R503.2.1.1(1).
All wood structural panels, when designed to be permanently exposed in outdoor applications, shall be of an exterior exposure durability. Wood structural panel roof sheathing exposed to the underside may be of interior type bonded with exterior glue, identified as Exposure 1.
The allowable unit stresses for fire-retardant-treated plywood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated plywood will be subjected, the type of treatment and redrying process. The fire-retardant-treated plywood shall be graded by an approved agency.
The maximum allowable spans for wood structural panel roof sheathing shall not exceed the values set forth in Table R503.2.1.1(1), or APA E30.
Wood structural panel used as roof sheathing shall be installed with joints staggered or not staggered in accordance with Table R602.3(1), or APA E30 for wood roof framing or with Table R804.3 for steel roof framing.
Elements shall be straight and free of any defects that would significantly affect their structural performance. Cold-formed steel roof framing members shall comply with the requirements of this section.
The provisions of this section shall control the construction of cold-formed steel roof framing for buildings not greater than 60 feet (18 288 mm) perpendicular to the joist, rafter or truss span, not greater than 40 feet (12 192 mm) in width parallel to the joist span or truss, less than or equal to three stories above grade plane and with roof slopes not less than 3:12 (25-percent slope) or greater than 12:12 (100-percent slope). Cold-formed steel roof 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 (3350 Pa).