International Building Code Section 2306

International Building Code 2306.1

Allowable stress design. The structural analysis and
construction of wood elements in structures using allowable
stress design shall be in accordance with the following applicable
standards:
American Forest & Paper Association.
NDS NationalDesign Specification forWoodConstruction
American Institute of Timber Construction.
AITC 104 Typical Construction Details
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WOOD
AITC 110 Standard Appearance Grades for Structural
Glued Laminated Timber
AITC 113 Standard for Dimensions of Structural Glued
Laminated Timber
AITC 117 Standard Specifications for Structural Glued
Laminated Timber of Softwood Species
AITC 119 Structural Standard Specifications for Glued
Laminated Timber of Hardwood Species
AITC A190.1 Structural Glued Laminated Timber
AITC 200 Inspection Manual
American Society of Agricultural Engineers.
ASAE EP 484.2 Diaphragm Des ign of Metal -Clad,
Post-Frame Rectangular Buildings
ASAE EP 486.1 Shallow Post Foundation Design
ASAE 559 Design Requirements and Bending Properties
for Mechanically Laminated Columns
APA-The Engineered Wood Association.
Panel Design Specification
Plywood Design Specification Supplement 1 -
Design & Fabrication of Plywood Curved Panel
Plywood Design Specification Supplement 2 -
Design & Fabrication of Glued Plywood-Lumber Beams
Plywood Design Specification Supplement 3 -
Design & Fabrication of Plywood Stressed-Skin Panels
Plywood Design Specification Supplement 4 -
Design & Fabrication of Plywood Sandwich Panels
Plywood Design Specification Supplement 5 -
Design & Fabrication of All-Plywood Beams
EWS T300 Glulam Connection Details
EWS S560 Field Notching and Drilling of Glued Laminated
Timber Beams
EWS S475 Glued Laminated Beam Design Tables
EWS X450 Glulam in Residential Construction
EWS X440 Product and Application Guide: Glulam
EWS R540 Builders Tips: Proper Storage and Handling of
Glulam Beams
Truss Plate Institute, Inc.
TPI 1 National Design Standard for Metal Plate Connected
Wood Truss Construction

Joists and rafters. The design of rafter spans is
permitted to be in accordance with the AF&PA Span Tables
for Joists and Rafters.

Plank and beam flooring. The design of plank
and beam flooring is permitted to be in accordance with the
AF&PA Wood Construction Data No. 4.

Treatedwood stress adjustments. The allowable
unit stresses for preservative-treated wood need no adjustment
for treatment, but are subject to other adjustments.
The allowable unit stresses for fire-retardant-treated
wood, 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 wood will be subjected, the type of
treatment and the redrying process. Other adjustments are
applicable except that the impact load duration shall not
apply.

Lumber decking. The capacity of lumber decking
arranged according to the patterns described in Section
2304.8.2 shall be the lesser of the capacities determined for
flexure and deflection according to the formulas in Table
2306.1.4.

International Building Code 2306.1.1

Joists and rafters. The design of rafter spans is
permitted to be in accordance with the AF&PA Span Tables
for Joists and Rafters.

International Building Code 2306.1.2

Plank and beam flooring. The design of plank
and beam flooring is permitted to be in accordance with the
AF&PA Wood Construction Data No. 4.

International Building Code 2306.1.3

Treatedwood stress adjustments. The allowable
unit stresses for preservative-treated wood need no adjustment
for treatment, but are subject to other adjustments.
The allowable unit stresses for fire-retardant-treated
wood, 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 wood will be subjected, the type of
treatment and the redrying process. Other adjustments are
applicable except that the impact load duration shall not
apply.

International Building Code 2306.1.4

Lumber decking. The capacity of lumber decking
arranged according to the patterns described in Section
2304.8.2 shall be the lesser of the capacities determined for
flexure and deflection according to the formulas in Table
2306.1.4.

International Building Code 2306.2

Wind provisions for walls.

