Deletion legend:
[1- Default – Not related to structural wind resistance design]
[2- Fire/Life Safety]
[3- Covered in model base code]
[4- Code Cycle Modification to be submitted to strike section and
refer to appropriate FBC,B sections]
SECTION
R4409
[4- Code Cycle Modification to be submitted to strike section and
refer to appropriate FBC,B sections]
HIGH-VELOCITY
HURRICANE ZONES—WOOD
R4409.1
General.
R4409.1.1
Design. Wood members
and their fastenings shall be designed to comply with this code by methods
based on rational analysis or approved laboratory testing procedures, both
performed in accordance with fundamental principles of theoretical and applied
mechanics.
R4409.1.2
Workmanship. Wood
members shall be framed, anchored, tied and braced to develop the strength and
rigidity necessary for the purposes for which they are used and to resist the
loads imposed as set forth in this code. Wood construction shall be in
conformance with the tolerances, quality and methods of construction as prescribed
by the standards in Chapter 43 of this code.
R4409.1.3
Fabrication.
R4409.1.3.1 Preparation, fabrication and
installation of wood members and the glues, connectors and mechanical devices
for fastening shall conform to good engineering practice.
R4409.1.3.2 Any person desiring to manufacture or
fabricate wood truss assemblies shall obtain a certificate of competency from
the authority having jurisdiction.
R4409.1.4 The following standards, as set forth
in Chapter 43 of this code, are hereby adopted for the design and quality of
wood members and their fastenings:
R4409.1.4.1 American Hardboard Products
Association
887-B Wilmette Road,
Palatine, IL 60067 AHA
1. Basic Hardboard ANSI/AHA A135.4-1982
2. Prefinished Hardboard Paneling ANSI/AHA
A135.5-1982
3. Hardboard Siding ANSI/AHA A135.6-1990
4. Cellulosic Fiberboard ANSI/AHA
A194.1-1985
5. Recommended Product and Application
Specification - Structural Insulating Roof Deck, I.B. Spec. No. 1
6. Recommended Product and Application
Specification - 1/2 inch Fiberboard Nail-Base- Sheathing I.B. Spec. No. 2
7. Recommended Product and Application
Specification - 1/2 inch Intermediate Fiberboard Sheathing I.B. Spec. No. 3
R4409.1.4.2 American Institute of Timber
Construction
333 West Hampden Avenue,
Englewood, CO80110 AITC
1. Typical
Construction Details AITC 104
2. Code
of Suggested Practices AITC 106
3. Standard
for Heavy Timber Construction AITC 108
4. Standard
for Preservative Treatment for Structural Glued Laminated Timber AITC 109
5. Standard
Appearance Grades for Structural Glued Laminated Timber AITC 110
6. Standard
for Tongue and Groove Heavy Timber Roof Decking AITC 112
7. Standard
for Dimensions of Glued Laminated Structural Members AITC 113
8. Standard
Specifications for Structural Glued Laminated Timber of Softwood Species AITC
117
9. Standard
Specifications for Hardwood Glued Laminated Timber AITC 119
10. Technical Report No. 7, Calculation of
Fire Resistance of Glued Laminated Timber
11. Structural Glued Laminated Timber
ANSI/AITC A190.1
TABLE
R4408.11
CHAIN
LINK FENCE MINIMUM REQUIREMENTS
Fence Height (ft) Terminal Post Line
Post Terminal Post Concrete Line Post Concrete
Dimensions Dimensions Foundation
Size Foundation Size
(in inches) (in
inches) (diameter × depth) (diameter ×
depth)
(o.d. × wall
thickness) (o.d. × wall thickness) (in inches) (in inches)
Up to 4 23/8
× 0.042 15/8 × 0.047 10 ×
24 8 × 24
Over 4 to 5 23/8 × 0.042 17/8 × 0.055 10 × 24 8 × 24
Over 5 to 6 23/8 × 0.042 17/8 × 0.065 10 × 24 8 × 24
Over 6 to 8 23/8 × 0.110 23/8 × 0.095 10 × 36 10 × 36
Over 8 to 10 27/8 × 0.110 23/8 × 0.130 12 × 40 10 × 40
Over 10 to 12 27/8 × 0.160 27/8 × 0.120 12 × 42 12 × 42
For SI: 1 inch = 25.4 mm.
Notes:
1. This Table is applicable only to fences with
unrestricted airflow.
2. Fabric: 121/2 gauge minimum.
3. Tension Bands: Use one less than the height
of the fence in feet evenly spaced.
4. Fabric Ties: Must be minimum the same gauge
of the fabric.
5. Fabric Tie Spacing on the Top Rail: Five
ties between posts, evenly spaced.
6. Fabric Tie Spacing on Line Posts: One less
than height of the fence in feet, evenly spaced.
7. Either top rail or top tension wire shall be
used.
8. Braces must be used at Terminal Posts if top
tension wire is used instead of Top Rail.
9. Post Spacing: 10 foot (3 m) on center
maximum.
10. Posts shall be
embedded to within 6 inch (152 mm) from the bottom of the foundation.
11. In order to follow the
contour of the land, the bottom of the fence may clear the contour of the
ground by up to 5 inch (127 mm) without increasing table values to the next
higher limit.
R4409.1.4.3 APA The Engineered Wood Association
(Formerly APA American Plywood Association) P.O. Box 11700, Tacoma, WA 98411
1. APA
Design Construction Guide, Residential and Commercial E30D
2. Plywood
Design Specification Y510J
3. Plywood
Design Specification-Design and Fabrication of Plywood Beams Supplement No. 1
S811
4. Plywood
Design Specification-Design and Fabrication of Plywood Beams Supplement No. 2
S812
5. Plywood
Design Specification-Design and Fabrication of Plywood Stressed-Skin Panels
Supplement No. 3 U813
6. Plywood
Design Specifications-Design and Fabrication of Plywood Sandwich Panels
Supplement No. 4 U814
7. Plywood
Design Specifications-Design and Fabrication of All-Plywood Beams. Supplement
No. 5 H815
8. Plywood
Folded Plate, Laboratory Report 21 V910
9. APA
Design/Construction Guide Diaphragms L350
10. Performance Standards and Policies for
Structural-Use Panels PRP-108
11. 303 Siding Manufacturing Specifications
B840
R4409.1.4.4 American Society for Testing
Materials
1916 Race Street,
Philadelphia, PA 19103-1187 ASTM
1. Standard Test Methods for Mechanical
Fasteners in Wood D 1761
2. Accelerated Weathering on
Fire-Retardant Treated Wood for Fire Testing D 2898
3. Surface Burning Characteristics of
Building Materials E 84
4. Hygroscopic Properties of
Fire-Retardant Wood and Wood-Base Products D 3201
5. Standard Specifications for Adhesives
for Field-Gluing Plywood to Lumber Framing for Floor Systems D 3498
R4409.1.4.5 American Wood Preservers Association
P.O. Box 361784,
Birmingham, AL 35236-1784
1. AWPA Use Category Systems Standard U1
2. AWPA Standard M4 Care of Pressure
Treated Wood Products
R4409.1.4.6 National Institute for Standards and
Technology Standard Development Services Section, Standards Application and
Analysis Division, Washington, D.C. 20234 NIST
1. Mat-Formed Particleboard CS236
2. Structural Glued Laminated Timber PS56
3. Construction and Industrial Plywood PS1
4. American Softwood Lumber Standard PS20
5. Performance Standard for Wood Based
Structural Use Panels PS2*
*All wood-based structural
panels except plywood shall have Product Approval and shall be tested in
accordance with High-Velocity Hurricane Zone testing protocols.
R4409.1.4.7 American Forest and
Paper Association 1111 19 Street NW, Washington, D.C. 20036
1.
ANSI/AF&PA National Design Specification for Wood Construction, 2001 2005
2.
ANSI/AF&PA Design Values for Wood Construction, 2001 2005
3. Wood
Structural Design Data, 1992
4. Span
Tables for Joists and Rafters, 2005
5. Design
Values for Joists and Rafters, 2005
6. Wood
Construction Data No. 1, Details for Conventional Wood Frame Construction, 2001
7. Wood
Construction Data No. 4, Plank-and-Beam Framing for Residential Building, 2003
8. Wood
Construction Data No. 5, Heavy Timber Construction Details, 2004
9. Wood Construction
Data No. 6, Design of Wood Frame Structures for Permanence, 2006
10.
ANSI/AF&PA PWF-2007 Permanent Wood Foundation (PWF) Design Specification,
2007
11.
ANSI/AF&PA WFCM-2001, Wood Frame Construction Manual for one and Two-Family
Dwellings, 2001
R4409.1.4.8 Timber Company, Inc.
2402 Daniels Street,
Madison, WI 53704 TECO
Performance Standards
and Policies for Structural use Panels. PRP-133
R4409.1.4.9 Truss Plate Institute
218 N. Lee Street, Suite
312, Alexandria, VA 22314
1. National Design Standard for Metal
Plate Connected Wood Truss Construction (Excluding Chapter 2).
2. Building Component Safety Information
(BCSI 1-03) Guide to Good Practice for Handling, Installing & Bracing of
Metal Plate Connected Wood Trusses [A joint publication with the Wood Truss
Council of America (WTCA)].
R4409.1.4.10
Underwriters Laboratories, Inc.
333 Pfingsten Road,
Northbrook, IL 60062
Test Methods for Fire
Resistance of UL-790 Roof Covering Materials
[2- Fire/Life Safety]
SECTION
R4409.2
HIGH-VELOCITY
HURRICANE ZONES—QUALITY
R4409.2.1
Identification. All
lumber used structurally, including end-jointed lumber, shall be identified by
the grade mark of a lumber grading or inspection bureau or agency approved by
the Board of Review of the American Lumber Standards Committee or the Canadian
Lumber Standards Administrative Board: except that precut material, rough-sawn
lumber and lumber thicker than 2 inches (51 mm) may be covered by a certificate
of inspection in lieu of grade marking. The glued joints in end-jointed lumber,
when used for load supporting purposes, shall be certified to be in accordance
with the appropriate grading rules.
R4409.2.1.1 Structural glued laminated timber
shall be manufactured and identified as required in ANSI/AITC 190.1 as adopted
in Section R4409.1.4.
R4409.2.1.2 All wood-based structural panels used
structurally, including siding, roof sheathing, wall sheathing, floor
sheathing, diaphragms and built-up members, shall be identified for grade and
exposure level by the grade stamp of an approved testing and grading agency
indicating conformance with PS-1, PS-2, APA PRP-108 or TECO PRP-133 as adopted
in Section R4409.1.4.
R4409.2.1.3 Wood shingles and/or shakes shall be
identified by the grademark
grade mark of
an approved grading or inspection bureau or agency.
R4409.2.1.4 Fiberboard for its various uses shall
conform to ANSI/AHA A 194.1.
R4409.2.1.5 Hardboard shall conform to AHA
standards as adopted in Section R4409.1.4, and shall be identified as to
classification.
R4409.2.1.6 Particleboard shall conform to the
mat-formed particleboard standard, NIST CS236, as adopted in Section
R4409.1.4.6, and shall be identified by the grade mark or certificate of
inspection issued by an approved agency.
