CODES

ADOPTS WITH AMENDMENTS:

International Existing Building Code 2012 (IEBC 2012)

Copyright

Preface

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 Compliance Methods

Chapter 4 Prescriptive Compliance Method

Chapter 5 Classification of Work

Chapter 6 Repairs

Chapter 7 Alterations—Level 1

Chapter 8 Alterations—Level 2

Chapter 9 Alterations—Level 3

Chapter 10 Change of Occupancy

Chapter 11 Additions

Chapter 12 Historic Buildings

Chapter 13 Relocated or Moved Buildings

Chapter 14 Performance Compliance Methods

Chapter 15 Construction Safeguards

Chapter 16 Referenced Standards

Chapter 17 Retrofitting

Appendix A Guidelines for the Seismic Retrofit of Existing Buildings

Appendix B Standard for Rehabilitation

Appendix C Refer to NFPA 914 Code for Fire Protection of Historic Structures 2001 Edition

Chapter C2 Roof Deck Fastening for High-Wind Areas

Resource A Guidelines on Fire Rating of Archaic Materials and Assemblies Reserved

This chapter provides prescriptive methods for partial structural retrofit of an existing building to increase the resistance of gable end walls to out-of-plane wind loads. It is intended for voluntary use and for reference by mitigation programs. The provisions of this chapter do not necessarily satisfy requirements for new construction. Unless specifically cited, the provisions of this chapter do not necessarily satisfy requirements for structural improvements triggered by addition, alteration, repair, change of occupancy, building relocation or other circumstances.

The provisions of this chapter are applicable to buildings that meet all of the following eligibility requirements:

1. The building is occupancy Group R-3 (1-2 family dwellings).

2. The building includes one or more wood-framed gable end walls constructed using platform framing techniques.

3. The building shall have a mean roof height of 35 feet (10 668 mm) or less.

4. The building includes attic-framing members in the area where retrofit members will be installed shall be made of conventional lumber assembled with nails or the like or with truss plates.

5. The wall below a gable end wall being retrofitted shall be made of conventional lumber assembled with nails or the like, or with truss plates, or the wall shall be made of concrete or masonry.

6. Each gable end wall being retrofitted has or will be provided with studs or vertical webs spaced 24 inches (610 mm) on center maximum.

7. Each gable end wall being retrofitted has a maximum height of 16 feet (4877 mm).

8. The building is or would be assigned to risk category I or II in accordance with Table 1604.5 in the Florida Building Code, Building.

9. The ceiling diaphragm of the retrofitted building in the area of the retrofit shall be comprised of minimum 1/2-inch gypsum board, minimum nominal 3/8-inch wood structural panels, or plaster.

10. The roof diaphragm of the building in the area of the retrofit shall be of minimum nominal 4-foot by 8-foot (1219 mm by 2438 mm) paneling made of plywood, oriented strand board, or similar, or boards butted to each other along their long edges and ends.

All modifications required for conformance with this chapter shall be designed and constructed in accordance with the Florida Building Code, Building or Florida Building Code, Residential provisions for new construction except as specifically modified by this chapter.

ADDED STUD. Studs installed in a gable end wall to provide the required minimum spacing between existing wall studs prior to adding any retrofit studs needed to brace or stiffen the gable end wall.

ATTIC-FRAMING MEMBERS. Structural members such as ceiling joists, rafters, and roof trusses that support ceiling diaphragms or roof decking.

BALLOON FRAMING. A type of wall framing where vertical wall framing members of the gable end wall and the rectangular wall below are continuous from the top of the gable end wall to the bottom of the rectangular wall below.

COMPRESSION BLOCK. A piece of lumber used to restrain an existing or retrofit stud against movement or deflection toward the interior of the building, attached to a lateral brace and bearing directly against the primary or retrofit stud.

EXISTING STUD. A stud in a gable end wall that already exists before the installation of added studs or conducting gable end bracing and stiffening using lateral braces or retrofit studs.

GABLE END WALL. The triangular wall segment at a gable end whose framing members may be conventionally framed, balloon framed, or framed with a truss.

GABLE END TRUSS. A roof truss at an exterior wall with lumber members oriented with their wide faces parallel to the plane of the wall.

GUSSET ANGLE BRACKET. Metal connectors intended by the manufacturer to connect materials at right angles to each other supplied by the manufacturer with fasteners.

LATERAL BRACE. A lumber member typically installed horizontally on the top of attic floor framing members or on the bottom of pitched roof framing members used to transfer both compression and tension loads applied by a gable wall existing, added or retrofit stud into either the ceiling or roof diaphragm.

