Sections 2314-2330 High-Velocity
Hurricane Zone.
[Note:
for text of these sections see the 2007 Florida Building Code, Building
available on-line from www.Floridabuilding.org]
Deletion legend:
[1- Default – Not related
to structural wind resistance design]
[2- Fire/Life Safety]
[3- Covered in model base
code]
SECTION 2314
HIGH-VELOCITY HURRICANE ZONES
2314.1 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.
2314.2 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 35 of this code.
2314.3 Fabrication.
2314.3.1 Preparation, fabrication and installation of wood members and the glues, connectors and mechanical devices for fastening shall conform to good engineering practice.
2314.3.2 Any person desiring to manufacture or fabricate wood truss assemblies shall obtain a certificate of competency from the authority having jurisdiction.
2314.4 The following Standards, as set forth in Chapter 35 of this code, are hereby adopted for the design and quality of wood members and their fastenings:
2314.4.1 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
2314.4.2 American Institute of Timber Construction 333 West Hampden Avenue, Englewood, CO 80110 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
2314.4.3 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
2314.4.4 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
2314.4.5 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.
2314.4.6 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.
2314.4.7 American Forest and Paper Association, 1111 19 Street NW,
Washington, D.C. 20036
1. ANSI/AF&PA National Design
Specification for Wood Construction, 2001
2. ANSI/AF&PA Design Values for
Wood Construction, 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
12. ANSI/AF&PA SDPWS-2008 Special
Design Provisions for Wind and Seismic, 2008
2314.4.8 Timber Company, Inc. 2402 Daniels Street, Madison, WI 53704
TECO Performance Standards and Policies for Structural use Panels. PRP-133
2314.4.9 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) 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)].
2314.4.10 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 2315
HIGH-VELOCITY HURRICANE ZONES — QUALITY
2315.1 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.
[3- Covered in model base
code 2303]
2315.1.1
Structural glued-laminated timber shall be manufactured and identified as
required in ANSI/AITC 190.1 as adopted in Section 2314.4.
[3- Covered in model base
code 2303.1.3]
2315.1.2 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 2314.4.
[3- Covered in model base
code 2303.1.4]
2315.1.3 Wood shingles and/or shakes shall be identified by the grademark of an approved grading or inspection bureau or agency.
2315.1.4 Fiberboard for its various uses shall conform to
ANSI/AHA A 194.1.
[3- Covered in model base
code 2303.1.5]
2315.1.5 Hardboard shall conform to AHA Standards as
adopted in Section 2314.4, and shall be identified as to classification.
[3- Covered in model base
code 2303.1.6]
2315.1.6
Particleboard shall conform to the Mat-Formed Particleboard Standard, NIST CS
Section 236, as adopted in Section 2314.4.6, and shall be identified by the
grade mark or certificate of inspection issued by an approved agency.
[3- Covered in model base
code 2303.1.7]
2315.1.7 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 2327.4. 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
approved by the certification agency.
[3- Covered in model base
code 2302.2]
2315.1.8 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.
[3- Covered
in model base code 2303.1.8]
2315.1.9 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).
[3- Covered in model base
code 2303.1.8]
2315.1.10 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 1 inch by 5 inches (25 mm by 127 mm) or 2 inches by 4 inches
(25 mm by 127 mm), or lumber 36 inches (914 mm) and shorter, except that 5/4 by
4 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 2 percent of the pieces of a bundled unit.
[3- Covered in model base
code 2303.1.8]
2315.1.11 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, 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 2315.1.11(2) above maintains a safety factor of 1.5:1. Testing shall be as specified in the testing protocol.
2315.2 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.
[3- Covered in model base
code 2303.1.4]
2315.3 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.
2315.4 Grade and
species.
2315.4.1 All structural wood members not limited by other sections of this chapter shall be of sufficient size and capacity to carry all loads as required by the high-velocity hurricane provisions of Chapter 16 without exceeding the allowable design stresses specified in the National Design Specification for Wood Construction and in compliance with Section 2317.
2315.4.2 Lumber boards used for floor and roof sheathing
shall be in accordance with Table 2315.4.2
[3- Covered in model base code 2304.7]
TABLE 2315.4.2 MINIMUM GRADE
REQUIREMENTS: BOARD GRADES
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SECTION 2316
HIGH-VELOCITY HURRICANE ZONES — SIZES
2316.1 Sizes of lumber, structural glued-laminated timber
and plywood and other wood-based structural panels referred to in this code are
nominal sizes.
[3- Covered in model base
code 2301.3]
2316.2
Computations to determine the required sizes of members shall be based on net
dimensions (actual sizes).
