International Building Code Section 2303 – International Building Code 2006 Discussions

International Building Code 2303.1

General. Structural sawn lumber; end-jointed lumber;
prefabricatedwood I-joists; structural glued-laminated timber;
wood structural panels, fiberboard sheathing (when used structurally);
hardboard siding (when used structurally);
particleboard; preservative-treated wood; structural log members;
structural composite lumber; round timber poles and
piles; fire-retardant-treated wood; hardwood plywood; wood
trusses; joist hangers; nails; and staples shall conform to the
applicable provisions of this section.

Sawn lumber. Sawn lumber used for load-supporting
purposes, including end-jointed or edge-glued lumber,
machine stress-rated or machine-evaluated lumber,
shall be identified by the grade mark of a lumber grading or
inspection agency that has been approved by an accreditation
body that complies with DOC PS 20 or equivalent.
Grading practices and identification shall comply with rules
published by an agency approved in accordance with the
procedures of DOC PS 20 or equivalent procedures. 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 is permitted
to be accepted for precut, remanufactured or
rough-sawn lumber and for sizes larger than 3 inches (76
mm) nominal thickness.
Approved end-jointed lumber is permitted to be used
interchangeably with solid-sawn members of the same species
and grade.

Prefabricated wood I-joists. Structural capacities
and design provisions for prefabricated wood I-joists
shall be established and monitored in accordance with
ASTM D 5055.

Structural glued-laminated timber. Glued-laminated
timbers shall be manufactured and identified as
required in AITC A190.1 and ASTM D 3737.

Wood structural panels.Wood structural panels,
when used structurally (including those used for siding, roof
and wall sheathing, subflooring, diaphragms and built-up
members), shall conform to the requirements for their type
in DOC PS 1 or PS 2. Each panel or member shall be identified
for grade and glue type by the trademarks of an
approved testing and grading agency.Wood structural panel
components shall be designed and fabricated in accordance
with the applicable standards listed in Section 2306.1 and
422 2006 INTERNATIONAL BUILDING CODE
WOOD
?
identified by the trademarks of an approved testing and
inspection agency indicating conformance with the applicable
standard. In addition, wood structural panels when permanently
exposed in outdoor applications shall be of
exterior type, except that wood structural panel roof sheathing
exposed to the outdoors on the underside is permitted to
be interior type bonded with exterior glue, Exposure 1.

Fiberboard. Fiberboard for its various uses shall
conform to ASTM C 208. Fiberboard sheathing, when used
structurally, shall be identified by an approved agency as
conforming to ASTM C 208.

Jointing. To ensure tight-fitting assemblies,
edges shall be manufactured with square, shiplapped,
beveled, tongue-and-groove or U-shaped joints.

Roof insulation. Where used as roof insulation
in all types of construction, fiberboard shall be protected
with an approved roof covering.

Wall insulation. Where installed and
fireblocked to comply with Chapter 7, fiberboards are
permitted as wall insulation in all types of construction.
In fire walls and fire barriers, unless treated to comply
with Section 803.1 for ClassAmaterials, the boards shall
be cemented directly to the concrete, masonry or other
noncombustible base and shall be protected with an
approved noncombustible veneer anchored to the base
without intervening airspaces.

Protection. Fiberboard wall insulation
applied on the exterior of foundation walls shall be
protected below ground level with a bituminous coating.

Hardboard. Hardboard siding used structurally
shall be identified by an approved agency conforming to
AHA A135.6. Hardboard underlayment shall meet the
strength requirements of 7/32-inch (5.6 mm) or 1/4-inch (6.4
mm)service class hardboard planed or sanded on one side to
a uniform thickness of not less than 0.200 inch (5.1 mm).
Prefinished hardboard paneling shall meet the requirements
of AHA A135.5. Other basic hardboard products shall meet
the requirements ofAHAA135.4. Hardboard products shall
be installed in accordance with manufacturer’s recommendations.

Particleboard. Particleboard shall conform to
ANSI A208.1. Particleboard shall be identified by the grade
mark or certificate of inspection issued by an approved
agency. Particleboard shall not be utilized for applications
other than indicated in this section unless the particleboard
complies with the provisions of Section 2306.4.3.