Wall stud bending stress increase. The AF&PA
NDS fiber stress in bending (Fb) design values for sawn
lumberwood studs resisting out of plane wind loads shall be
increased by the factors in Table 2306.2.1, in lieu of the 1.15
repetitive member factor. These increases take into consideration
the load sharing and composite actions provided by
thewood structural panels as defined in Section 2302.1. The
increases shall apply where the studs are designed for bending
and are spaced no more than 16 inches (406 mm) o.c.,covered on the inside with a minimum of 1/2-inch (12.7 mm)
gypsum board fastened in accordance with Table 2306.4.5
and sheathed on the exterior with a minimum of 3/8-inch (9.5
mm) wood structural panel sheathing. All panel joints shall
occur over studs or blocking and shall be attached using a
minimum of 8d common nails spaced a maximum of 6
inches o.c. (152 mm) at panel edges and 12 inches o.c. (305
mm) at intermediate framing members.

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International Building Code 2306.2.1

Wall stud bending stress increase. The AF&PA
NDS fiber stress in bending (Fb) design values for sawn
lumberwood studs resisting out of plane wind loads shall be
increased by the factors in Table 2306.2.1, in lieu of the 1.15
repetitive member factor. These increases take into consideration
the load sharing and composite actions provided by
thewood structural panels as defined in Section 2302.1. The
increases shall apply where the studs are designed for bending
and are spaced no more than 16 inches (406 mm) o.c.,covered on the inside with a minimum of 1/2-inch (12.7 mm)
gypsum board fastened in accordance with Table 2306.4.5
and sheathed on the exterior with a minimum of 3/8-inch (9.5
mm) wood structural panel sheathing. All panel joints shall
occur over studs or blocking and shall be attached using a
minimum of 8d common nails spaced a maximum of 6
inches o.c. (152 mm) at panel edges and 12 inches o.c. (305
mm) at intermediate framing members.

2006 INTERNATIONAL BUILDING CODE 443
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International Building Code 2306.3

Wood diaphragms.

Wood structural panel diaphragms. Wood
structural panel diaphragms are permitted to resist horizontal
forces using the allowable shear capacities set forth in
Table 2306.3.1 or 2306.3.2. The allowable shear capacities
are permitted to be calculated by principles of mechanics
without limitations by using values for fastener strength in
the AF&PA NDS, structural design properties for wood
structural panels based on DOC PS-1 and DOC PS-2 or
wood structural panel design properties given in the APA
Panel Design Specification (PDS).

Shear capacities modifications. The allowable
shear capacities in Tables 2306.3.1 and 2306.3.2 for horizontal
wood structural panel diaphragms shall be increased
40 percent for wind design.

Diagonally sheathed lumber diaphragms.
Diagonally sheathed lumber diaphragms shall be nailed in
accordance with Table 2306.3.3.

Single diagonally sheathed lumber diaphragms.
Single diagonally sheathed lumber diaphragms
shall be constructed of minimum 1-inch (25 mm) thick
nominal sheathing boards laid at an angle of approximately
45 degrees (0.78 rad) to the supports. The shear capacity for
single diagonally sheathed lumber diaphragms of southern
pine or Douglas fir-larch shall not exceed 300 plf (4378
N/m) of width. The shear capacities shall be adjusted by
reduction factors of 0.82 for framing members of species
with a specific gravity equal to or greater than 0.42 but less
than 0.49 and 0.65 for species with a specific gravity of less
than 0.42, as contained in the AF&PA NDS.

End joints. End joints in adjacent boards
shall be separated by at least one stud or joist space and
there shall be at least two boards between joints on the
same support.

Single diagonally sheathed lumber diaphragms.
Single diagonally sheathed lumber diaphragms
made up of 2-inch (51 mm) nominal diagonal
lumber sheathing fastened with 16d nails shall be
designed with the same shear capacities as shear panels
using 1-inch (25 mm) boards fastened with 8d nails, provided
there are not splices in adjacent boards on the same
support and the supports are not less than 4 inch (102
mm) nominal depth or 3 inch (76 mm) nominal thickness.