[3- Covered in model base
code 2304.2]
SECTION 2317
HIGH-VELOCITY HURRICANE ZONES —
UNIT STRESSES
2317.1 General.
2317.1.1 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 2314.4.
2317.1.2 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 Chapter 16 (High-Velocity Hurricane Zones). 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.
2317.1.3 Lumber used for studs in interior non-bearing
walls shall have a modulus of elasticity of no less than 0.9 × 106 pounds per
square inch.
[1- Default
– Not related to structural wind resistance design]
2317.1.4 The designer shall specify on the design drawings the size, spacing, species and grade of all load supporting members.
2317.2 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 2314.4.
SECTION 2318
HIGH-VELOCITY HURRICANE ZONE —
VERTICAL FRAMING
2318.1 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.
2318.1.1 Minimum size. Studs shall be not less than 2 inch by 6 inch for exterior walls or 2 inch by 4 inch (51 mm by 102 mm) for interior bearing or load resisting walls unless designed by rational analysis by a registered professional engineer or registered architect proficient in structural design.
2318.1.2 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 professional engineer or registered architect proficient in structural design.
2318.1.3 Placing.
2318.1.3.1 Studs in exterior and bearing walls shall be placed with the longer dimension perpendicular to the wall.
2318.1.3.2 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.
2318.1.3.3 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 2318.1.4.1 when the net wind uplift is up to 500 pounds per foot (7297 N/m).
2318.1.4 Sills and/or
base plates.
2318.1.4.1 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.
2318.1.4.2 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 2 inch by 4 inch (51 mm by 102 mm) inset ribbon shall be used to support the upper stud wall.
2318.1.5 Top plates.
2318.1.5.1 The top plate of stud bearing walls shall be doubled and lapped at each intersection of walls and partitions.
2318.1.5.2 Joints shall be lapped not less than 4 feet (1219 mm).
2318.1.6 Corners. Corners of stud walls and partitions shall be framed solid by not less than three studs.
2318.1.7 Splicing. Studs, other than end-jointed lumber, shall be spliced only at points where lateral support is provided.
2318.1.8 Framing
types.
2318.1.8.1 Wood framing may be any one, or a combination of, the following types: platform, balloon, plank and beam or pole type.
2318.1.8.2 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 2319.3.3. 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.
2318.1.9 Notching.
2318.1.9.1 Studs that carry loads in excess of 75 percent of their capacity shall not be notched or cut.
2318.1.9.2 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.
2318.1.10 Pipes in walls.
2318.1.10.1 Stud walls and partitions containing pipes shall be framed to give proper clearance for the piping.
2318.1.10.2 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.
2318.1.10.3 Where vertical pipe positions necessitate the cutting of plates, a metal tie not less than 1 inch 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.
2318.1.11 Headers.
2318.1.11.1 All headers in bearing walls shall be designed by rational analysis.
2318.1.11.2 Headers or lintels over stud wall openings shall have not less than nominal 2-inch (51 mm) bearings.
2318.1.12 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 professional engineer or registered architect proficient in structural design using rational analysis.
2318.1.13 Wind bracing. Exterior stud walls shall be effectively wind-braced in accordance with Section 2322.3. Such bracing shall be designed by a registered professional engineer or registered architect proficient in structural design.
2318.1.14 The intermixing of wall framing described in this chapter 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.
2318.1.15 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 2 inch by 6 inch (51 mm by 152 mm),
where spaced not more than 24 inches (610 mm) on center.
[1- Default – Not related to structural wind resistance design]
2318.1.15.1 A minimum 2-inch by 4-inch (51 mm by 104 mm)
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.
[1- Default
– Not related to structural wind resistance design]
2318.2 Interior nonbearing partitions.
[1- Default – Not related to structural wind resistance design]
2318.2.1 Studs in interior nonbearing partitions shall be
of not less than 2 inch by 4 inch (51 mm by 104 mm) spaced not more than 24
inches (610 mm) o.c.
[1- Default – Not related to structural wind resistance design]
2318.2.2 Interior nonbearing stud partitions may have a
single top plate.
[1- Default – Not related to structural wind resistance design]
2318.2.3 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.
[1- Default – Not related to structural wind resistance design]
2318.2.4 Studs in interior nonbearing partitions shall be
placed with the longer dimension perpendicular to the partition.
[1- Default – Not related to structural wind resistance design]
2318.2.5 Stud partitions subject to frequent wetting
shall be of pressure treated wood or shall be protected with 15-pound
asphalt-saturated felt, or by other approved design methods.