Floor underlayment. Particleboard floor
underlayment shall conform to Type PBU of ANSI
A208.1. Type PBU underlayment shall not be less than
1/4-inch (6.4 mm) thick and shall be installed in accordance
with the instructions of the Composite Panel Association.

Preservative-treated wood. Lumber, timber, plywood,
piles and poles supporting permanent structures
required by Section 2304.11 to be preservative treated shall
conform to the requirements of the applicable AWPA Standard
U1 and M4 for the species, product, preservative and
end use. Preservatives shall be listed in Section 4 of AWPA
U1. Lumber and plywood used in wood foundation systems
shall conform to Chapter 18.

Identification. Wood required by Section
2304.11 to be preservative treated shall bear the quality
mark of an inspection agency that maintains continuing
supervision, testing and inspection over the quality of the
preservative-treated wood. Inspection agencies for preservative-
treated wood shall be listed by an accreditation
body that complies with the requirements of the American
Lumber Standards TreatedWood Program, or equivalent.
The quality mark shall be on a stamp or label
affixed to the preservative-treated wood, and shall
include the following information:
1. Identification of treating manufacturer.
2. Type of preservative used.
3. Minimum preservative retention (pcf).
4. End use for which the product is treated.
5. AWPAstandard to which the product was treated.
6. Identity of the accredited inspection agency.

Moisture content. Where preservative-
treated wood is used in enclosed locations where
drying in service cannot readily occur, such wood shall
be at a moisture content of 19 percent or less before being
covered with insulation, interior wall finish, floor covering
or other materials.

Structural composite lumber. Structural capacities
for structural composite lumber shall be established and
monitored in accordance with ASTM D 5456.

Structural log members. Stress grading of
structural log members of nonrectangular shape, as typically
used in log buildings, shall be in accordance with
ASTMD3957. 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.

Round timber poles and piles. Round timber
poles and piles shall comply withASTMD3200 andASTM
D 25, respectively

International Building Code 2303.1.1

International Building Code 2303.1.10

International Building Code 2303.1.11

Round timber poles and piles. Round timber
poles and piles shall comply withASTMD3200 andASTM
D 25, respectively

International Building Code 2303.1.2

Prefabricated wood I-joists. Structural capacities
and design provisions for prefabricated wood I-joists
shall be established and monitored in accordance with
ASTM D 5055.

International Building Code 2303.1.3

Structural glued-laminated timber. Glued-laminated
timbers shall be manufactured and identified as
required in AITC A190.1 and ASTM D 3737.

International Building Code 2303.1.4

International Building Code 2303.1.5

Fiberboard. Fiberboard for its various uses shall
conform to ASTM C 208. Fiberboard sheathing, when used
structurally, shall be identified by an approved agency as
conforming to ASTM C 208.

Jointing. To ensure tight-fitting assemblies,
edges shall be manufactured with square, shiplapped,
beveled, tongue-and-groove or U-shaped joints.

Roof insulation. Where used as roof insulation
in all types of construction, fiberboard shall be protected
with an approved roof covering.

Protection. Fiberboard wall insulation
applied on the exterior of foundation walls shall be
protected below ground level with a bituminous coating.

International Building Code 2303.1.5.1

Jointing. To ensure tight-fitting assemblies,
edges shall be manufactured with square, shiplapped,
beveled, tongue-and-groove or U-shaped joints.

International Building Code 2303.1.5.2

Roof insulation. Where used as roof insulation
in all types of construction, fiberboard shall be protected
with an approved roof covering.

International Building Code 2303.1.5.3

Protection. Fiberboard wall insulation
applied on the exterior of foundation walls shall be
protected below ground level with a bituminous coating.

International Building Code 2303.1.5.3.1

Protection. Fiberboard wall insulation
applied on the exterior of foundation walls shall be
protected below ground level with a bituminous coating.

International Building Code 2303.1.6

International Building Code 2303.1.7

International Building Code 2303.1.7.1

International Building Code 2303.1.8

International Building Code 2303.1.8.1

International Building Code 2303.1.8.2

International Building Code 2303.1.9

Structural composite lumber. Structural capacities
for structural composite lumber shall be established and
monitored in accordance with ASTM D 5456.

International Building Code 2303.2

Fire-retardant-treated wood. Fire-retardant-treated
wood 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, a listed flame spread index of 25 or less and show 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 centerline of the burners at any time during the test.
2006 INTERNATIONAL BUILDING CODE 423
WOOD
?