R4409.2.1.7 All
lumber and wood-based structural panels required to be fire-retardant-treated
shall bear permanent identification showing the fire performance rating thereof
issued by an approved testing agency having a follow-up service. When exposed
to the weather the material shall be permanently identified as suitable for
such use in accordance with Section R4409.14.4. When exposed to sustained high
humidity, the material shall be permanently identified as a low hygroscopic
type suitable for interior use. Allowable design values, including connection
design values, for lumber, glued laminated timber and wood-based structural
panels, pressure treated with fire retardant chemicals shall be obtained from
the company providing the treatment and redrying services. Listing of allowable
design values shall be submitted and product approved.
[2- Fire/Life
Safety]
R4409.2.1.8 All lumber, sawn timber, wood-based
structural panels and poles supporting permanent structures and required by
this code to be pressure treated and as described in the AWPA standards shall
bear the quality mark of an approved inspection agency which maintains
continued supervision, testing and inspection over the product. Agencies shall
be accredited in accordance with the procedures of the American Lumber Standard
(PS 20) or approved equivalent.
R4409.2.1.9 Pressure-treated poles shall be
treated in accordance with AWPA U1 for sawn timber posts (Commodity
Specification A, Use Category 4B) and for round timber posts (Commodity
Specification B, Use Category 4B).
R4409.2.1.10 The quality mark shall contain, as a
minimum, the following information:
1. The treating company and plant location
2. The AWPA standard to which the product
is treated
3. The trademark of an approved inspection
agency which maintains continued supervision, testing and inspection over the
quality of the product as described in the AWPA standards
4. The preservative used
5. The amount of retention of the chemical
per cubic foot of wood
6. If applicable, the method of drying
after treatment
7. The purpose for which the wood has been
treated: ground contact, above ground or foundation
Exception: When the size of individual pieces,
e.g. lumber less than 1 inch (25 mm) in nominal thickness, or lumber less than
nominal 1x5 or 2x4, or lumber 36 inches (914 mm) and shorter, except that 5/4x4
shall be quality marked, prevents application of full legible marks, the
quality mark shall be applied by stamping the faces of exterior pieces or by
end labeling not less than 25 percent of the pieces of a bundled unit.
R4409.2.1.11 All wood-based structural panels,
including those made of fiberboard, hardboard and particleboard shall have
Product Approval. Product Approval shall be given upon certification by an
approved independent testing laboratory that the product:
1. Complies with the applicable standards
set forth above
2. The product complies with the
manufacturer's published design properties before and after a wet-dry cycle
3. The product when tested dry maintains a
safety factor of 2:1 and when tested after the cycles specified in Section
R4409.2.1.11(2) above maintains a safety factor of 1.5:1. Testing shall be as
specified in the testing protocol.
R4409.2.2 Wood-based structural panels
permanently exposed in outdoor locations shall be rated for exterior use. When
used for roof sheathing exposed to the outdoors on the underside or used
structurally for wall, floor or roof cladding or for diaphragms, the panels
shall be rated for Exposure 1 or exterior use.
R4409.2.3 All lumber 2 inches (51 mm) or less
in thickness shall contain not more than 19 percent moisture at the time of
permanent incorporation in a building or structure and/or at the time of
treatment with a wood preservative.
R4409.2.4
Grade and species.
R4409.2.4.1 All structural wood members not
limited by other sections of this section shall be of sufficient size and
capacity to carry all loads as required by Section R4403 without exceeding the
allowable design stresses specified in the National Design Specification for
Wood Construction and in compliance with Section R4409.4.
R4409.2.4.2 Lumber boards used for floor and roof
sheathing shall be in accordance with Table R4409.2.4.2.
TABLE
R4409.2.4.2
MINIMUM
GRADE REQUIREMENTS: BOARD GRADES
FLOOR OR ROOF SHEATHING GRADING RULES
Utility NLGA, WCLIB or WWPA
No. 4 Common or Utility NLGA, WCLIB, WWPA, NHPMA or NELMA
No. 3 SPIB
Merchantable RIS
SECTION
R4409.3
Reserved
SECTION
R4409.4
HIGH-VELOCITY
HURRICANE ZONES—
UNIT
STRESSES
R4409.4.1
General.
R4409.4.1.1 Lumber used for joists, rafters,
trusses, columns, beams and/or other structural members shall be of no less
strength than No. 2 grade of Southern Pine, Douglas Fir-Larch, Hem-Fir or
Spruce-Pine-Fir. Joists and rafters shall be sized according to AF&PA Span
Tables for Joists and Rafters adopted in Section R4409.1.4.
R4409.4.1.2 Lumber used for studs in exterior
walls and interior bearing walls shall be of no less strength than Stud Grade
of Southern Pine, Douglas Fir-Larch, Hem-Fir or Spruce-Pine-Fir and capable of
resisting all loads determined in accordance with Section R4403. The unbraced
height of the wall shall be no more than 8 feet 6 inches (2.6 m) (including top
and bottom plates). Heights may be increased where justified by rational
analysis prepared by a registered professional engineer or registered architect
proficient in structural design.
R4409.4.1.3 Lumber
used for studs in interior non-bearing walls shall have a modulus of elasticity
of no less than 0.9 by 106 psi (6205 MPa).
[1- Default – Not
related to structural wind resistance design]
R4409.4.1.4 The designer shall specify on the
design drawings the size, spacing, species and grade of all load supporting
members.
R4409.4.2 Allowable stress design value may be
modified for repetitive, duration, etc., factors where design is by a
registered professional engineer or registered architect proficient in
structural design or where such modified values are reflected in the tables of
the standards in Section R4409.1.4.
SECTION
R4409.5
HIGH-VELOCITY
HURRICANE ZONES—
VERTICAL
FRAMING
R4409.5.1
Studs in bearing and exterior walls.
Studs in walls framing over 8 feet 6 inches (2.6 m) (including top and bottom
plates) or supporting floor and roof loads shall be designed by rational
analysis prepared by a registered professional engineer or registered architect
proficient in structural design.
R4409.5.1.1
Minimum size. Studs
shall be not less than 2x6 for exterior walls or 2x4 for interior bearing or
load resisting walls unless designed by rational analysis by a registered
licensed engineer or registered architect proficient in structural design.
R4409.5.1.2
Spacing. Studs shall
be spaced not more than 16 inches (406 mm) on center unless designed by
rational analysis as a system of columns and beams by a registered licensed
engineer or registered architect proficient in structural design.
R4409.5.1.3
Placing.
R4409.5.1.3.1 Studs in exterior and bearing walls
shall be placed with the longer dimension perpendicular to the wall.
R4409.5.1.3.2 Studs in exterior walls and in
bearing walls shall be supported by foundation plates, sills, or girders or
floor framing directly over supporting walls or girders. Stud bearing walls
when perpendicular to supporting joists may be offset from supporting walls or
girders not more than the depth of the joists unless such joists are designed
for the extra loading conditions.
R4409.5.1.3.3 Stud walls framing into base plates
of exterior walls and interior bearing walls resting on masonry or concrete
shall be anchored past the plate to the masonry or concrete, or shall be
anchored to a sill plate which is anchored in accordance with Section
R4409.5.1.4.1 when the net wind uplift is up to 300 pounds per foot (4378 N/m).
R4409.5.1.4
Sills and/or base plates.
R4409.5.1.4.1 Sills and/or base plates, where
provided in contact with masonry or concrete, shall be of an approved durable
species or be treated with an approved preservative and shall be attached to
the masonry or concrete with 1/2 inch (13 mm) diameter bolts with oversized
washer spaced not over 2 feet (610 mm) apart and embedded not less than 7
inches (178 mm) into a grout filled cell of masonry or into concrete. Base
plates shall be placed in a recess 3/4 inch (19 mm) deep and the width of the
base plate at the edge of a concrete slab, beam/slab or any other type of
construction which uses a masonry surface or concrete slab, or be provided with
an alternate waterstop method as approved by the building official. Alternate
methods of anchorage may be designed by rational analysis by a registered
professional engineer or a registered architect proficient in structural
design.
R4409.5.1.4.2 Where the base plate of a bearing
wall is supported on joists or trusses running perpendicular to the wall and
the studs from the wall above do not fall directly over a joist or truss, a
double base plate or a single base plate supported by a minimum 2x4 inset
ribbon shall be used to support the upper stud wall.
R4409.5.1.5
Top plates.
R4409.5.1.5.1 The top plate of stud bearing walls
shall be doubled and lapped at each intersection of walls and partitions.
R4409.5.1.5.2 Joints shall be lapped not less than
4 feet (1219 mm).
R4409.5.1.6
Corners. Corners of
stud walls and partitions shall be framed solid by not less than three studs.
R4409.5.1.7
Splicing. Studs,
other than end-jointed lumber, shall be spliced only at points where lateral
support is provided.
R4409.5.1.8
Framing types.
R4409.5.1.8.1
Wood framing may be
any one, or a combination of, the following types: Platform, balloon, plank and
beam or pole type.
R4409.5.1.8.2 Exterior stud walls of two-story
buildings shall be balloon-framed with studs continuous from foundation to
second floor ceiling and with second floor joists supported as indicated in
Section R4409.6.3.3. Gable end walls in wood frame buildings shall be balloon
framed with studs continuous from foundation to roof.
Exception: Platform framing is allowed in
buildings over one story in height provided an additional mandatory inspection
for floor level connectors is made before the framing/firestopping inspection.
Gable end walls shall be balloon framed with studs continuous from top floor to
roof.
R4409.5.1.9
Notching.
R4409.5.1.9.1 Studs that carry loads in excess of
75 percent of their capacity shall not be notched or cut.
R4409.5.1.9.2 Studs that carry loads 75 percent or
less of their capacity may be notched to one-third of the depth without limit
of the number of consecutive studs.
R4409.5.1.10
Pipes in walls.
R4409.5.1.10.1 Stud walls and partitions containing
pipes shall be framed to give proper clearance for the piping.
R4409.5.1.10.2 Where walls and partitions containing
piping are parallel to floor joists, the joists shall be doubled and may be spaced
to allow vertical passage of pipes.
R4409.5.1.10.3 Where vertical pipe positions
necessitate the cutting of plates, a metal tie not less than 1inch by 1/8 inch
(25 mm by 3 mm) shall be placed on each side of the plate across the opening
and nailed with not less than two 16d or three 8d nails at each end.
R4409.5.1.11
Headers.
R4409.5.11.1 All headers in bearing walls shall be
designed by rational analysis.
R4409.5.1.11.2 Headers or lintels over stud wall
openings shall have not less than nominal 2-inch (51 mm) bearings.
R4409.5.1.12
Studs joining masonry
or reinforced concrete walls. Where stud walls or partitions join masonry or
concrete walls, such studs shall be secured against lateral movement by bolting
to the masonry or concrete with 1/2 inch (13 mm) diameter anchor bolts with
oversized washer spaced not more than 4 feet (1219 mm) apart and embedded not
less than 5 inches (127 mm) into a grout filled cell or into concrete or as
designed by a registered licensed engineer or registered architect proficient
in structural design using rational analysis.
R4409.5.1.13
Wind bracing.