[1- Default – Not related to structural wind resistance design]
2318.2.6 Wardrobe units serving as nonbearing partitions,
prefabricated or partially prefabricated may be of 2-inch by 2-inch (51 mm by
51 mm) 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]
2318.3 Columns and
posts.
2318.3.1 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.
2318.3.2 The bottom of columns and posts shall be
protected against deterioration by an approved product or method.
[3- Covered in model base code 2304.11.2.7]
2318.3.3 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.
2318.3.4 Design dimensions of columns and posts shall not be reduced by notching, cutting or boring.
SECTION 2319
HIGH-VELOCITY HURRICANE ZONES - HORIZONTAL FRAMING
2319.1 Size.
2319.1.1 The minimum size of joists and rafters shall be as set forth in Section 2317.
2319.1.2 The design of horizontal framing other than joists and rafters shall be as set forth in Section 2317.1.1.
2319.1.3 Horizontal wood members independently supporting
a suspended ceiling shall be not less than 2-inch by 4-inch (51 mm by 102 mm)
and hangers shall be not less than the equivalent of 1-inch by 4-inch (25 mm by
102 mm) wood members providing proper nailing.
[1- Default – Not related
to structural wind resistance design]
2319.2 Spacing. Joists and rafters, where a plaster
ceiling is directly supported, shall comply with Section 2507.2.3.
[1- Default
– Not related to structural wind resistance design]
2319.3 Bearing.
2319.3.1 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 2319.3.2, 2319.3.3 and 2319.3.4.
2319.3.2 Masonry and
concrete.
2319.3.2.1 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 Sections 2321.5.1, 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 2 inch by 4 inch (51 mm by 102 mm) and attached as per Section 2318.1.4.1. The net uplift on the plate shall be limited to 300 pounds per foot (4378 N/m).
2319.3.2.2 Joists and rafters may bear on a Product 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.
2319.3.2.3 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 2319.3.2.2 above.
2319.3.3 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.
2319.3.4 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.
2319.3.5 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.
2319.4 Splicing. Horizontal members shall not be spliced between supports except that properly designed splices or approved end-jointed lumber may be used.
2319.5 Notching and boring.
2319.5.1 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 2319.5.1.1 and 2319.5.1.2.
2319.5.1.1 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.
2319.5.1.2 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.
2319.5.2 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.
2319.6 Openings.
2319.6.1 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.
2319.6.2 Headers shall be of the same size as the joists and where supporting more than one joist shall be double members.
2319.6.3 Headers shall be supported by approved metal hangers or ledgers or other approved members.
2319.7 Wood entering
masonry or reinforced concrete.
2319.7.1 Wood joists, beams or girders which frame into masonry or reinforced concrete shall have a minimum of 1/2-inch (12.7 mm) air space at the top, end and sides or shall be preservative pressure treated or of an approved durable species.
2319.7.2 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.
2319.7.3 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]
2319.8 Floor joists.
2319.8.1 Floor joists under all walls or partitions
parallel to the joists shall be doubled.
[1- Default – Not related
to structural wind resistance design]
2319.8.2 Doubled joists may be separated not more than 6
inches (152 mm).
[1- Default – Not related
to structural wind resistance design]
2319.8.3 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]
2319.9 Ceiling
joists.
2319.9.1 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.
2319.9.2 Ceiling joists spanning more than 10 feet (3 m) shall be laterally supported at midspan.
2319.9.3 Ceiling joists shall not be used to support rafter loads unless the joists and connections are properly designed for the total load being imposed.
2319.10 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 Chapter 16 (High- Velocity Hurricane Zones). 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.
2319.11 Roof joists. Roof joists may cantilever over exterior walls as limited by the allowable stress, but the length of such cantilever shall not exceed one-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.
2319.12 Roof rafters.
2319.12.1 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.
2319.12.2 Collar
ties.
2319.12.2.1 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.
2319.12.2.2 Collar ties shall not be required if the ridge is designed as a supporting beam. Such design shall be done by a registered professional engineer or registered architect proficient in structural design.
2319.12.2.3 Ceiling joists may serve as collar ties when properly designed by a registered professional engineer or registered architect proficient in structural design.
2319.12.3 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).
2319.13 Heavy timber construction. Heavy timber construction of floors or roofs shall comply with the standards in Section 2314.4. 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 Chapter 16 (High-Velocity Hurricane Zones).
2319.14 Vertically laminated beams. Vertically laminated built-up beams shall be designed and made up of members continuous from bearing to bearing.
2319.15 Glued-laminated members. Glued-laminated members shall be designed to comply with applicable AITC standards adopted by this code.