Double diagonally sheathed lumber diaphragms.
Double diagonally sheathed lumber diaphragms
shall be constructed of two layers of diagonal
sheathing boards at 90 degrees (1.57 rad) to each other on
the same face of the supporting members. Each chord
shall be considered as a beam with uniform load per foot
equal to 50 percent of the unit shear due to diaphragm
action. The load shall be assumed as acting normal to the
chord in the plan of the diaphragm in either direction. The
span of the chord or portion thereof shall be the distance
between framing members of the diaphragm, such as the
joists, studs and blocking that serve to transfer the
assumed load to the sheathing. The shear capacity of double
diagonally sheathed diaphragms of Southern pine or
Douglas fir-larch shall not exceed 600 plf (8756 kN/m) of
width. The shear capacity shall be adjusted by reduction
factors of 0.82 for framing members of species with a specific
gravity equal to or greater than 0.42 but less than
0.49 and 0.65 for species with a specific gravity of less
than 0.42, as contained in the AF&PA NDS. Nailing of
diagonally sheathed lumber diaphragms shall be in accordance
with Table 2306.3.3.

Gypsum board diaphragm ceilings. Gypsum
board diaphragm ceilings shall be in accordance with Section
2508.5.

International Building Code 2306.3.1

Wood structural panel diaphragms. Wood
structural panel diaphragms are permitted to resist horizontal
forces using the allowable shear capacities set forth in
Table 2306.3.1 or 2306.3.2. The allowable shear capacities
are permitted to be calculated by principles of mechanics
without limitations by using values for fastener strength in
the AF&PA NDS, structural design properties for wood
structural panels based on DOC PS-1 and DOC PS-2 or
wood structural panel design properties given in the APA
Panel Design Specification (PDS).

International Building Code 2306.3.2

Shear capacities modifications. The allowable
shear capacities in Tables 2306.3.1 and 2306.3.2 for horizontal
wood structural panel diaphragms shall be increased
40 percent for wind design.

International Building Code 2306.3.3

Diagonally sheathed lumber diaphragms.
Diagonally sheathed lumber diaphragms shall be nailed in
accordance with Table 2306.3.3.

International Building Code 2306.3.4

Single diagonally sheathed lumber diaphragms.
Single diagonally sheathed lumber diaphragms
shall be constructed of minimum 1-inch (25 mm) thick
nominal sheathing boards laid at an angle of approximately
45 degrees (0.78 rad) to the supports. The shear capacity for
single diagonally sheathed lumber diaphragms of southern
pine or Douglas fir-larch shall not exceed 300 plf (4378
N/m) of width. The shear capacities shall be adjusted by
reduction factors of 0.82 for framing members of species
with a specific gravity equal to or greater than 0.42 but less
than 0.49 and 0.65 for species with a specific gravity of less
than 0.42, as contained in the AF&PA NDS.

End joints. End joints in adjacent boards
shall be separated by at least one stud or joist space and
there shall be at least two boards between joints on the
same support.

Single diagonally sheathed lumber diaphragms.
Single diagonally sheathed lumber diaphragms
made up of 2-inch (51 mm) nominal diagonal
lumber sheathing fastened with 16d nails shall be
designed with the same shear capacities as shear panels
using 1-inch (25 mm) boards fastened with 8d nails, provided
there are not splices in adjacent boards on the same
support and the supports are not less than 4 inch (102
mm) nominal depth or 3 inch (76 mm) nominal thickness.

International Building Code 2306.3.4.1

End joints. End joints in adjacent boards
shall be separated by at least one stud or joist space and
there shall be at least two boards between joints on the
same support.

International Building Code 2306.3.4.2

Single diagonally sheathed lumber diaphragms.
Single diagonally sheathed lumber diaphragms
made up of 2-inch (51 mm) nominal diagonal
lumber sheathing fastened with 16d nails shall be
designed with the same shear capacities as shear panels
using 1-inch (25 mm) boards fastened with 8d nails, provided
there are not splices in adjacent boards on the same
support and the supports are not less than 4 inch (102
mm) nominal depth or 3 inch (76 mm) nominal thickness.