Exterior stud walls shall be effectively wind-braced in accordance with Section
R4409.9.3. Such bracing shall be designed by a registered licensed engineer or
registered architect proficient in structural design.
R4409.5.1.14 The intermixing of wall framing
described in this section with other types of structural wall systems as
provided in this code shall not be permitted unless such wall framing and
connections are designed by a registered professional engineer or registered
architect proficient in structural design.
R4409.5.1.15 Wall
hung fixtures. Studs in bearing walls, exterior walls and nonbearing partitions
supporting wall hung plumbing fixtures and wall cabinets shall be not less than
2x4, where spaced not more than 16 inches (406 mm) on center or, not less than
2x6, where spaced not more than 24 inches (610 mm) on center.
R4409.5.1.15.1 A
minimum 2x4 horizontal wood member, securely fastened to not less than two such
studs, shall be installed for the attachment of each wall hung plumbing fixture
and wall cabinet.
R4409.5.2 Interior
nonbearing partitions.
R4409.5.2.1 Studs in
interior nonbearing partitions shall be of not less than 2x4 spaced not more
than 24 inches (610 mm) o.c.
R4409.5.2.2 Interior
nonbearing stud partitions may have a single top plate.
R4409.5.2.3 Headers
over openings not exceeding 4 feet (1219 mm) in width may be of 2-inch (51 mm)
nominal thickness placed flat and end-nailed through the studs with no solid
bearing provided.
R44.9.5.2.4 Studs in
interior nonbearing partitions shall be placed with the longer dimension
perpendicular to the partition.
R4409.5.2.5 Stud
partitions subject to frequent wetting shall be of pressure treated wood or
shall be protected with 15-pound (7 kg) asphalt-saturated felt, or by other
approved design methods.
R4409.5.2.6 Wardrobe
units serving as non-bearing partitions, prefabricated or partially
prefabricated may be of 2x2 studs spaced not farther apart than 16 inches (406
mm) provided there is a wood-based structural panel skin-glued or nailed to the
studs.
[1- Default – Not related to structural wind resistance design]
R4409.5.3
Columns and posts.
R4409.5.3.1 Columns and posts shall be framed to
true end bearing, shall be securely anchored against lateral and vertical
forces, and shall be designed by a registered professional engineer or
registered architect proficient in structural design.
R4409.5.3.2 The bottom of columns and posts shall
be protected against deterioration by an approved product or method.
R4409.5.3.3 Columns and posts shall be spliced
only in regions where lateral support is adequately provided about both axes
and is designed by rational analysis. Such design shall be prepared, signed and
sealed by a registered professional engineer or registered architect proficient
in structural design.
R4409.5.3.4 Design dimensions of columns and
posts shall not be reduced by notching, cutting or boring.
SECTION
R4409.6
HIGH-VELOCITY
HURRICANE ZONES — HORIZONTAL FRAMING
R4409.6.1
Size.
R4409.6.1.1 The minimum size of joists and
rafters shall be as set forth in Section R4409.4.
R4409.6.1.2 The design of horizontal framing
other than joists and rafters shall be as set forth in Section R4409.4.1.1.
R4409.6.1.3
Horizontal wood members independently supporting a suspended ceiling shall be
not less than 2x4 and hangers shall be not less than the equivalent of 1x4 wood
members providing proper nailing.
R4409.6.2 Spacing.
Joists and rafters, where a plaster ceiling is directly supported, shall comply
with Section R4411.1.2.3.
[1- Default – Not related to structural wind resistance
design]
R4409.6.3
Bearing.
R4409.6.3.1 Joists and rafters shall have not
less than three inches of bearing, on wood, metal, grout filled masonry or
concrete except as provided in Sections R4409.6.3.2, R4409.6.3.3 and
R4409.6.3.4.
R4409.6.3.2
Masonry and concrete.
R4409.6.3.2.1 Joists and rafters may bear on and be
anchored by steel strap anchor embedded into a grout filled cell of the masonry
or reinforced concrete, as described in Section R4409.8.5.1, to a wood plate
provided such wood plate is of an approved durable species or pressure treated
with an approved preservative and such plate shall be not less than 2x4 and
attached as per Section R4409.5.1.4.1. The net uplift on the plate shall be
limited to 300 pounds per foot (4378 N/m).
R4409.6.3.2.2 Joists and rafters may bear on a
product control approved channel-shaped metal saddle and fastened to the
masonry by a steel strap anchor embedded into a grout filled cell of the
masonry or concrete.
R4409.6.3.2.3 Joists and rafters may bear on
masonry, provided that each joist or rafter in contact with masonry is of an
approved durable species or pressure treated with an approved preservative and
anchored as in Section R4409.6.3.2.2 above.
R4409.6.3.3 Floor joists may butt into a header
beam if effectively toenailed and if an approved metal hanger providing not
less than 3 inches (76 mm) of bearing transmits the vertical load to the top of
the header, provided, however, that approved devices or other approved means of
support may be used in lieu of such bearing. All hangers and devices shall have
Product Approval.
R4409.6.3.4 Ceiling joists may butt into a header
beam, as set forth for floor joists, or approved devices or other approved
means of support may be used in lieu of such bearing. All devices shall have
Product Approval.
R4409.6.3.5 In lieu of the above, bearing and
anchorage may be designed by rational analysis by a registered professional
engineer or registered architect proficient in structural design.
R4409.6.4
Splicing. Horizontal
members shall not be spliced between supports except that properly designed
splices or approved end-jointed lumber may be used.
R4409.6.5
Notching and boring.
R4409.6.5.1 Unless local unit stresses are
calculated on the basis of reduced size, wood members in bending shall not be
cut, notched or bored except as provided in Sections R4409.6.5.1.1 and
R4409.6.5.1.2.
R4409.6.5.1.1 Notches may be cut in the top or
bottom not deeper than one-sixth of the depth not longer than one-third of the
depth of the member and shall not be located in the middle one-third of the
span. Where members are notched at the ends, over bearing points, the notch
depth shall not exceed one-fourth the member depth.
R4409.6.5.1.2 Holes may be bored in the middle
one-third of the depth and length and not larger than one-sixth of the depth.
Space between any two holes in the same joist shall be not less than the depth
of the joist.
R4409.6.5.2 Where necessary to run service pipes
in the space between the ceiling and floor larger than can be accommodated by
the above provision, such ceilings shall be furred or provision made for
headers or beams and/or for changing direction of the joists where the design
permits.
R4409.6.6
Openings.
R4409.6.6.1 Joists shall be doubled adjacent to
openings where more than one joist is cut out or shall be so increased in size
or number as may be needed to meet the stress requirements.
R4409.6.6.2 Headers shall be of the same size as
the joists and where supporting more than one joist shall be double members.
R4409.6.6.3 Headers shall be supported by
approved metal hangers or ledgers or other approved members.
R4409.6.7
Wood entering masonry or reinforced concrete.
R4409.6.7.1 Wood joists, beams or girders which
frame into masonry or reinforced concrete shall have a minimum of 1/2 inch (13
mm) air space at the top, end and sides or shall be preservative pressure treated
or of an approved durable species.
R4409.6.7.2 Where masonry extends above such wood
members, joists shall be fire-cut so the top edge does not enter the masonry
more than 1 inch (25 mm) or shall be provided with wall plate boxes of
self-releasing type or approved hangers.
R4409.6.7.3 Where
joists enter a masonry wall required to be fire resistive, such joists shall be
separated from the opposite side of the wall by at least 4 inches (102 mm) of
solid masonry.
[2- Fire/Life
Safety]
R4409.6.8 Floor joists.
R4409.6.8.1 Floor
joists under all walls or partitions parallel to the joists shall be doubled.
R4409.6.8.2 Doubled
joists may be separated not more than 6 inches (152 mm).
R4409.6.8.3 Floor
joists supporting concrete or grout for tile floors shall have a maximum
spacing of 12 inches (305 mm).
[1- Default – Not
related to structural wind resistance design]
R4409.6.9
Ceiling joists.
R4409.6.9.1 In buildings with pitched roofs the
ceiling joists, where practicable, shall be nailed to the rafters and shall be
designed to carry all imposed loads including but not limited to lateral
thrust.
R4409.6.9.2 Ceiling joists spanning more than 10
feet (3 m) shall be laterally supported at mid-span.
R4409.6.9.3 Ceiling joists shall not be used to
support rafter loads unless the joists and connections are properly designed
for the total load being imposed.
R4409.6.10
Roof framing. The
permit documents shall include roof framing plans showing spacing and spans of
all roof members indicating any fabricated elements to be designed and
furnished by others and shall include the details for support and bearing of
the roof structural system, for the permanent cross/lateral/diagonal bracing
and anchorage required to resist dead, live and wind loads as set forth in
Section R4403.9. The framing plans shall also indicate the uplift forces
applied on the roof, sheathing type, thickness and nailing requirements for the
sheathing. The roof framing plans shall be prepared by and bear the sign and
seal of, a registered professional engineer or registered architect of record
proficient in structural design.
R4409.6.11
Roof joists. Roof
joists may cantilever over exterior walls as limited by the allowable stress,
but the length of such cantilever shall not exceed half the length of the
portion of the joist inside the building; and where the cantilever of tail
joists exceeds 3 feet (914 mm), the roof joist acting as a header shall be
doubled.
R4409.6.12
Roof rafters.
R4409.6.12.1 Hip rafters, valley rafters and ridge
boards shall be provided and shall be not less in size than the largest rafter
framing thereto nor less than required to support the loads.
R4409.6.12.2
Collar ties.
R4409.6.12.2.1 Collar ties and their connections
shall be provided to resist the thrust of rafters and shall be designed by a
registered engineer or registered architect proficient in structural design.
R4409.6.12.2.2 Collar ties shall not be required if
the ridge is designed as a supporting beam. Such design shall be done by a
registered licensed engineer or registered architect proficient in structural
design.
R4409.6.12.2.3 Ceiling joists may serve as collar
ties when properly designed by a registered professional engineer or registered
architect proficient in structural design.
R4409.6.12.3 The actual roof and ceiling dead
loads may be used to resist uplift loads, but the maximum combined dead load
used to resist uplift loads shall not exceed 10) pounds per square foot (479
Pa).
R4409.6.13
Heavy timber construction. Heavy
timber construction of floors or roofs shall comply with the standards in
Section R4409.1.4. All heavy timber construction shall be designed by a
registered professional engineer or registered architect proficient in
structural design to withstand the loads required in Section R4403.
R4409.6.14
Vertically laminated beams.
Vertically laminated built-up beams shall be designed and made up of members
continuous from bearing to bearing.
R4409.6.15
Glued laminated members.
Glued laminated members shall be designed to comply with applicable AITC
standards adopted by this code.
R4409.6.16 Stair
stringers.
R4409.6.16.1 Stair
stringers shall, where practicable, be framed to provide 4 inches (102 mm) of
bearing at the ends.
R4409.6.16.2 Where it
is not practicable to provide such bearing, the stringers shall be hung in
steel hangers of approved type.
R4409.6.16.3 Stair
stringers shall not be notched or cut in the effective area.