2319.16 Stair stringers.
[1- Default – Not related
to structural wind resistance design]
2319.16.1 Stair stringers shall, where practicable, be
framed to provide 4 inches (102 mm) of bearing at the ends.
[1- Default – Not related to structural wind resistance design]
2319.16.2 Where it is not practicable to provide such
bearing, the stringers shall be hung in steel hangers of approved type.
[1- Default – Not related to structural wind resistance design]
2319.16.3 Stair stringers shall not be notched or cut in
the effective area.
[1- Default – Not related to structural wind resistance design]
2319.16.4 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]
2319.17 Wood trusses.
2319.17.1 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 2314.4.
2319.17.1.1 Where steel is used for connecting wood members, such connectors shall be not less than 20 U.S. gage and shall be protected with a zinc coating conforming to ASTM A 361 set forth in Chapter 35 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.
2319.17.1.2 Where a ceiling is to be attached directly to the underside of trusses, the trusses shall be laterally braced with continuous 1-inch by 4-inch (25 mm by 102 mm) 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.
2319.17.1.3 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 1 inch by 3 inches (25 mm by 76 mm) 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 feet (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 1-1/4 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 1-inch by 3-inch (25 mm by 76 mm) stripping or metal furring channels must also be restrained from lateral movements, in accordance with the details provided by the architect or professional engineer of record.
Exception: Where fire-rated design assembly does not allow for this specific installation, see Section 2319.17.1.2
2319.17.1.4 Where a ceiling is attached to wood members suspended beneath trusses, the provisions of Section 2319.1 shall apply.
2319.17.2 Prefabricated wood trusses. Prefabricated wood trusses shall comply with this section.
2319.17.2.1 Design.
2319.17.2.1.1 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-inch 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 (610 mm 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.
2319.17.2.1.2 Trusses shall be designed for wind loads per Chapter 16 (High-Velocity Hurricane Zones), 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.
2319.17.2.1.3 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 Chapter 16 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.
2319.17.2.1.4 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.
2319.17.2.1.5 Flat roof trusses shall be designed for not less than the loads set forth in Section 2319.17.2.1.3 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.
2319.17.2.1.6 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 Chapter 16 (High-Velocity Hurricane Zones) 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.
2319.17.2.1.7 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.
2319.17.2.1.8 All trusses shall be properly braced to act as a system. Such bracing shall be included as part of the design document.
2319.17.2.2 Materials
and specifications.
2319.17.2.2.1 Trusses shall be fabricated applying the design values listed in the standard Design Values for Wood Construction of the American Forest and Paper Association.
2319.17.2.2.2 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.
2319.17.2.2.3 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.
2319.17.2.2.4 For trusses spanning more than 20 feet (6 m) the minimum percentage of grade-marked members among top and bottom chords shall be 75 percent, and there shall be a minimum of one marked web on each truss.
2319.17.2.2.5 All lumber shall be 2 inches by 4 inches (51 mm by 102 mm) nominal or larger, and no 2 inch (51 mm) nominal member shall be less in size than 1 1/2 inch (38 mm).
2319.17.2.2.6 The moisture content of all lumber used in wood truss fabrication shall not exceed 19 percent.
2319.17.2.2.7 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.
2319.17.2.2.8 All connector plates over 3 inches (76 mm) and 25 percent of 3 inches (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, 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 certification agency.
2319.17.2.3
Fabrication.
2319.17.2.3.1 Manufacturers of prefabricated wood truss assemblies shall obtain a valid certificate of competency from the authority having jurisdiction.
2319.17.2.3.2 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.
2319.17.2.3.3 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.
2319.17.2.3.4 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 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.
2319.17.2.3.5 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.
2319.17.2.3.6 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 job-site or plant inspections.
2319.17.2.3.7 The authority having jurisdiction may require load testing on noncomplying wood trusses. The test results shall be reported to the authority having jurisdiction.
2319.17.2.3.8 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.
2319.17.2.4 Truss erection.
2319.17.2.4.1 All trusses shall be erected in accordance
with TPI/WTCA BCSI 1 in addition to any requirements indicated on the approved
permit document.
[1- Default – Not related
to structural wind resistance design]
2319.17.2.4.2 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 professional engineer or
registered architect retained by the contractor. A retainer letter from the
registered professional engineer or registered architect shall be submitted
along with the shop drawings as part of the permit document.
[1- Default – Not related
to structural wind resistance design]
2319.17.2.4.3 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.
[1- Default – Not related
to structural wind resistance design]
2319.17.2.4.4 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 2319.17.1.2 be used as an integral part of the system needed for lateral bracing of the gable end walls.