Labeling. Fire-retardant-treated lumber andwood
structural panels shall be labeled. The label shall contain the
following items:
1. The identification mark of an approved agency in
accordance with Section 1703.5.
2. Identification of the treating manufacturer.
3. The name of the fire-retardant treatment.
4. The species of wood treated.
5. Flame spread and smoke-developed index.
6. Method of drying after treatment.
7. Conformance with appropriate standards in accordance
with Sections 2303.2.2 through 2303.2.5.
8. For fire-retardant-treated wood exposed to weather,
damp or wet locations, include the words “No
increase in the listed classification when subjected to
the Standard Rain Test” (ASTM D 2898).

Strength adjustments. Design values for
untreated lumber and wood structural panels, as specified
in Section 2303.1, shall be adjusted for fire-retardant-
treated wood. Adjustments to design values shall be
based on an approved method of investigation that 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.

Wood structural panels. 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 its treatment.

Lumber. For each species of wood that is
treated, the effects of the treatment, 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 80F (27C) and for roof framing.
The roof framing modification factors shall take into
consideration the climatological location.

Exposure to weather, damp or wet locations.
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 2303.2 when subjected
to ASTM D 2898.

Interior applications. Interior fire-retardant-
treated wood shall have 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 2303.2.2.1 or 2303.2.2.2. Interior fire-retardant-
treated wood designated as Type A shall be tested in
accordance with the provisions of this section.

Moisture content. Fire-retardant-treated wood
shall be dried to amoisture 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 2303.2.2.1 for plywood and
2303.2.2.2 for lumber.

Type I and II construction applications. See
Section 603.1 for limitations on the use of fire-retardant-
treatedwood in buildings of Type I or II construction.

International Building Code 2303.2.1

International Building Code 2303.2.2

International Building Code 2303.2.2.1

International Building Code 2303.2.2.2

International Building Code 2303.2.3

International Building Code 2303.2.4

International Building Code 2303.2.5

International Building Code 2303.2.6

Type I and II construction applications. See
Section 603.1 for limitations on the use of fire-retardant-
treatedwood in buildings of Type I or II construction.

International Building Code 2303.3

Hardwood and plywood. Hardwood and decorative
plywood shall be manufactured and identified as required in
HPVA HP-1.

International Building Code 2303.4

Trusses.

Design. Wood trusses shall be designed in accordance
with the provisions of this code and accepted engineering
practice. Members are permitted to be joined by
nails, glue, bolts, timber connectors, metal connector plates
or other approved framing devices.

Truss designer. The individual or organization
responsible for the design of trusses.

Truss design drawings. The written, graphic
and pictorial depiction of each individual truss shall be
provided to the building official and approved prior to
installation. Truss design drawings shall also be provided
with the shipment of trusses delivered to the job
site. Truss design drawings shall include, at a minimum,
the information specified below:
1. Slope or depth, span and spacing;
2. Location of joints;
3. Required bearing widths;
4. Design loads as applicable;
5. Top chord live load (including snow loads);
6. Top chord dead load;
7. Bottom chord live load;
8. Bottom chord dead load;
9. Concentrated loads and their points of application
as applicable;
10. Controlling wind and earthquake loads as
applicable;
11. Adjustments to lumber and metal connector plate
design value for conditions of use;
424 2006 INTERNATIONAL BUILDING CODE
WOOD
12. Each reaction force and direction;
13. Metal connector plate type, size, thickness or
gage, and the dimensioned location of each metal
connector plate except where symmetrically
located relative to the joint interface;
14. Lumber size, species and grade for each member;
15. Connection requirements for:
15.1. Truss to truss;
15.2. Truss ply to ply; and
15.3. Field splices.
16. Calculated deflection ratio and maximum vertical
and horizontal deflection for live and total
load as applicable;
17. Maximum axial tensile and compression forces
in the truss members; and
18. Required permanent individual truss member
bracing and method per Section 2303.4.1.5,
unless a specific truss member permanent bracing
plan for the roof or floor structural system is
provided by a registered design professional.
Where required by one of the following, each individual
truss design drawing shall bear the seal and signature
of the truss designer:
1. Registered design professional; or
2. Building official; or
3. Statutes of the jurisdiction in which the project is
to be constructed.
Exceptions:
1. When a cover sheet/truss index sheet combined
into a single cover sheet is attached to the set of
truss design drawings for the project, the single
sheet/truss index sheet is the only document
that needs to be signed and sealed within the
truss submittal package.
2. When a cover sheet and a truss index sheet are
separately provided and attached to the set of
truss design drawings for the project, both the
cover sheet and the truss index sheet are the
only documents that need to be signed and
sealed within the truss submittal package.