R4409.6.16.4 Two
stringers shall be provided for each flight of stairs no more than 36 inches
(914 mm) in width, and an additional stringer shall be provided for each 18
inches (457 mm) of additional stair width except for public stairs where the
number of stringers shall be determined by rational analysis by a registered
professional engineer or registered architect proficient in structural design.
[1- Default – Not
related to structural wind resistance design]
R4409.6.17 Wood trusses.
R4409.6.17.1
Trussed rafters.
Trussed rafters shall be designed by methods admitting of rational analysis by
a registered professional engineer or registered architect proficient in
structural design based on the standards set forth in Section R4409.1.4.
R4409.6.17.1.1 Where steel is used for connecting
wood members, such connectors shall be not less than 20 U.S. gauge and shall be
protected with a zinc coating conforming to the ASTM A361 Standard set forth in
Chapter 43 of this code. Connectors shall have Product Approval or shall be
designed by methods admitting of rational analysis by a registered professional
engineer or registered architect proficient in structural design.
R4409.6.17.1.2 Where a ceiling is to be attached
directly to the underside of trusses, the trusses shall be laterally braced
with continuous 1x4 members nailed with 8d common nails to the upper side of
the bottom chord at panel points but not to exceed 10 feet (3 m) apart. This
lateral bracing shall be restrained at each end and at 20 foot (6 m) intervals.
Drywall may be considered a rigid ceiling in enclosed areas where it is
protected from the elements. The drywall ceiling is not to be considered a
ceiling diaphragm.
R4409.6.17.1.3 Where a ceiling is to be attached to
wood stripping which is nailed to the underside of the bottom chord of trusses
with two 8d common nails at each intersection, stripping shall be not less than
1x3 spaced not more than 24 inches (610 mm) apart. Wood stripping may be
replaced by furring channels. Furring channels shall be a minimum of 7/8 inch
(22 mm) hat shaped channels weighing 287 pounds per 1000 lineal foot (41.4 kg
per 100 m) with minimum based steel of 0.0179 inch (0.445 mm) and complying
with ASTM C 645 attached to trusses with minimum two #6 11/4 inch (32 mm)
screws per intersection. Said stripping or metal furring channels may serve
also as the lateral bracing of the truss bottom chord so as to minimize the
effects of buckling of the bottom chord when subjected to compressive stresses
under reverse load conditions. In addition, the rigid ceiling that is created
by this 1x3 stripping or metal furring channels must also be restrained from
lateral movements, in accordance with the details provided by the architect or
licensed engineer of record.
Exception: Where fire-rated design assembly does
not allow for this specific installation, see Section R4409.6.17.1.2
R4409.6.17.1.4 Where a ceiling is attached to wood
members suspended beneath trusses, the provisions of Section R4409.6.1 shall
apply.
R4409.6.17.2
Prefabricated wood trusses.
Prefabricated wood trusses shall comply with this section.
R4409.6.17.2.1
Design.
R4409.6.17.2.1.1 Prefabricated wood trusses shall be
designed by a registered professional engineer (delegated engineer) and
fabricated in accordance with the National Design Standard for Metal Plate
Connected Wood Truss Construction of the Truss Plate Institute (TPI). The truss
system designer (delegated engineer) shall prepare the truss system shop
drawings. Such shop drawings shall be submitted to the building official for
review and approval. The shop drawings shall meet the following requirements:
1. All shop drawings shall be in
conformity with the architect or engineer of record framing plans unless prior
written approval is obtained from the architect or engineer of record. If
reframing is approved, the architect or engineer of record shall resubmit
revised framing plans to the building official after receiving updated plans from
the delegated engineer showing all adjustments necessary to safely transmit all
applied loads to the foundation.
2. Permanent bracing of individual truss
members may be required on certain members of the trusses to prevent the
members from buckling in the plane normal to the trusses (buckling in the
narrow direction). This bracing shall be designed for both upward and downward
loads and shall be shown on the individual truss drawings [truss engineering
usually shown on 81/2-inches by 11-inch (216 mm by 279 mm) sheets
("A" size drawings)]. The design of this bracing shall be the
responsibility of the delegated engineer. The contractor shall be responsible
for seeing that this bracing is properly installed. This bracing may be in the
form of (but not limited) to "T" bracing of an individual member, or
lateral bracing of a series of members common to a number of trusses. Where
lateral bracing is used, this bracing shall be restrained against lateral
movement, in accordance with details provided by the delegated engineer or by
the architect or professional engineer of record. All details and sections
required to show the size and connections of all secondary members will be
supplied on the delegated engineering plans and shall show all framing,
connections and bracing on one or more primary plans of minimum size 24 inches
by 36 inches (610mm by 914 mm).
3. A size 81/2-inches by 11-inches (216 mm
by 279 mm) cut sheets showing individual member design shall also be furnished
to the architect or engineer of record so that all gravity and uplift loads
shown on these cut sheets can be transferred to the primary plans.
4. The size and location of all plates at
each joint shall be shown on the truss design drawings.
5. The connection between trusses shall be
detailed in the shop drawings. Hip sets shall be detailed in a manner to
indicate all connections according to engineering drawings for the attachment
of skewed members.
6. Truss design drawings shall indicate
the support and minimum bearing of the roof structural system, the permanent
cross/lateral bracing, bracing to transfer member buckling forces to the
structure and all bracing and anchorage required to resist uplift and lateral
forces.
7. Flat and floor trusses must be clearly
marked so that they will be installed right side up. These marks must remain
after the flooring, sheathing and insulation have been installed.
The intent of the above
requirements is to provide all information on framing, connections and bracing
on one composite set of plans approved by the architect or engineer of record
to aid in the review, approval and field inspections for the portion of the
property.
R4409.6.17.2.1.2 Trusses shall be designed for wind
loads per Section R4403, uniformly distributed live, dead and concentrated
loads, and such loads shall be indicated on the roof framing plans and the
truss design drawings. Where a girder or truss is subjected to concentrated
loads or any unusual loading condition, such conditions must be clearly
indicated on the roof framing plans and on the truss design drawings. Where
truss members have been cut, shifted or altered in any manner to meet
construction needs or for any other reason, additional drawings and additional
calculations must be prepared, signed and sealed by the truss designer (a
Florida-delegated engineer). Such additional drawings and calculations must be
approved by the engineer or architect of record and must be submitted to the
building official for review and approval.
R4409.6.17.2.1.3 Roof trusses shall be designed for a
minimum live load of 30 psf (1436 Pa), a minimum dead load of 15 psf (718 Pa)
on the top chord, and a minimum dead load of 10 psf (479 Pa) on the bottom
chord; and wind loads per Section R4409 of this code. Where the roof design is
such that water is not directed to the interior of the roof and there are no
parapets or other roof edge drainage obstructions, roof trusses with slopes of
11/2:12 or greater may be designed for a live load of 20 psf (958 Pa) and a
minimum total load of 45 psf (2155 Pa). Adjustment of the allowable design
stress for load duration shall be in accordance with National Design
Specification for Wood Construction except that load duration factor for wind
loads shall not exceed 1.33.
R4409.6.17.2.1.4 The allowable deflection under live
load for trusses shall not exceed span/360 for plastered ceilings, span/240 for
unplastered finished ceilings, or span/180 for trusses without a ceiling.
R4409.6.17.2.1.5 Flat roof trusses shall be designed
for not less than the loads set forth in Section R4409.6.17.2.1.3 above, except
that the dead load on the top chord may be taken as 10 psf (479 Pa) in lieu of
15 psf (718 Pa), and the total load reduced to 50 psf (2394 Pa). Adjustment of
the allowable design stress for load duration shall be in accordance with
National Design Specification for Wood Construction except that load duration
factor for wind loads shall not exceed 1.33.
R4409.6.17.2.1.6 Where gable end trusses are permitted
in this code, they shall be designed for a minimum live load of 30 psf (1436
Pa) and a minimum dead load of 15 psf (718 Pa) on the top chord. The minimum
load of 10 psf (479 Pa) on the bottom chord may be omitted where continuous
support is provided. In addition, the gable end trusses shall be designed to
sustain wind load as specified in Section R4403 but not less than 30 psf (1436
Pa) perpendicular to the plane of the truss. Such trusses shall use a rationally
designed system to resist lateral wind loads and be anchored to the
substructure at intervals no greater than 4 feet (1219 mm) on center to resist
the uplift forces and shall be designed to transfer the loads to the
substructure. The design of the system used to resist the lateral loads imposed
on the truss shall be prepared by the engineer or architect of record.
R4409.6.17.2.1.7 When girders exceed two members and
when girder reactions exceed the capacity of standard connectors or hangers,
these reactions shall be shown on the drawings and the connection must be
designed, signed and sealed by a registered professional engineer or registered
architect proficient in structural design and such design shall be included as
part of the shop drawings.
R4409.6.17.2.1.8 All trusses shall be properly braced
to act as a system. Such bracing shall be included as part of the design
document.
R4409.6.17.2.2
Materials and specifications.
R4409.6.17.2.2.1 Trusses shall be fabricated applying
the design values listed in the standard Design Values for Wood Construction of
the American Forest and Paper Association.
R4409.6.17.2.2.2 Top and bottom chords shall be of No.
2 grade or better. Web members shall be of No. 3 grade or better. A chord
member is defined as the entire top or bottom truss member which may consist of
shorter spliced pieces.
R4409.6.17.2.2.3 For trusses spanning 20 feet (6 m) or
less, the minimum percentage of grade-marked members among top and bottom
chords shall be 50 percent.
R4409.6.17.2.2.4 For trusses spanning more than 20
feet (6 m) the minimum percentage of grade-marked percent, and there shall be a
minimum of one marked members among top and bottom chords shall be 75 web on
each truss.
R4409.6.17.2.2.5 All lumber shall be 2x4 nominal or
larger, and no 2-inch (51 mm) nominal member shall be less in size than 11/2
inch (38 mm).
R4409.6.17.2.2.6 The moisture content of all lumber
used in wood truss fabrication shall not exceed 19 percent.
R4409.6.17.2.2.7 Connector plates shall be not less
than 20 gauge galvanized steel meeting ASTM A 653/A 653M or A 924/A 924M, and
shall be identified by the manufacturer's stamp. The size and location of all
plates shall be shown on the truss design drawings. Connectors shall have
Product Approval.
R4409.6.17.2.2.8 All connector plates over 3 inches
(76 mm) and 25 percent of 3 inch (76 mm) or less, as per TPI standards, shall
bear the name, logo or other markings, which clearly identify the manufacturer.
Semiannually, plate manufacturers shall certify compliance with the provisions
of Section 6 of the Truss Plate Institute, TPI-95 or latest edition, National
Design Standard for Metal Plate Connected Wood Truss Construction , with
respect to the grade of steel, thickness or gauge of material, and galvanizing
to ASTM G 60 as a minimum. This certification requirement shall be satisfied by
submitting by an approved independent laboratory to the product control
division.
R4409.6.17.2.3
Fabrication.
R4409.6.17.2.3.1 Manufacturers of prefabricated wood
truss assemblies shall obtain a valid certificate of competency from the
authority having jurisdiction.
R4409.6.17.2.3.2 Each truss shall bear the fabricators
stamp on a web member and 75 percent shall be placed so as to be clearly
visible after erection and before placement of ceiling.