2319.17.2.4.5 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 2320
HIGH-VELOCITY HURRICANE ZONES — FIRESTOPS
2320.1 Firestopping shall be provided to cut off all
concealed draft spaces both vertical and horizontal.
[2- Fire/Life Safety]
2320.1.1 Firestops shall form effective fire barriers
between stories and between a story and roof space.
[2- Fire/Life Safety]
2320.1.2 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.
[2- Fire/Life Safety]
2320.1.3 Spaces between chimneys and wood framing shall
be solidly filled with mortar or loose incombustible materials supported on
incombustible supports.
[2- Fire/Life Safety]
2320.1.4 Firestopping shall consist of 2-inch (51mm)
nominal lumber, or two thicknesses of 1 inch (25 mm) nominal lumber with broken
lap joints, or 1 thickness of 23/32 inch (18 mm) plywood, with joints backed by
23/32 inch (18 mm) plywood, or other approved materials.
[2- Fire/Life Safety]
2320.1.5 Draftstopping materials shall be not less than
3/8 inch (9.5 mm) plywood or other approved materials adequately supported.
[2- Fire/Life Safety]
2320.1.6 Required firestops and draftstops shall be
continuous, and such continuity shall be maintained throughout. Penetrations of
firestops or draft stops shall be sealed or proected in an approved manner.
[2- Fire/Life Safety]
2320.1.7 Ventilation of concealed roof spaces shall be
maintained in accordance with Section 2326.3.2.
[2- Fire/Life Safety]
2320.2 Firestopping shall be installed in wood frame
construction in the locations specified in Sections
[2- Fire/Life Safety]
2320.2.1 through 2320.2.6.
[2- Fire/Life Safety]
2320.2.1 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).
[2- Fire/Life Safety]
2320.2.2 At all interconnections between concealed
vertical and horizontal spaces such as occur at soffits, drop ceilings, cove
ceilings and similar features.
[2- Fire/Life Safety]
2320.2.3 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.
[2- Fire/Life Safety]
2320.2.4 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.
[2- Fire/Life Safety]
2320.2.5 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.
[2- Fire/Life Safety]
2320.2.6 Around the top, bottom and sides of door
pockets.
[2- Fire/Life Safety]
2320.3 Draftstopping. Draftstopping shall be provided in
wood frame construction in the locations specified in Sections 2320.3.1 and
2320.3.2.
[2- Fire/Life Safety]
2320.3.1 Floor-ceiling assemblies.
[2- Fire/Life Safety]
2320.3.1.1 Group B and M occupancies. In the
floor-ceiling assemblies above and in line with the tenant separation, when
tenant separation walls do not extend to the floor sheathing above.
[2- Fire/Life Safety]
2320.3.1.2 Groups R1, R2 and R4 occupancies. In floor-ceiling
assemblies separating usable spaces into two or more approximate areas with no
area greater than 500 square feet (46.5 m2). Draftstopping shall be provided
parallel to the main framing members in the floor-ceiling assemblies of
multiple-family dwellings, motels and hotels above and in line with the tenant
separation, when tenant separation walls do not extend to the floor sheathing
above.
[2- Fire/Life Safety]
2320.3.1.3 Other occupancies. All other buildings, in
floor-ceiling assemblies so that horizontal areas do not exceed 1,000 square
feet (93 m2).
[2- Fire/Life Safety]
2320.3.2 Attics.
[2- Fire/Life Safety]
2320.3.2.1 Group R1. In the floor-ceiling assemblies
above and in line with the tenant separation, when tenant separation walls do
not extend to the floor sheathing above.
[2- Fire/Life Safety]
2320.3.2.2 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 9000 square feet (836 m2) in area.
[2- Fire/Life Safety]
2320.3.2.3 Other buildings. In attic spaces so that
horizontal areas do not exceed 3,000 square feet (279 m2).
Exceptions:
1. Where
flat roofs with solid joist construction are used, draftstopping over tenant
separation walls is not required.
2. Where
approved sprinklers are provided, the area may be tripled.
[2-
Fire/Life Safety]
SECTION 2321
HIGH-VELOCITY HURRICANE ZONES — ANCHORAGE
2321.1 Anchorage shall be continuous from the foundation to the roof and shall satisfy the uplift requirements of Section 1620.
2321.2 Joists.
2321.2.1 Fire-cuts into a masonry wall shall be anchored to the concrete beam on which they bear.
2321.2.2 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.
2321.3 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.
2321.4 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 2321.6.
2321.5 Anchorage to
concrete.
2321.5.1 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 approved under the criteria set by the certification agency. All anchors and related fasteners shall be galvanized.