NAIL PLATE. A manufactured metal plate made of galvanized steel with factory punched holes for fasteners. A nail plate may have the geometry of a strap.

PLATFORM FRAMING. A type of wall framing where structural framing members of the gable end wall terminate at or above the top plate on the rectangular wall below the gable end wall.

PRIMARY STUD. An existing or added stud as defined above. A vertical member installed against the gable end wall sheathing and connected to the top and bottom chords of the gable end framing that provides the required minimum spacing of structural members supporting the wall sheathing.

RETROFIT. The process of strengthening or improving buildings or structures, or individual components of buildings or structures for the purpose of making existing conditions better serve the purpose for which they were originally intended or the purpose that current building codes intend.

RETROFIT STUD. A vertical lumber member used to supplement the strength or stiffness of an existing or added (primary) stud.

STUD-TO-PLATE CONNECTOR. A manufactured metal connector designed to connect studs to lumber plates.

All existing lumber framing members to which retrofit components will be attached shall be in sound condition suitable for their purpose. Ceiling and roof diaphragms in the area of lateral braces shall be in sound condition suitable for their purpose.
All new and replacement materials shall comply with the requirements of the Florida Building Code, Building or the Florida Building Code, Residential as applicable.

Materials for retrofitting gable end walls shall comply with Table 1703.3.

TABLE 1703.3
MATERIAL SPECIFICATIONS FOR RETROFITS

ComponentMinimum Size
or Thickness
Minimum Material Grade or TypeMinimum Capacity
All lumber2-inch nominal thickness
Minimum depth will vary
according to application
#2 Spruce-Pine-Fir (S) or betterNot applicable
Gusset angle bracket14 gage thicknessGalvanized sheet steel approved for connecting wood-to-wood,
wood-to-CMU, or wood-to-concrete.
350 pounds uplift
and lateral load
Stud-to-plate connector14 gage thicknessGalvanized sheet steel approved for connecting wood-to-wood.500 pounds uplift
Metal connectors20 gage thicknessGalvanized sheet steel approved for connecting wood-to-wood,
wood-to-CMU, or wood-to-concrete.
Not applicable
Nail plates and straps20 gage thicknessGalvanized sheet steel approved for connecting wood-to-wood.Not applicable
For the purposes of this code, where dimensions of lumber are specified, they shall be deemed to be nominal dimensions.

Fasteners shall meet the requirements of Table 1703.5, Section 1703.5.1, and Section 1703.5.2, and shall be permitted to be screws or nails meeting the minimum length requirement shown in the figures and specified in the tables of this chapter. Fasteners used to secure connectors shall be those approved by the manufacturer.

TABLE 1703.5
NAIL AND SCREW REQUIREMENTS

Minimum Fastener
Length
Fastener TypeShank Diameter
(Neglecting galvanizing)
Minimum and maximum
Minimum
Length of thread
Minimum Head Diameter
11/2 inches#9 screws0.177 inches11/4 inches0.28 inches
8d common nails0.131 inchesNot applicable0.28 inches
3 inches#9 screws0.177 inches11/2 inches0.28 inches
10d common nails0.148 inchesNot applicable0.28 inches
For SI: 1 inch = 25.4 mm.
Unless otherwise indicated in this chapter, screw sizes and lengths shall be in accordance with Table 1703.5. Permissible screws include deck screws and wood screws. Fine threaded screws, finish screws, or drywall screws shall not be permitted.
Unless otherwise indicated in this chapter, nail sizes and lengths shall be in accordance with Table 1703.5.
Metal plate connectors, nail plates, stud-to-plate connectors, straps and anchors shall be manufactured from galvanized steel and be products approved for connecting wood-to-wood or wood-to-concrete as appropriate for the application. Nail plates shall have holes sized for a minimum of 8d or 10d nails or #9 screws.

The strengthening scheme provided by this chapter requires the installation of lateral braces, retrofit studs, and other load path components to supplement existing framing. Figure 1704.1 shows the general schematic arrangement of the various elements. Lateral braces and retrofit studs shall be installed at each primary stud as specified in Sections 1706 and 1707. At each primary stud subject to strengthening, the retrofit configuration shall be determined in accordance with Table 1704.1. Retrofitting shall be in accordance with Section 1705 for installation of added studs where existing ones are too far apart; Section 1706 for the establishment of locations for retrofits and the installation of retrofit studs that strengthen primary studs; Section 1707 for the installation of lateral braces that connect ceiling and roof diaphragms via attic-framing members; Section 1708 for the two methods for the installation of straps that connect the ends of retrofit studs to lateral braces; and Section 1709 for connection of a gable end wall to the wall below.