International Building Code 2306.3.5

Double diagonally sheathed lumber diaphragms.
Double diagonally sheathed lumber diaphragms
shall be constructed of two layers of diagonal
sheathing boards at 90 degrees (1.57 rad) to each other on
the same face of the supporting members. Each chord
shall be considered as a beam with uniform load per foot
equal to 50 percent of the unit shear due to diaphragm
action. The load shall be assumed as acting normal to the
chord in the plan of the diaphragm in either direction. The
span of the chord or portion thereof shall be the distance
between framing members of the diaphragm, such as the
joists, studs and blocking that serve to transfer the
assumed load to the sheathing. The shear capacity of double
diagonally sheathed diaphragms of Southern pine or
Douglas fir-larch shall not exceed 600 plf (8756 kN/m) of
width. The shear capacity shall be adjusted by reduction
factors of 0.82 for framing members of species with a specific
gravity equal to or greater than 0.42 but less than
0.49 and 0.65 for species with a specific gravity of less
than 0.42, as contained in the AF&PA NDS. Nailing of
diagonally sheathed lumber diaphragms shall be in accordance
with Table 2306.3.3.

International Building Code 2306.3.6

Gypsum board diaphragm ceilings. Gypsum
board diaphragm ceilings shall be in accordance with Section
2508.5.

International Building Code 2306.4.1

Wood structural panel shear walls. The allowable
shear capacities for wood structural panel shear walls
shall be in accordance withTable 2306.4.1. These capacities
are permitted to be increased 40 percent for wind design.
Shear walls are permitted to be calculated by principles of
mechanics without limitations by using values for nail
strength given in the AF&PA NDS and wood structural
panel design properties given in the APA Panel Design
Specification.

International Building Code 2306.4.2

Lumber sheathed shear walls. Single and double
diagonally sheathed lumber diaphragms are permitted using
the construction and allowable load provisions of Sections
2306.3.4 and 2306.3.5.

International Building Code 2306.4.3

Particleboard shear walls. The design shear
capacity of particleboard shear walls shall be in accordance
with Table 2306.4.3. Shear panels shall be constructed with
particleboard sheets not less than 4 feet by 8 feet (1219 mm
by 2438 mm), except at boundaries and changes in framing.
Particleboard panels shall be designed to resist shear only,
and chords, collector members and boundary elements shall
be connected at all corners. Panel edges shall be backed with
2-inch (51 mm) nominal or wider framing. Sheets are permitted
to be installed either horizontally or vertically. For 3/8-inch
(9.5 mm) particleboard sheets installed with the long dimension
parallel to the studs spaced 24 inches (610 mm) o.c, nails
shall be spaced at 6 inches (152 mm) o.c. along intermediate
framing members. For all other conditions, nails of the same
size shall be spaced at 12 inches (305mm)o.c. along intermediate
framing members. Particleboard panels less than 12
inches (305 mm) wide shall be blocked. Particleboard shall
not be used to resist seismic forces in structures in Seismic
Design Category D, E or F.

International Building Code 2306.4.4

Fiberboard shear walls. The design shear capacity
of fiberboard shear walls shall be in accordance with
Table 2306.4.4. The fiberboard sheathing shall be applied
vertically or horizontally to wood studs not less than 2 inch
(51 mm) in nominal thickness spaced 16 inches (406 mm)
o.c. Blocking not less than 2 inch (51 mm) nominal in thickness
shall be provided at horizontal joints. Fiberboard shall
not be used to resist seismic forces in structures in Seismic
Design Category D, E or F.

International Building Code 2306.4.5

Shear walls sheathed with other materials.
Shear capacities forwalls sheathed with lath, plaster or gypsum
board shall be in accordance with Table 2306.4.5.
Shear walls sheathed with lath, plaster or gypsum board
shall be constructed in accordance with Chapter 25 and Section
2306.4.5.1. Walls resisting seismic loads shall be subject
to the limitations in Section 12.2.1 of ASCE 7.

Application of gypsum board or lath and
plaster to wood framing.

Joint staggering. End joints of adjacent
courses of gypsum board shall not occur over the
same stud.