2321.5.2 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 2321.7(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.
2321.6 Anchorage to
wood.
2321.6.1 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 approved under the criteria set by the certification agency. All anchors and relative nails shall be galvanized.
2321.6.2 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 registered professional engineer, proficient in structural design, provided that the information set forth in Section 2321.7(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.
2321.7 Testing of anchoring. Anchoring required by Sections 2321.5 and 2321.6 shall be tested under the following criteria:
1. Concrete to wood straps: Minimum design uplift load 700 pounds (3114 N), with four 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 pounds (3114 N) with 4 16d nails in each member.
3. Other anchors: Minimum design uplift 700 pounds (3114 N).
4. The criteria stated in Section 2321.7(1), (2) and (3) above are minimum requirements for product approval for the certification agency. Anchor design and uplift forces shall be submitted to the certification agency for approval together with sufficient documentation and test data to verify performance. A product approval shall be maintained at the job site for the inspector to compare with the uplift force requirements of the design professional as shown on approved plans.
SECTION 2322
HIGH-VELOCITY HURRICANE ZONES — SHEATHING
2322.1 Floor
sheathing.
2322.1.1 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]
2322.1.2 The finish floor shall be tongue-and-grooved not
less than nominal 1-inch (25 mm) lumber laid perpendicular to the joists with
end joints on the joists, or a subfloor shall be provided as set forth in
Sections 2322.1.3, 2322.1.4, 2322.1.5, and 2322.1.6.
[1- Default
– Not related to structural wind resistance design]
2322.1.3 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.
2322.1.4 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.
2322.1.5 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 2322.1.6.
2322.1.6 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 2322.1.6.
TABLE 2322.1.6 PLYWOOD SUBFLOOR1
|
PANEL SPAN RATING2 |
MAXIMUM PLYWOOD SPAN (IN.)3 |
|
32/16 |
164 |
|
For
SI: 1 inch = 25.4 mm. |
4. May be 24 inches if nominal 1 inch wood strip finish floor is laid at right angles to joists.
2322.1.6.1 Plywood panels shall be nailed to supports with 6d common nails when up to 1/2-inch thick (13 mm), 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.
2322.1.6.2 Nail spacing shall be 6 inches (152 mm) o.c. at panel edges and 10 inches (254 mm) o.c. at intermediate supports.
2322.1.7 Any other subfloor panel shall have
certification agency approval and shall be installed in accordance with the
procedures set forth in the approval.
[1- Default
– Not related to structural wind resistance design]
2322.1.8 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.
2322.1.8.1 Nails shall be hand driven 8d common nails [0.131 inch (3.3 mm) diameter by 2 1/2 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 professional engineer and only when the spacing is reduced accordingly.
2322.1.8.2 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 (3.8m) diameter by 3 inch (76 mm) long with 0.312 inch (7.9 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.
2322.1.9 Nail spacing shall be 6 inches (152 mm) on center at panel edges and 10 inches (254 mm) on center at intermediate supports.
2322.1.10 Flooring shall be nailed with 8d common nails not less than two in each board at each support.
2322.1.11 Floors for heavy timber buildings shall be sheathed as specified for mill floors, Section 2319.13.
2322.1.12 Flooring shall not extend closer than 1/2 inch (13 mm) from masonry walls.
2322.1.13 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 2322.1.13.
[1- Default – Not related
to structural wind resistance design]
TABLE 2322.1.13
ALLOWABLE SPAN FOR PLYWOOD COMBINATION SUBFLOOR UNDERLAYMENT1
(SINGLE FLOOR PANELS)
|
SPECIES GROUPS |
MAXIMUM PLYWOOD SPAN (IN.)2, 3 |
|||
|
164 |
5/84 |
24 |
48 |
|
|
1 |
1/2" |
5/8" |
3/4" |
|
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.
2322.1.14 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
2322.1.3, 2322.1.4, 2322.1.5, and 2322.1.6.
[1- Default
– Not related to structural wind resistance design]
2322.1.15 Particleboard floor underlayment shall conform
to Type 1-B-1 of the standard listed in Section 2314.4. 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]
2322.1.16 Diaphragm boundaries. All floor sheathing acting as a diaphragm shall be attached to a minimum 2-inch-thick (51 mm) 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.
2322.2 Roof
sheathing.
2322.2.1 Wood roof sheathing shall be boards or shall be plywood.
2322.2.2 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 board nor three in each 8-inch (203 mm) board at each support.
2322.2.3 Plywood roof sheathing shall be rated for Exposure 1, have a minimum nominal thickness of 19/32 inch (15 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 2 inch by 4 inch (51 mm by 102 mm) 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 2322.2.3.