R4409.6.17.2.3.3 Multiple member girder trusses shall
be predrilled at the truss plant for connection bolts only. Hanger bolt holes
shall be drilled on-site on location indicated on approved drawings.
R4409.6.17.2.3.4 Each manufacturer or fabricator shall
retain the services of applicable organizations among those listed below for
monthly inspections of the lumber grade used in fabrication. Following each
inspection, a report shall be submitted by the inspection agency to the
authority having jurisdiction. All inspection agencies providing any type of
inspection services shall be approved by the authority having jurisdiction.
For Pine:
Southern Pine Inspection
Bureau or Timber Products Inspection Inc. or other grading agencies with
appropriate jurisdiction.
For Douglas Fir, Hem-Fir
or Fir-Larch:
Western Wood Products
Association or West Coast Lumber Inspection Bureau. Timber Products Inspection
Inc. or other grading agencies with appropriate jurisdiction.
R4409.6.17.2.3.5 In addition, the fabricator shall
employ an approved testing laboratory to conduct inspections of fabrication
compliance. Such inspections shall be made unannounced and at random at least
once a month. Following each inspection, a report on approved forms shall be
submitted by the laboratory to the authority having jurisdiction and such
reports shall bear the date, signature and seal of the supervising
Florida-registered architect or professional engineer.
R4409.6.17.2.3.6 When there is evidence of
noncompliance with the provisions for fabrication set forth in this paragraph
or with the approved plans, the authority having jurisdiction may require the
inspection laboratory to make additional jobsite or plant inspections.
R4409.6.17.2.3.7 The authority having jurisdiction may
require load testing on noncomplying wood trusses. The test results shall be
reported to the authority having jurisdiction.
R4409.6.17.2.3.8 Failure of units tested or receipt of
inspection reports indicating fabrication not in accordance with approved truss
design drawings, or failure to submit required inspection and/or test reports,
shall be cause for suspension or revocation of the certificate of competency of
the manufacturer or fabricator.
R4409.6.17.2.4 Truss
erection.
R4409.6.17.2.4.1 All
trusses shall be erected in accordance with TPI/WTCA BCSI 1 in addition to any
requirements indicated on the approved permit document
R4409.6.17.2.4.2 For
trusses having an overall length of the bottom chord in excess of 35 feet (10.7
m) or 6 feet (1829 mm) overall height erection shall be supervised by either a
registered licensed engineer or registered architect retained by the
contractor. A retainer letter from the registered licensed engineer or
registered architect shall be submitted along with the shop drawings as part of
the permit document.
R4409.6.17.2.4.3
Temporary bracing shall be required during the erection of roof trusses to keep
the trusses in a true plumb position and to prevent toppling of the trusses
during erection, until the roof sheathing is applied. The provisions for
temporary bracing shown in TPI/WTCA BCSI 1 shall be used for this bracing or a
professional engineer or architect shall design the temporary bracing system.
The ultimate responsibility to see this bracing is installed properly during
the erection process lies with the permit holder. This bracing is extremely
important for the protection of life and property during the erection process.
Temporary truss bracing shall always be required.
R4409.6.17.2.4.4 At gable ends, this diaphragm shall
be designed to transmit lateral loads imposed on the gable to roof diaphragms
and/or ceiling diaphragms where available. Where the wall supporting the gable
is not designed to withstand lateral loads independent of the gable (by using
shear walls or other methods), anchorage of the gable to the wall shall be
designed to transmit the loads from the wall to the bracing and the bracing
designed to transmit the lateral loads from the gable and wall to the roof
diaphragms and/or ceiling diaphragms where available. Ceiling diaphragms that
provide lateral support at gable walls shall be designed by the architect or
professional engineer of record, and shall have continuous bottom chord
bracing, end restraints, intermediate restraints and conditions so as to
sufficiently transfer the lateral loads at the top of the gable end walls to
the intersecting shear walls. In no case shall the rigid ceiling as defined in
Section R4409.6.17.1.2 be used as an integral part of the system needed for
lateral bracing of the gable end walls.
R4409.6.17.2.4.5
Where masonry or reinforced concrete extends above wood trusses; trusses shall
be designed so as not to compromise the structural integrity of the masonry or
concrete wall it abuts in the event of collapse caused by fire.
[1- Default – Not
related to structural wind resistance design]
SECTION R4409.7
HIGH-VELOCITY
HURRICANE ZONES — FIRESTOPS
R4409.7.1
Firestopping shall be provided to cut off all concealed draft spaces both
vertical and horizontal.
R4409.7.1.1 Firestops
shall form effective fire barriers between stories and between a story and roof
space.
R4409.7.1.2
Firestopping shall be tightly and securely fitted into place and where of wood,
shall be not less than a nominal 2 inches (51 mm) in thickness.
R4409.7.1.3 Spaces
between chimneys and wood framing shall be solidly filled with mortar or loose
incombustible materials supported on incombustible supports.
R4409.7.1.4
Firestopping shall consist of 2-inch (51 mm) nominal lumber, or two thicknesses
of 1-inch (25 mm) nominal lumber with broken lap joints, or one thickness of
23/32 inch (18 mm) plywood, with joints backed by 23/32 inch (18 mm) plywood,
or other approved materials.
R4409.7.1.5
Draftstopping materials shall be not less than 3/8 inch (9.5 mm) plywood or
other approved materials adequately supported.
R4409.7.1.6 Required
firestops and draftstops shall be continuous, and such continuity shall be
maintained throughout. Penetrations of firestops or draft stops shall be sealed
or protected in an approved manner.
R4409.7.1.7
Ventilation of concealed roof spaces shall be maintained in accordance with
Section R4409.13.3.2.
R4409.7.2
Firestopping shall be installed in wood frame construction in the locations
specified in Sections R4409.7.2.1 through R4409.7.2.6.
R4409.7.2.1 In
concealed spaces of stud walls and partitions including furred spaces at
ceiling and floor levels to limit the maximum dimension of any concealed space
to 8 feet (2438 mm).
R4409.7.2.2 At all
interconnections between concealed vertical and horizontal spaces such as occur
at soffits, drop ceilings, cove ceilings and similar features.
R4409.7.2.3 In
concealed spaces between stair stringers at least once in the middle of each
run, at the top and bottom, and between studs along and in line with adjacent
run of stairs of the run.
R4409.7.2.4 At
openings around vents, pipes, ducts, chimneys and fireplaces at ceiling and
floor levels with approved noncombustible materials, except in the case of
approved metal chimney installation.
R4409.7.2.5 In
concealed spaces created by an assembly of floor joists, firestopping shall be
provided for the full depth of the joists at the ends and over the support.
R4409.7.2.6 Around
the top, bottom and sides of door pockets.
R4409.7.3
Draftstopping. Draftstopping shall be provided in wood frame construction in
the locations specified in Sections R4409.7.3.1 and R4409.7.3.2.
R4409.7.3.1
Floor-ceiling assemblies.
R4409.7.3.1.1 Other
Occupancies. All other buildings, in floor-ceiling assemblies so that
horizontal areas do not exceed 1,000 square feet (93 m2).
R4409.7.3.2 Attics.
R4409.7.3.2.1 Group
R3. None required.
Exceptions:
1. Where corridor walls provide a tenant
separation, draftstopping shall be required above only one of the corridor
walls.
2. Where flat roofs with solid joist
construction are used, draftstopping over tenant separation walls is not
required.
3. Where approved sprinklers are provided,
draftstopping shall be required for attic spaces over 9,000 square feet (836
m2) in area.
[1- Default – Not related to structural wind resistance design]
[2- Fire/Life Safety]
SECTION
R4409.8
HIGH-VELOCITY
HURRICANE ZONES — ANCHORAGE
R4409.8.1 Anchorage shall be continuous from
the foundation to the roof and shall satisfy the uplift requirements of Section
R4403.9.
R4409.8.2
Joists.
R4409.8.2.1 Fire-cuts into a masonry wall shall
be anchored to the concrete beam on which they bear.
R4409.8.2.2 Such anchors shall be spaced not more
than 4 feet (1219 mm) apart and shall be placed at opposite ends across the
building on the same run of joists.
R4409.8.3 Joists shall be nailed to bearing
plates, where such plates occur, to each other where continuous at a lap and to
the studs where such studs are contiguous; and ceiling joists shall be nailed
to roof rafters where contiguous.
R4409.8.4 Every roof rafter and/or roof joist
shall be anchored to the beam or studs on which they bear, and roof rafters
opposing at a ridge shall be anchored across the ridge as set forth in Section
R4409.8.6.
R4409.8.5 Anchorage
to concrete.
R4409.8.5.1 Anchorage designed to resist uplift
forces, securing wood to concrete shall be steel straps embedded in the
concrete minimum of 4 inches (102 mm) with hooking devices to top steel of tie
beam designed to withstand the uplift forces set forth by the design
professional. Straps shall be an approved product. All anchors and related
fasteners shall be galvanized.
R4409.8.5.2 As an alternate to using the straps
described in this section, the building official may approve other anchorage
submitted by a Florida-registered professional engineer or a Florida-registered
architect, proficient in structural design, provided that the information set
forth in Section R4409.8.7(1), (2) and (3) submitted in connection with such
anchors and such anchors and the proposed assembly otherwise comply with the
requirements of this code.
R4409.8.6
Anchorage to wood.
R4409.8.6.1 Anchorage designed to resist uplift
forces, securing wood to wood shall be steel straps nailed to each member and
shall be designed to resist uplift forces set forth by the design professional.
Straps shall be an approved product. All anchors and relative nails shall be
galvanized.
R4409.8.6.2 As an alternate to using straps
described in this section, the building official may approve other anchorage submitted
by a Florida-registered architect or a florida Florida registered professional engineer, proficient in
structural design, provided that the information set forth in Sections
R4409.8.7(1), (2) and (3) submitted in connection with such anchors and such
anchors and the proposed assembly otherwise comply with the requirements of
this code.
R4409.8.7
Testing of anchoring.
Anchoring required by R4409.8. and R4409.8.6 shall be tested under the
following criteria:
1. Concrete to wood straps: Minimum design
uplift load 700 pounds (3114 N), with 4 16d nails with upper end bent over
truss chord and nailed. Nails shall be clinched. Anchors shall have devices to
hook into upper tie beam steel and embedded a minimum of 4 inch (102 mm) in
concrete.
2. Wood to wood straps: Minimum design
uplift 700 lb (3114 N) with four 16d nails in each member.
3. Other anchors: Minimum design uplift
700 pounds (3114 N).
4. The criteria stated in Sections
R4409.8.7(1), (2) and (3) above are minimum requirements for Product Approval.
Anchor design and uplift forces shall be approved site for the inspector to.
SECTION
R4409.9
HIGH-VELOCITY
HURRICANE ZONES — SHEATHING
R4409.9.1
Floor sheathing.
R4409.9.1.1 Floor
sheathing, where a part of a required fire-resistive assembly, shall comply
with a nationally recognized testing agency (Underwriter's Laboratory, Factory
Mutual, etc.).