Truss placement diagram. The truss manufacturer
shall provide a truss placement diagram that
identifies the proposed location for each individually
designated truss and references the corresponding truss
design drawing. The truss placement diagram shall be
provided as part of the truss submittal package, and with
the shipment of trusses delivered to the job site. Truss
placement diagrams shall not be required to bear the seal
or signature of the truss designer.
Exception: When the truss placement diagram is prepared
under the direct supervision of a registered
design professional, it is required to be signed and
sealed.

Truss submittal package. The truss
submittal package shall consist of each individual truss
design drawing, the truss placement diagram for the project,
the truss member permanent bracing specification
and, as applicable, the cover sheet/truss index sheet.

Truss member permanent bracing. Where
permanent bracing of truss members is required on the
truss design drawings, it shall be accomplished by one of
the following methods:
1. The trusses shall be designed so that the buckling
of any individual truss member can be resisted
internally by the structure (e.g. buckling member
T-bracing, L-bracing, etc.) of the individual truss.
The truss individual member buckling reinforcement
shall be installed as shown on the truss design
drawing or on supplemental truss member buckling
reinforcement diagrams provided by the truss
designer.
2. Permanent bracing shall be installed using standard
industry bracing details that conform with
generally accepted engineering practice. Individual
truss member continuous lateral bracing location(
s) shall be shown on the truss design drawing.

Anchorage. All transfer of loads and anchorage
of each truss to the supporting structure is the responsibility
of the registered design professional.

Alterations to trusses. Truss members and
components shall not be cut, notched, drilled, spliced or
otherwise altered in any way without written concurrence
and approval of a registered design professional.
Alterations resulting in the addition of loads to any member
(e.g., HVAC equipment, water heater) shall not be
permitted without verification that the truss is capable of
supporting such additional loading.

Metal-plate-connected trusses. In addition to
Sections 2303.4.1 through 2303.4.1.7, the design, manufacture
and quality assurance of metal-plate-connected wood
trusses shall be in accordance with TPI 1. Manufactured
trusses shall comply with Section 1704.6 as applicable.

International Building Code 2303.4.1

Truss designer. The individual or organization
responsible for the design of trusses.

Anchorage. All transfer of loads and anchorage
of each truss to the supporting structure is the responsibility
of the registered design professional.

International Building Code 2303.4.1.1

Truss designer. The individual or organization
responsible for the design of trusses.

International Building Code 2303.4.1.2

International Building Code 2303.4.1.3

International Building Code 2303.4.1.4

International Building Code 2303.4.1.5

International Building Code 2303.4.1.6

Anchorage. All transfer of loads and anchorage
of each truss to the supporting structure is the responsibility
of the registered design professional.

International Building Code 2303.4.1.7

International Building Code 2303.4.2

International Building Code 2303.5

Test standard for joist hangers and connectors. For
the required test standards for joist hangers and connectors, see
Section 1715.1.

International Building Code 2303.6

Nails and staples. Nails and staples shall conform to
requirements of ASTM F 1667. Nails used for framing and
sheathing connections shall have minimum average bending
yield strengths as follows: 80 kips per square inch (ksi) (551
MPa) for shank diameters larger than 0.177 inch (4.50 mm) but
not larger than 0.254 inch (6.45 mm), 90 ksi (620 MPa) for
shank diameters larger than 0.142 inch (3.61 mm) but not
larger than 0.177 inch (4.50 mm) and 100 ksi (689 MPa) for
shank diameters of at least 0.099 inch (2.51 mm) but not larger
than 0.142 inch (3.61 mm).
2006 INTERNATIONAL BUILDING CODE 425
WOOD

International Building Code 2303.7

Shrinkage. Consideration shall be given in design to
the possible effect of cross-grain dimensional changes considered
vertically which may occur in lumber fabricated in a green
condition.