2322.2.4 Plywood panels shall be nailed to supports with 8d ring shank nails.
2322.2.5 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.
2322.2.5.1 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) 2-inch (60.3 mm) nail length. 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.
2322.2.5.2 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) 2 3/8 inch (60.3 mm) nail length or as an alternative hand driven 10d common nails [0.148 inch (4 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 (4 mm) diameter by 3 inches (76 mm) long with 0.312-inch-diameter (8 mm) 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.
2322.2.5.3 Other products with unique fastening methods may be substituted for these nailing requirements as approved by the building official and verified by testing.
TABLE 2322.2.3
ALLOWABLE SPAN FOR PLYWOOD ROOF SHEATHING1
|
PANEL SPAN RATING2 |
MAXIMUM SPAN IF BLOCK OR OTHER EDGE SUPPORTS (IN.) |
MAXIMUM SPAN |
|
32/16 |
24 |
24 |
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.
2322.2.6 Roof sheathing for heavy timber construction shall comply with Section 2319.13 of this code.
2322.2.7 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.
2322.2.8 When existing roofs are reroofed to the point that the existing roofing is removed down to the sheathing, the existing roof sheathing shall be renailed with 8d common nails [0.131 inch (3.3 mm) diameter by 2 1/2 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.
2322.3 Storm sheathing. Exterior stud walls shall be sheathed to resist the racking load of wind as set forth in Section 1620 and the concentrated loads that result from hurricane-generated wind-borne debris as set forth in Section 1626 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 inches (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.
2322.4 Exterior wall
cladding.
2322.4.1 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 2322.3(2).
2322.4.2 Where storm sheathing is provided in accordance with Section 2322.3, 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 2323
HIGH-VELOCITY HURRICANE ZONES—FURRING
2323.1 Where the interior of masonry walls is furred,
such furring shall be treated and firestopped 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 2324
HIGH-VELOCITY HURRICANE ZONES— CONNECTORS
2324.1 The allowable loads on all types of connectors shall be as set forth in the standards listed in Section 2314.4 and Table 2324.1.
2324.2 Nails, bolts and other metal connectors that are used in locations exposed to the weather shall be galvanized or otherwise corrosion resistant.
2324.3 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.
2324.4 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.
2324.5 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 2325
HIGH-VELOCITY HURRICANE ZONES—WOOD
SUPPORTING MASONRY
2325.1 Wood shall not support masonry or concrete except as permitted in Sections 2325.2 and 2325.3.
2325.2 Wood foundation piles may be used to support concrete or masonry.
2325.3 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 2314.4 and 2326.
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 2326
HIGH-VELOCITY HURRICANE ZONES —
PROTECTION OF WOOD
2326.1 Wood piles shall be treated with preservatives as
set forth in Section 1823.1.2.
[3- Covered in model base
code 2304.11]
2326.2 Preservative treated or durable species wood.
[3- Covered in model base code 2304.11.2]
2326.2.1 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.
[3- Covered in model base code 2304.11.2]
2326.2.2 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.
[3- Covered in model base
code 2304.11.2.7]
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.
2326.2.3 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.
[3- Covered
in model base code 2304.11.2.4]
TABLE 2324.1
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-inch x 6-inch subfloor or less
to each joist, face nail |
8d |
2 |
|
Over 1-inch x 6-inch subfloor to
each joist, face nail |
8d |
3 + 1 for each size increase |
|
2-inches subfloor to joist or
girder, blind and face nail |
16d |
2 |
|
Sole plate to joist or blocking,
face nail |
16d |
16 inches 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 inches o.c. |
|
Doubled top plates, face nail |
16d |
16 inches o.c. |
|
Top plates, laps and
intersections, face nail |
16d |
2 |
|
Continuous header, two pieces |
16 |
16 inches 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-inch x 6-inch sheathing or less,
to each bearing, face nail |
8d |
2 |
|
Over 1-inch x 6-inch sheathing, to
each bearing, face nail |
8d |
3 + 1 for each size increase |
|
Built-up corner studs, face nail |
16d |
30 inches o.c. |
|
Built-up girders and beams |
20d |
32 inches o.c. At top and bottom and staggered, |
|
2-inch planks |
16d |
2 each bearing |
For SI: 1 inch = 25.4 mm.
NOTE: In spacing specifications, o.c. means "on-center."
2326.2.4 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.
[3- Covered in model base code 2304.11.2
2326.2.5 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). 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.
[3- Covered
in model base code 2304.11.2]
2326.2.6 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.
[3- Covered in model base
code]
2326.2.7 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 2317.