[2- Fire/Life
Safety]
R4409.9.1.2 The
finish floor shall be tongue-and-grooved not less than nominal one inch (25 mm)
lumber laid perpendicular to the joists with end joints on the joists, or a
sub-floor shall be provided as set forth in Sections R4409.9.1.3, R4409.9.1.4,
R4409.9.1.5, and R4409.9.1.6.
[1- Default – Not
related to structural wind resistance design]
R4409.9.1.3 Square-edged or spaced subflooring
may be used only under a finish floor having a strength equal to or greater
than 1/2 inch (12.7 mm) tongue-and-groove wood strip flooring; and under finish
floors of less strength, a tongue-and-groove or plywood subfloor shall be
required.
R4409.9.1.4 Lumber subflooring shall be not less
than 5/8-inch (17 mm) thick when joists are spaced no more than 16 inches (406
mm) on center nor less than 3/4-inch (19 mm) thick when joists are spaced no
more than 24 inches (610 mm) on center. End joints shall be on joists, joints
shall be staggered and parallel to the joists, and ends at walls and similar
places shall be supported by a ribbon or by blocking.
R4409.9.1.5 Plywood subfloors of C-D grade or
Underlayment grade bonded to wood joist using adhesives meeting the
requirements of ASTM D 3498 shall be applied as indicated in Section
R4409.9.1.6.
R4409.9.1.6 Plywood subflooring shall be
continuous over two or more spans with face grain perpendicular to the
supports. The allowable spans shall not exceed those set forth in Table
R4409.9.1.6.
TABLE
R4409.9.1.6
PLYWOOD
SUBFLOOR1
PANEL
SPAN RATING2 MAXIMUM
PLYWOOD SPAN (IN.)3
32/16 164
40/20 204
48/24 24
For SI: 1 inch = 25.4 mm.
Notes:
1. These values apply
for Sheathing C-D and C-C grades only. Spans shall be limited to values shown,
and reduced for the possible effects of concentrated loads.
2. Span Ratings shall
appear on all panels.
3. Plywood edges shall
have approved tongue-and-groove joints or shall be supported with blocking
unless 1/4 inch minimum thickness underlay is installed or 1/2 inch of approved
cellular or lightweight concrete is installed or unless finish floor is 1-inch
nominal woodstrip. Allowable uniform load based on deflection of 1/360 of span
is 100 pounds per square foot.
4. May be 24 inches if
nominal 1-inch wood strip finish floor is laid at right angles to joists.
R4409.9.1.6.1 Plywood panels shall be nailed to
supports with 6d common nails when up to 1/2 inch (13 mm) thick, 8d common
nails when 19/32 to 3/4 inch (15 to 19 mm) thick and 10d common nails or 8d
ring shank when 11/8 inches (29 mm) thick.
R4409.9.1.6.2 Nail spacing shall be 6 inches (152
mm) o.c. at panel edges and 10 inches (254 mm) o.c. at intermediate supports
R4409.9.1.7 Any other
subfloor panel shall have product control division approval and shall be
installed in accordance with the procedures set forth in the approval.
[1- Default – Not
related to structural wind resistance design]
R4409.9.1.8 Flooring shall be nailed with 8d
common nails up to 3/4 inch (19 mm) thick, and 10d common nails or 8d ring
shank nails when greater than 3/4 inch (19 mm) thick up to 11/8 inches (29 mm)
thick.
R4409.9.1.8.1 Nails shall be hand driven 8d common
nails [(0.131 inch (3.3 mm) diameter by 21/2 (inches (63.5 mm) long with 0.281
inch (7.1 mm) diameter full round head)] or power driven 8d nails of the same
dimensions (0.131 inch diameter by 21/2 inches long with 0.281 inch diameter
full round head). Nails of a smaller diameter or length may be used only when
approved by an architect or licensed engineer and only when the spacing is
reduced accordingly.
R4409.9.1.8.2 Nails shall be hand driven 10d common
nails (0.148 inch (3.8 mm) diameter by 3 inch (76 mm) long with 0.312 inch (7.9
mm) diameter full round head) or power driven 10d nails of the same dimensions
(0.148 inch diameter by 3 inch long with 0.312 inch diameter full round head).
Nails of a smaller diameter or length may be used only when approved by an architect
or licensed engineer and only when the spacing is reduced accordingly.
R4409.9.1.9 Nail spacing shall be 6 inches (152
mm) on center at panel edges and 10 inches (254 mm) on center at intermediate
supports.
R4409.9.1.10 Flooring shall be nailed with 8d
common nails not less than two in each board at each support.
R4409.9.1.11 Floors for heavy timber buildings
shall be sheathed as specified for mill floors in Section R4409.9.13.
R4409.9.1.12 Flooring shall not extend closer than
1/2 inch (12.7 mm) from masonry walls.
R4409.9.1.13 If
resilient flooring is to be applied directly to a plywood subfloor without
separate underlayment, the plywood shall have a top ply of C-plugged grade or
better, and the ply immediately under the face shall be at least C grade unless
the face ply is 1/6 inch (4.2 mm) or more in nominal thickness. Plywood shall
be continuous over two or more spans with face grain perpendicular to supports.
Maximum thickness and maximum joist spacing shall comply with Table R4409.9.1.13.
[1- Default – Not
related to structural wind resistance design]
TABLE
R4409.9.1.13
ALLOWABLE
SPAN FOR PLYWOOD COMBINATION SUBFLOOR UNDERLAYMENT1
(SINGLE FLOOR PANELS)
SPECIES
GROUPS MAXIMUM PLYWOOD SPAN (IN.)2,3
164 204 24 48
1 1/2"
5/8" 3/4"
2,3 5/8"
3/4" 7/8"
4 3/4"
7/8" 1"
1,2 and 3 1
1/8"
For SI: 1 inch = 25.4 mm.
Notes:
1. Applicable underlayment grade, C-C (plugged)
and all grades of sanded Exterior type plywood.
2. Spans shall be limited to values shown, and
reduced for the possible effects of concentrated loads.
3. Allowable uniform load based on deflection of
1/360 of span is 100 pounds per square foot except that total load for 48"
on center is 65 pounds per square foot. Plywood edges shall have approved
tongue-and-groove joints or shall be supported with blocking unless 1/4 inch
minimum thickness underlay is installed or 1/2 inch of approved cellular or
lightweight concrete is placed over the subfloor and the sheathing is rated for
Exposure 1.
4. If a wood finish floor is laid perpendicular
to the joists or supports, thickness shown
for 16-inch and 20-inch
spans may be used for 24-inch spans.
R4409.9.1.14
Underlayment hardboard shall meet the property requirements for 7/32 inch (5.6
mm) and 1/4 inch (6.4 mm) service hardboard and shall be 0.215 +/-0.005 inch
(5.5 +/-0.13 mm) thickness; when supported in subflooring such subflooring
shall comply with the requirements of Sections R4409.9.1.3, R4409.9.1.4,
R4409.9.1.5 and R4409.9.1.6.
[1- Default – Not
related to structural wind resistance design]
R4409.9.1.15
Particleboard floor underlayment shall conform to Type 1-B-1 of the standard
listed in Section R4409.1.4. Underlayment shall be not less than 1/4 inch (6.4
mm) in thickness and shall be installed in accordance with the installation
instructions of the National Particleboard Association.
[1- Default – Not
related to structural wind resistance design]
R4409.9.1.16
Diaphragm boundaries.
All floor sheathing acting as a diaphragm shall be attached to a minimum 2-inch
(51 mm) thick nominal nailer with its depth equal to or one size greater than
the intersecting top chord. The nailer shall be connected to the wall to resist
the gravity loads from the floor, wind pressure/suction from the exterior wall
and the diaphragm forces. The floor sheathing shall be attached to the nailer
to resist the wind pressure/suction from the exterior wall and the diaphragm
forces.
R4409.9.2
Roof sheathing.
R4409.9.2.1 Wood roof sheathing shall be boards
or shall be plywood.
R4409.9.2.2 Board roof sheathing shall have a net
thickness of not less than 3/4 inch (19 mm) when the span is not more than 28
inches (711 mm) or 5/8-inch (17 mm) when the span is not more than 24 inches
(610 mm), shall have staggered joints and shall be nailed with 8d common nails
not less than two in each 6-inch (152 mm) board nor three in each 8 inch (203
mm) board at each support.
R4409.9.2.3 Plywood roof sheathing shall be rated
for Exposure 1, have a minimum nominal thickness of 19/32 inch (21 mm) and
shall be continuous over two or more spans with face grain perpendicular to
supports. Roof sheathing panels shall be provided with a minimum of 2x4
edgewise blocking at all horizontal panel joints with edge spacing in accordance
with manufacturer's specifications, for a distance at least 4 feet (1219 mm)
from each gable end. The allowable spans shall not exceed those set forth in
Table R4409.9.2.3.
TABLE
R4409.9.2.3
ALLOWABLE
SPAN FOR PLYWOOD ROOF SHEATHING1
PANEL
SPAN RATING2 MAXIMUM SPAN
IF MAXIMUM SPAN
WITHOUT
BLOCK
OR OTHER EDGE EDGE SUPPORT
(IN.)
SUPPORTS
(IN.)
32/16 24
24
40/20 40
32
48/24 48
36
For SI: 1 inch = 25.4 mm.
Notes:
1. Values apply to
sheathing grade, C-C and C-D panels.
2. Span Rating appears
on all C-C and C-D panels.
R4409.9.2.4 Plywood panels shall be nailed to
supports with 8d ring shank nails.
R4409.9.2.5 Nail spacing shall be 6 inches (152
mm) on center at panel edges and at intermediate supports. Nail spacing shall
be 4 inches (102 mm) on center at gable ends with either 8d ring shank nails or
10d common nails.
R4409.9.2.5.1 Nails shall be hand driven 8d ring
shank or power driven 8d ring shank nails of the following minimum dimensions:
(a) 0.113 inch (2.9 mm) nominal shank diameter, (b) ring diameter of 0.012 inch
(0.3 mm) over shank diameter, (c) 16 to 20 rings per inch, (d) 0.280 inch (7.1
mm) full round head diameter, (e) 23/8 inch (60.3 mm) nail length. Nails of a
smaller diameter or length may be used only when approved by an architect or
licensed engineer and only when the spacing is reduced accordingly.
R4409.9.2.5.2 Nails at gable ends shall be hand
driven 8d ring shank or power driven 8d ring shank nails of the following
minimum dimensions: (a) 0.113 inch (2.9 mm) nominal shank diameter, (b) ring
diameter of 0.012 inch (0.3 mm) over shank diameter, (c) 16 to 20 rings per
inch, (d) 0.280 inch (7.1 mm) full round head diameter, (e) 23/8 inch (60.3 mm)
nail length or as an alternative hand driven 10d common nails [(0.148 inch (3.8
mm) diameter by 3 inches (76 mm) long with 0.312 inch (7.9 mm) diameter full
round head)] or power driven 10d nails of the same dimensions [0.148 inch (3.8
mm) diameter by 3 inches (76 mm) long with 0.312 inch (8 mm) diameter full
round head]. Nails of a smaller diameter or length may be used only when
approved by an architect or professional engineer and only when the spacing is
reduced accordingly. Other products with unique fastening methods may be substituted
for these nailing requirements as approved by the building official and
verified by testing.