Blocking. Where required in Table
2306.4.5, wood blocking having the same cross-sectional
dimensions as the studs shall be provided at
joints that are perpendicular to the studs.

Fastening. Studs, top and bottom plates
and blocking shall be fastened in accordance with
Table 2304.9.1.

Fasteners. The size and spacing of fasteners
shall be set forth in Table 2306.4.5. Fasteners
shall be spaced not less than 3/8 inch (9.5 mm) from
edges and ends of gypsum boards or sides of studs,
blocking and top and bottom plates.

Gypsum lath. Gypsum lath shall be
applied perpendicular to the studs. Maximum allowable
shear values shall be as set forth in Table
2306.4.5.

Gypsum sheathing. Four-foot-wide
(1219 mm) pieces of gypsum sheathing shall be
applied parallel or perpendicular to studs.
Two-foot-wide (610 mm)pieces of gypsum sheathing
shall be applied perpendicular to the studs. Maximum
allowable shear values shall be as set forth in Table
2306.4.5.

Other gypsum boards. Gypsum board
shall be applied parallel or perpendicular to studs.
Maximum allowable shear values shall be as set forth
in Table 2306.4.5.

International Building Code 2306.4.5.1

Application of gypsum board or lath and
plaster to wood framing.

Joint staggering. End joints of adjacent
courses of gypsum board shall not occur over the
same stud.

Blocking. Where required in Table
2306.4.5, wood blocking having the same cross-sectional
dimensions as the studs shall be provided at
joints that are perpendicular to the studs.

Fastening. Studs, top and bottom plates
and blocking shall be fastened in accordance with
Table 2304.9.1.

Fasteners. The size and spacing of fasteners
shall be set forth in Table 2306.4.5. Fasteners
shall be spaced not less than 3/8 inch (9.5 mm) from
edges and ends of gypsum boards or sides of studs,
blocking and top and bottom plates.

Gypsum lath. Gypsum lath shall be
applied perpendicular to the studs. Maximum allowable
shear values shall be as set forth in Table
2306.4.5.

Gypsum sheathing. Four-foot-wide
(1219 mm) pieces of gypsum sheathing shall be
applied parallel or perpendicular to studs.
Two-foot-wide (610 mm)pieces of gypsum sheathing
shall be applied perpendicular to the studs. Maximum
allowable shear values shall be as set forth in Table
2306.4.5.

Other gypsum boards. Gypsum board
shall be applied parallel or perpendicular to studs.
Maximum allowable shear values shall be as set forth
in Table 2306.4.5.

International Building Code 2306.4.5.1.1

Joint staggering. End joints of adjacent
courses of gypsum board shall not occur over the
same stud.

International Building Code 2306.4.5.1.2

Blocking. Where required in Table
2306.4.5, wood blocking having the same cross-sectional
dimensions as the studs shall be provided at
joints that are perpendicular to the studs.

International Building Code 2306.4.5.1.3

Fastening. Studs, top and bottom plates
and blocking shall be fastened in accordance with
Table 2304.9.1.

International Building Code 2306.4.5.1.4

Fasteners. The size and spacing of fasteners
shall be set forth in Table 2306.4.5. Fasteners
shall be spaced not less than 3/8 inch (9.5 mm) from
edges and ends of gypsum boards or sides of studs,
blocking and top and bottom plates.

International Building Code 2306.4.5.1.5

Gypsum lath. Gypsum lath shall be
applied perpendicular to the studs. Maximum allowable
shear values shall be as set forth in Table
2306.4.5.

International Building Code 2306.4.5.1.6

Gypsum sheathing. Four-foot-wide
(1219 mm) pieces of gypsum sheathing shall be
applied parallel or perpendicular to studs.
Two-foot-wide (610 mm)pieces of gypsum sheathing
shall be applied perpendicular to the studs. Maximum
allowable shear values shall be as set forth in Table
2306.4.5.

International Building Code 2306.4.5.1.7

Other gypsum boards. Gypsum board
shall be applied parallel or perpendicular to studs.
Maximum allowable shear values shall be as set forth
in Table 2306.4.5.