[3- Covered in model base code]
2326.2.8 When wood pressure treated with a waterborne
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.
[3- Covered in model base code 2303.1.8.2]
2326.2.9 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.
[3- Covered in model base code 2304.11.2.2]
2326.2.10 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.
[3- Covered in model base code 2304.11.2.7]
2326.2.11 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.
[3- Covered
in model base code 2303.11.8]
2326.3 Ventilation.
2326.3.1 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).
[3- Covered in model base code 2304.11.9]
2326.3.1.1 Where practicable, ventilating openings shall
be arranged on three sides.
2326.3.1.2 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.
[3- Covered
in model base code 1203.2]
2326.3.2 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.
[3- Covered in model base
code 1203.2]
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.
[3- Covered in model base
code 1203.2]
2326.3.2.1 Where practical, ventilating openings shall be
arranged on three sides.
[3- Covered in model base
code 1203.2]
2326.3.2.2 Where mechanical ventilation is used, the
ventilation rate shall be at least six air changes per hour.
[3- Covered in model base
code 1203.2]
2326.3.2.3 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).
[3- Covered in model base
code 1203.2]
2326.3.2.4 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.
[3- Covered in model base code 1203.2]
2326.4 Debris.
2326.4.1 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]
2326.4.2 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.
2326.4.3 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.
2326.5 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 pre-construction 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."
[3- Covered in model base
code 2304.11.6]
2326.6 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]
2326.6.1 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 2327
HIGH-VELOCITY HURRICANE ZONES—FIRE RETARDANT WOOD
2327.1 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.
[2- Fire/Life Safety]
[3- Covered in model base
code 2303.2]
2327.2 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.
[2- Fire/Life Safety]
[3- Covered in model base
code 2303.2.5]
2327.3 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 2327.5.
[2- Fire/Life Safety]
[3- Covered in model base
code 2303.2.4]
2327.4 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 2322.1
when subjected to ASTM D 2898, Standard Method for Accelerated Weathering of
Fire Retardant Treated Wood for Fire Testing.
[2- Fire/Life Safety]
[3- Covered in model base
code 2303.2.4]
2327.5 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.
[2- Fire/Life Safety]
[3- Covered in model base
code 2303.2.6]
2327.6 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]
[3- Covered in model base
code 2303.2.8]
SECTION 2328
HIGH-VELOCITY HURRICANE ZONE—WOOD FENCES
2328.1 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 2328.2 and 2328.3.
2328.2 Fences not exceeding 6 feet (1829 mm) in height, shall be constructed to meet the following minimum requirements: from nominal 4-inch by 4-inch by 8-feet-long (102 mm by 102 mm by 2438 mm) 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.
2328.3 Fences not exceeding 5 feet (1524 mm) or 4 feet (1219 mm) in height shall be constructed as provided in Section 2328.2, 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 2329
HIGH-VELOCITY HURRICANE ZONES— FIRE-RETARDANT-TREATED SHAKES AND
SHINGLES
2329.1 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.
[2- Fire/Life Safety]
2329.2 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 2330
HIGH-VELOCITY HURRICANE ZONES—WOOD BLOCKING
2330.1 General.
2330.1.1 Blocking is defined as wood pieces attached to the roof deck or to each other for the purpose of securing roof membrane or accessories.
2330.1.2 Wood blocking attachment for buildings greater than 40 feet (12.2 m) in height must be designed by a registered architect or professional engineer.
2330.1.3 Wood blocking attachment for lightweight insulating concrete, gypsum concrete, cementitious wood fiber and cellular concrete decks shall be designed by a registered architect or professional engineer. The decks themselves shall not be used as a wood blocking attachment substrate.
2330.1.4 Wood blocking shall not be less than nominal 2 inches by 6 inches (51 mm by mm). The maximum unsupported overhang shall be 2 inches (51 mm). When the maximum overhang is employed, a nominal 2-inch by 6-inch (51 mm by mm) blocking shall be installed.
2330.1.5 In recover applications, wood blocking may be reduced to nominal 1 inch (25 mm), providing the attachment is secured in compliance with this code.
2330.1.6 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.
2330.1.7 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.
2330.1.8 Fasteners other than nails shall be predrilled prior to attachment and countersunk to be flush with the surface of the wood blocking.
2330.1.9 Wood shall be protected according to Section 2326.
2330.1.10 Powder actuated fasteners shall not be used in wood blocking attachment.
2330.2 Attachment to
masonry block and concrete.
2330.2.1 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.
2330.2.2 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.
2330.2.3 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 1 1/2 inch (38 mm) if a bearing washer is required.