R4409.9.2.5.3 Other products with unique fastening
methods may be substituted for these nailing requirements as approved by the
building official and verified by testing.
R4409.9.2.6 Roof sheathing for heavy timber
construction shall comply with Section R4409.6.13 of this code.
R4409.9.2.7
Diaphragm boundaries.
All roof sheathing acting as a diaphragm shall be attached to a minimum 2-inch
(51 mm) thick nominal member with its depth equal to or one size greater than
the intersecting top chord. This shall be achieved with a continuous structural
subfascia, fascia or blocking at 4 inches (102 mm) on center with nails as
required for the appropriate thickness of sheathing.
R4409.9.2.8 When existing roofs are reroofed to
the point that the existing roofing is removed down to the sheathing, the
existing roof sheathing shall be re-nailed
with 8d common nails [(0.131 inch (3.3 mm) diameter by 21/2 inches (63.5 mm)
long with 0.281 inch (7.9 mm) diameter full round head)]. Nail spacing shall be
6 inches (152 mm) on center at panel edges, 6 inches (152 mm) on center at
intermediate supports and where applicable 4 inches (102 mm) on center over
gable ends and subfascia. Existing fasteners may be used to achieve such
minimum spacing.
R4409.9.3
Storm sheathing.
Exterior stud walls shall be sheathed to resist the racking load of wind as set
forth in Section R4403.9 and the concentrated loads that result from
hurricane-generated wind-borne debris as set forth in Section R4403.16 of this
code and shall be at a minimum any of the following types:
1. Tightly fitted, diagonally placed
boards not less than 5/8 inch (17 mm) thickness, nailed with three 8d common
nails to each support for 1 inch by 6 inch (25 mm by 152 mm) boards and four 8d
common nails for 1 inch by 8 inch (25 mm by 203 mm) boards.
2. Wall sheathing shall be plywood, or
Product Approved structural panel, rated Exposure 1 with a minimum thickness of
19/32 inch (15 mm) and shall be applied to studs spaced not more than 16 inches
(406 mm) on center. Wall sheathing shall be continuous over three or more
supports and shall be nailed to such supports with 8d common nails. Nail
spacing shall not exceed 6 inches (152 mm) on center at panel edges and all
intermediate supports. Nail spacing shall be 4 inches (102 mm) on center at
corner studs, in all cases.
3. When plywood panel, or product approved
structural panel, sheathing is used, building paper and diagonal wall bracing
can be omitted.
4. When siding such as shingles nailed
only to plywood or product approved structural panel sheathing, the panel shall
be applied with face grain across studs.
R4409.9.4
Exterior wall cladding.
R4409.9.4.1 Plywood, if protected with stucco,
may serve for both sheathing and exterior cladding provided:
1. The panel thickness shall be not less
than 19/32 inch (15 mm) and Texture 1-11 panels, and the supporting studs shall
be spaced not more than 16 inches (406 mm) o.c.
2. All joints shall be backed solidly with
2-inch (51 mm) nominal blocking or studs or the joints shall be lapped horizontally
or otherwise watertight.
3. Nailing shall be as set forth in
Section 4409.9.3(2).
R4409.9.4.2 Where storm sheathing is provided in
accordance with Section R4409.9.3, exterior cladding may be one of the
following:
1. Wood siding shall be installed
according to its Product Approval.
2. Wood shingles or shakes attached to the
storm sheathing, and/or to nailing boards or shingle backer securely attached
to the storm sheathing. The minimum thickness of wood shingles or shakes
between nailing boards shall be 3/8 inch (9.5 mm).
3. Hardboard of siding quality for
exterior use shall be applied in accordance with the Product Approval.
SECTION R4409.10
HIGH-VELOCITY
HURRICANE ZONES — FURRING
R4409.10.1 Where the
interior of masonry walls is furred, such furring shall be treated and fire
stopped as herein required and shall be securely fastened to the masonry with
not less than one cut nail in alternate course of block.
[1- Default – Not related to structural wind resistance
design]
[2- Fire/Life Safety]
SECTION
R4409.11
HIGH-VELOCITY
HURRICANE ZONES —
CONNECTORS
R4409.11.1 The allowable loads on all types of
connectors shall be as set forth in the standards listed in Section R4409.1.4
and Table R4409.11.1.
R4409.11.2 Nails, bolts and other metal
connectors that are used in locations exposed to the weather shall be
galvanized or otherwise corrosion resistant.
R4409.11.3 In general, nails shall penetrate the
second member a distance equal to the thickness of the member being nailed thereto.
There shall be not less than two nails in any connection.
R4409.11.4 Except for wood-based structural-use
panels and other laminated members manufactured under technical control and
rigid inspection, gluing shall not be considered an acceptable connector in
lieu of the connectors herein specified.
R4409.11.5 Safe loads and design practice for
types of connectors not mentioned or fully covered herein shall be determined
by the building official before approval.
SECTION
R4409.12
HIGH-VELOCITY
HURRICANE ZONES —
WOOD
SUPPORTING MASONRY
R4409.12.1 Wood shall not support masonry or
concrete except as permitted in Sections R4409.12.2 and R4409.12.3.
R4409.12.2 Wood foundation piles may be used to
support concrete or masonry.
R4409.12.3 Plywood
decking and approved wood panels, wood joists and wood studs supporting such
wood joists may be used to support reinforced concrete slabs, concrete-base
tile and terrazzo floors and lightweight concrete toppings as follows:
1. There shall be an approved moisture
vapor barrier between the concrete or other cementitious materials and the
wood.
2. Wood members supporting concrete shall
be preservative treated in compliance with AWPA Use Category Systems Standard
U1, Commodity Specification A Use Category 4B set forth in Sections R4409.1.4
and R4409.13.
3. Approved wood-based structural-use
panel decking shall be rated for Exposure 1.
4. Wood rafters may support concrete roof
tile.
[1- Default – Not
related to structural wind resistance design]
SECTION
R4409.13
HIGH-VELOCITY
HURRICANE ZONES —
PROTECTION
OF WOOD
R4409.13.1 Wood piles shall be treated with
preservatives as set forth in Section R4404.7.1.2.
R4409.13.2
Preservative treated or durable species wood.
R4409.13.2.1 All wood used in areas of building or
structures where the climatic condition is conducive to deterioration which
would affect the structural safety shall be treated in an approved method with
an approved preservative or shall be of an approved durable species.
R4409.13.2.2 All wood in contact with or embedded
in the ground that supports of permanent structures shall be approved
pressure-treated wood suitable for ground contact use.
Exceptions:
1. Naturally durable wood or
pressure-treated wood may be used in contact with the ground for support of
structures other than buildings and walking surfaces.
2. Untreated wood may be used for supports
where entirely below water level and continuously submerged in fresh water.
R4409.13.2.3 Sleepers and sills on concrete slabs
in contact with the ground, wood joists and the underside of wood structural
floors without joists less than 18 inches (457 mm) above ground; or wood
girders less than 12 inches (305 mm) from exposed ground within the crawl space
under buildings, shall be treated in an approved method with an approved
preservative, or shall be of an approved durable species.
R4409.13.2.4 All wood not separated from and/or in
direct contact with concrete masonry, including sills, sleepers, plates, posts,
columns, beams, girders and furring; shall be treated in an approved method
with and approved preservative, or shall be of an approved durable species.
R4409.13.2.5 The expression "pressure-treated
wood" refers to wood meeting the retention, penetration and other
requirements applicable to the species, product, treatment and conditions of
use in the approved standards of the American Wood Preservers Association
(AWPA) and Quality Control Program for Softwood Lumber, Timber and Plywood
Pressure Treated with Water-borne Preservatives for Ground Contact Use in
Residential and Light Commercial Foundations for the American Wood Preservers
Bureau.
R4409.13.2.6 The expression "durable
wood" refers to the heartwood of the following species with the exception
that an occasional piece with corner sapwood may be included if 90 percent or
more of the width of each side on which it occurs is heartwood:
Decay resistant:
Redwood, Cedars, Black Locust.
Termite Resistant:
Redwood, Bald and Eastern Red Cedar.
R4409.13.2.7 Where durable species of wood are
used as structural members in buildings and structures, the stress grade shall
be not less than that required in Section R4409.4.
R4409.13.2.8 When wood pressure treated with a
water-borne preservative is used in enclosed locations where drying in service
cannot readily occur, such wood shall have a moisture content of 19 percent or
less before being covered with insulation, interior wall finish, floor covering
or other material.
R4409.13.2.9 All wood framing less than 8 inches
(203 mm) from exposed earth in exterior walls that rest on concrete or masonry
foundations shall be approved naturally durable species or pressure-treated
wood.
R4409.13.2.10 All posts, poles and columns embedded
in concrete which is in contact with ground and supporting permanent structures
shall be approved pressure treated wood suitable for ground contact use except
naturally durable wood may be used for posts, poles and columns embedded in
concrete for structures other than buildings and walking surfaces or in
structures where wood is above ground level and not exposed to the weather.
R4409.13.2.11 For conditions not specifically
covered, compliance with American Forest & Paper Product Association Wood
Construction Data #6, Design of Wood Frame Structures for Permanence, shall be
deemed as compliance with this code.
R4409.13.3
Ventilation.
R4409.13.3.1
Ventilation of crawl spaces.
Crawl spaces under buildings without basements shall be ventilated by approved
mechanical means or by openings in foundation walls. Ventilation openings shall
be covered with a corrosion-resistant wire mesh with openings not greater than
1/16 inch (1.6 mm).
R4409.13.3.1.1 Where practicable, ventilating
openings shall be arranged on three sides.
R4409.13.3.1.2 The minimum total area of ventilating
openings shall be 2 square feet (0.19 m2) for each 15 linear feet (4.6 m) or a
fraction thereof of exterior wall. Such opening need not be placed in the front
of the building. Where mechanical ventilation is used, the ventilation rate
shall be at least six air changes per hour.
R4409.13.3.2
Ventilation of attic spaces.
Attic space between ceiling joists and roof rafters shall be effectively cross-ventilated
by approved mechanical means or with vent openings. The ratio of total net free
ventilating area to the area of the ceiling shall be not less than 1/150.
Exception: The venting ratio may be reduced to
1/300 where at least 50 percent of the installed ventilating area is provided
by a ventilation system located in the upper portion of the space to be
ventilated [within 18 inches (457 mm) of ridge]. The balance of the required
ventilation shall be provided by eave or cornice vents.
R4409.13.3.2.1 Where practical, ventilating openings
shall be arranged on three sides.
R4409.13.3.2.2 Where mechanical ventilation is used,
the ventilation rate shall be at least six air changes per hour.
R4409.13.3.2.3 All openings into the attic space of
any habitable building shall be covered with screening, hardware cloth or
equivalent to prevent the entry of birds, squirrels, rodents, etc. The openings
therein shall not exceed 1/8 inch (3.2 mm).
R4409.13.3.2.4 For existing structures that were
built before 1992 without soffit ventilation, and where in the opinion of the
building official the soffit ventilation would be impossible or impractical to
install, the building official may determine the extent to which the existing
structure shall be made to conform to the requirements of this section.
R4409.13.3.2.5
Unvented attic assemblies.
Unvented attic assemblies shall be permitted if all the following conditions
are met:
1. The unvented attic space is completely
contained within the building thermal envelope.
2. No interior vapor retarder is installed
on the ceiling side (attic floor) of the unvented attic assembly.
3. Where wood shingles or shakes are used,
a minimum continuous ¼ inch (6 mm) vented air space separates the shingles or
shakes from the roofing underlayment.
4. One of the following shall be met,
depending on the air permeability of the insulation under the structural roof
sheathing:
a. Air-impermeable insulation only.
Insulation shall be applied in direct contact to the underside of the
structural roof sheathing.
b. Air-permeable insulation only. In
addition to air-permeable insulation installed directly below the structural
sheathing, at least R-5 rigid board or sheet insulation shall be installed
directly above the structural roof sheathing for condensation control.
c. Air-impermeable and air-permeable
insulation. At least R-5 air-impermeable insulation shall be applied in direct
contact to the underside of the structural roof sheathing for condensation
control. The air-permeable insulation shall be installed directly under the
air-impermeable insulation.
R4409.13.4
Debris.
R4409.13.4.1 Before
any new building is erected, all stumps and roots shall be removed from the
soil to a depth of at least 12 inches (305 mm) below the surface of the ground
in the area to be occupied by the building.
[1- Default – Not
related to structural wind resistance design]
R4409.13.4.2 In buildings or portions thereof
having wood first-floor systems, all wood forms which have been used in placing
concrete, if within the ground or less than 18 inches (457 mm) above the
ground, shall be removed before the building is occupied or used for any
purpose.
R4409.13.4.3 Loose or casual wood shall not be
stored in direct contact with the ground under any building, and this space
must be thoroughly cleaned of all wood and debris.
R4409.13.5 Termite
protection. All buildings shall have a pre-construction treatment protection
against subterranean termites. The rules and laws as established by the Florida
Department of Agriculture and Consumer Services shall be deemed as approved
with respect to preconstruction soil treatment for protection against
subterranean termites. A certificate of compliance shall be issued to the
building department by the licensed pest control company that contains the
following statement: "The building has received a complete treatment for
the prevention of subterranean termites. Treatment is in accordance with rules
and laws established by the Florida Department of Agriculture and Consumer
Services."
[1- Default – Not related to
structural wind resistance design]
TABLE
R4409.13.1
NAIL
CONNECTION FOR WOOD MEMBERS
CONNECTION COMMON
NAILS NUMBER
OR SPACING
Joists to sill or
girder, toe nail 16d 2
Bridging to joist, toe
nail 8d 2 each end
1" x 6"
subfloor or less to each joist, face nail 8d
2
Over 1" x 6"
subfloor to each joist, face nail 8d 3
+ 1 for each size increase
2" subfloor to
joist or girder, blind and face nail 16d
2
Sole plate to joist or
blocking, face nail 16d 16"
o.c.
Top or sole plate to
stud, end nailed 16d 2
Stud to sole plate, toe
nail 3d 3 or 2 16d
Doubled studs, face nail
16d
24" o.c.
Doubled top plates, face
nail 16d
16" o.c.
Top plates, laps and
intersections, face nail 16d 2
Continuous header, two
pieces 16 d 16" o.c. along each edge
Ceiling joists to plate,
toe nail 16d 2
Continuous header to
stud, toe nail 16d 3
Ceiling joists, laps
over partitions, face nail 16d 3
Ceiling joists to
parallel rafters, face nail 16d 3
Rafter plate, toe nail 16d
3
1" x 6"
sheathing or less, to each bearing, face nail 8d
2
Over 1" x 6"
sheathing, to each bearing, face nail 8d
3 + 1 for each size increase
Built-up corner studs,
face nail 16d 30" o.c.
Built-up girders and beams 20d 32" o.c. at top and bottom and
staggered, 2 at ends and at each splice
2 inch planks 16d
2 each bearing
For SI: 1 inch = 25.4 mm.
Note: In spacing
specifications, o.c. means "on center."
R4409.13.6 Existing
buildings. Whenever the building official has knowledge of the existence of
termites in any building or structure, he shall notify the owner in writing and
direct that necessary measures be taken for the extermination of the termites
within a reasonable length of time, not to exceed 60 days.
[1- Default – Not
related to structural wind resistance design]
R4409.13.6.1 The building official shall inspect
existing buildings having wood-stud exterior walls for which application for a
permit for exterior wall coverings is made and shall have the authority to
order the uncovering of structural elements for inspection and to require necessary
repairs as a part of such approval for a permit, or may order demolition.
SECTION R4409.14
HIGH-VELOCITY
HURRICANE ZONES — FIRE-RETARDANT WOOD
R4409.14.1
Fire-retardant-treated wood shall be defined as 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, Standard Test
Method for Surface Burning Characteristics of Building Materials , a 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 feet (3 m) beyond the
centerline of the burner at any time during the test.
R4409.14.2 The
allowable unit stresses for fire-retardant-treated wood including fastener
values, shall be developed from an approved method which considers the effects
of anticipated temperatures and humidity to which the fire-retardant wood will
be subjected, the type of treatment and the redrying process.
R4409.14.3 All
fire-retardant-treated wood shall bear an identification mark showing the flame
spread classification thereof issued by an approved agency having a
reexamination service which maintains a continued supervision and inspection
over method of drying. If intended for exterior use, the wood shall be further
identified to indicate suitability for exposure to the weather, as defined in
Section R4409.14.5.
R4409.14.4 Where
fire-retardant-treated wood is exposed to the weather, it shall be further
identified to indicate that there is no increase in the listed flamespread
classification as defined in Section R4409.14.1 when subjected to ASTM D 2898,
Standard Method for Accelerated Weathering of Fire Retardant Treated Wood for
Fire Testing .
R4409.14.5 Where
experience has demonstrated a specific need for use of material of low
hygroscopicity, fire-retardant-treated wood to be subjected to high humidity
conditions shall be identified as Type A to indicate the treated wood has a
moisture content of not over 28 percent when tested in accordance with ASTM D
3201 procedures at 92 percent relative humidity.
R4409.14.6
Fire-retardant-treated wood shall be dried to a moisture content of 19 percent
or less for lumber and 15 percent or less for plywood before use. The
identification mark shall show the method of drying after treatment. When fire
retardant treated wood is air dried after treatment (ADAT) it shall be
protected so that no leaching of chemicals will occur. Fire retardant treated
wood kiln dried after treatment (KDAT) shall not be exposed to a dry bulb
temperature exceeding 160°F (71°C). If required for curing, exterior fire
retardant treated wood can be exposed to elevated temperatures when the moisture
content of the wood does not exceed 19 percent for lumber or 15 percent for
wood structural panels. The curing time shall not exceed 48 hours and the
temperature shall not exceed 210°F (99°C).
[2- Fire/Life Safety]
SECTION
R4409.15
HIGH-VELOCITY
HURRICANE ZONES — WOOD FENCES
R4409.15.1 Wood fences, so located on a property
that by zoning regulations they cannot be used as a wall of a building, shall
be constructed to meet the minimum specifications in Sections R4409.15.2 and
R4409.15.3.
R4409.15.2 Fences not exceeding 6 feet (1829 mm)
in height, shall be constructed to meet the following minimum requirements:
from nominal 4 x 4 x 8 feet (2438 mm) long posts No. 2 Grade or better spaced 4
feet (1219 mm) on center, and embedded 2 feet (610 mm) into a concrete footing
10 inches (254 mm) in diameter and 2 feet (610 mm) deep.
R4409.15.3 Fences not exceeding 5 feet (1524 mm)
or 4 feet (1219 mm) in height shall be constructed as provided in Section
R4409.15.2, except that the spacing of posts may be increased to 5 feet (1524
mm) and 6 feet (1829 mm) on center for these heights, respectively.
SECTION R4409.16
HIGH-VELOCITY
HURRICANE ZONES — FIRE-RETARDANT-TREATED SHAKES AND SHINGLES
R4409.16.1 Treated
shakes and shingles, when impregnated with chemicals by the full-cell vacuum
pressure process, shall be considered fire retardant (classified) roof
coverings when tested in accordance with ASTM E 108, Fire Tests of Roof
Coverings, Including the rain test, ASTM D 2898, Accelerated Weathering of Fire
Retardant Treated wood for Fire Testing. The fire-resistance tests shall
include the intermittent flame test, spread of flame test, burning brand test
and flying brand test. In addition, at the conclusion of the rain test, test
panels shall be subjected to intermittent flame test, burning brand test and
flying brand test.
R4409.16.2 Each
bundle of fire-retardant-treated shakes and shingles shall be identified with
labels indicating the manufacturer, the classification of the material (Class
B) and the quality control agency.
[2- Fire/Life Safety]
SECTION
R4409.17
HIGH-VELOCITY
HURRICANE ZONES — WOOD BLOCKING
R4409.17.1
General.
R4409.17.1.1 Blocking is defined as wood pieces
attached to the roof deck or to each other for the purpose of securing roof
membrane or accessories.
R4409.17.1.2 Wood blocking attachment for
buildings greater than 40 feet (12.2 m) in height must be designed by a
registered architect or professional engineer.
R4409.17.1.3 Wood blocking attachment for
lightweight insulating concrete, gypsum concrete, cementitious wood fiber and
cellular concrete decks shall be designed by a registered architect or licensed
engineer. The decks themselves shall not be used as a wood blocking attachment
substrate.
R4409.17.1.4 Wood blocking shall not be less than
nominal 2x6. The maximum unsupported overhang shall be 2 inches (51 mm). When
the maximum overhang is employed, a nominal 2x8 blocking shall be installed.
R4409.17.1.5 In recover applications, wood
blocking may be reduced to nominal 1 inch (25 mm), providing the attachment is
secured in compliance with this code.
R4409.17.1.6 Sound wood blocking may be reused in
a recover or reroof application, providing the attachment is secured in
compliance with the requirements of this code.
R4409.17.1.7 A fastener shall be placed within 3
inches (761 mm) of the end of each section of wood blocking and a 1/4 inch (6
mm) gap shall be left between each section of wood blocking. No piece of wood
shall have less than two fasteners.
R4409.17.1.8 Fasteners other than nails shall be
predrilled prior to attachment and countersunk to be flush with the surface of
the wood blocking.
R4409.17.1.9 Wood shall be protected according to
Section R4409.13.
R4409.17.1.10 Powder actuated fasteners shall not
be used in wood blocking attachment.
R4409.17.2
Attachment to masonry block and concrete.
R4409.17.2.1 Prior to the installation of wood
blocking to standard weight masonry block, the two top courses shall be solidly
filled with concrete or a tie beam shall be provided as required by this code.
R4409.17.2.2 The fastener's average withdrawal
resistance per lineal foot shall be not less than 250 pounds per foot (3649
N/m) after the application of a 4:1 safety factor.
R4409.17.2.3 The pullover value of the proposed
fastener though the wood blocking shall be not less than 125 percent of the
design load of the proposed fastener. If less, a larger bearing washer shall be
added to the fastener assembly to meet this requirement. Wood blocking
thickness shall be not less than 11/2 inch (38 mm) if a bearing washer is
required.