For SI: 1 inch =25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.

FIGURE 1704.1
GENERAL MEANS OF GABLE END RETROFIT

TABLE 1704.1
RETROFIT CONFIGURATION AS A FUNCTION OF EXPOSURE CATEGORY, DESIGN WIND SPEED, AND STUD HEIGHT

RETROFIT ELEMENTSSIZE AND NUMBER OF RETROFIT ELEMENTS
Stud length limitations based on Exposure, Basic Wind
Speed, and Configuration
Exposure
Category
Max Ultimate Design Wind
Speed, V
ult (3-sec gust)
(Interpolation is not permitted)
Connections of gable end wall to wall below.
On center spacing (Section 1708)
Configurations A, B, C, or D
Gusset angle
bracket
(inches)
Fasteners to secure
sill plate to wall
(inches)
ABCD
D≤ 130 mph39146'-11″10'-11″14'-3″16'-0″
D>130 – 140 mph34126'-7″10'-5″13'-7″16'-0″
D>140 – 150 mph29106'-2″9'-9″12'-10″16'-0″
D>150 – 160 mph2695'-11″9'-1″12'-0″15'-4″
D.>160 – 170 mph2385'-6″8'-7″11'-4″14'-9″
D>170 – 180 mph2075'-2″8'-1″10'-8″14'-2″
C≤ 130 mph46167'-4″11'-6″15'-1″16'-0″
C>130 – 140 mph39147'-0″10'-11″14'-5″16'-0″
C>140 – 150 mph34126'-8″10'-5″13'-8″16'-0″
C>150 – 160 mph30116'-4″9'-10″13'-0″16'-0″
C.>160 – 170 mph2795'-11″9'-3″12'-3″15'-6″
C>170 – 180 mph2485'-7″8'-9″11'-7″15'-0″
B≤ 130 mph63228'-2″12'-10″16'-0″Note a
B>130 – 140 mph54197'-9″12'-2″15'-0″Note a
B>140 – 150 mph47177'-5″11'-8″15'-3″16'-0″
B>150 – 160 mph42157'-1″11'-2″14'-7″16'-0″
B.>160 – 170 mph37136'-10″10'-8″14'-0″16'-0″
B>170 – 180 mph33126'-7″10'-4″13'-6″16'-0″
Retrofit studs Minimum size and number (Section 1706)2 × 42 × 62 × 82 each 2 × 8
Lateral brace above and below (top and bottom) Minimum size and number (Section 1707)2 × 42 × 42 × 42 each 2 × 8
Retrofit Elements for L-bent strap applications
(Section 1708.1.1)
Fasteners at each end for strap connecting retrofit studs to lateral braces using 11/2-inch
long fasteners complying with Table 1703.5 Minimum number
3565 at each end
of each strap
Fasteners to connected compression blocks to lateral braces using 3-inch long fasteners complying with Table 1703.5 Minimum number4675
Retrofit Elements for U-bent strap applications
(Section 1708.1.2)
Fasteners to connect straps to each edge of lateral braces using 11/2 -inch long fasteners
complying with Table 1703.6 Minimum number
3444 at each end
of each strap
For SI: 1 inch =25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
a. Configuration C is allowable.
Along a platform framed gable end wall where an existing stud is longer than 3 feet (914 mm) and the distance (centerline to centerline) between that stud and an adjacent stud that is also longer than 3 feet (914 mm) is greater than 221/2 inches (572 mm), an added stud shall be installed. This requirement also applies to the top truss of a piggyback truss assembly. The length of the stud shall be the maximum length of the stud itself exclusive of the depth of the top chord and bottom chord members. If an existing stud is interrupted by other members, such as by a diagonal in a truss with a gable end, it shall include retrofit stud sections above and below the interrupting member to provide continuity from the top of the bottom chord to the bottom of the top chord of the gable end framing, or wood structural members shall be added to provide this continuity. If a lateral brace is being omitted, as allowed in Section 1707.4.1, then the existing or added stud shall not be required to be continuous from an interruption to the location of the omitted lateral brace. Added studs shall have at minimum the same narrow and wide face dimensions as the existing studs.
Added studs shall be installed with the same orientation as existing studs. Added studs of piggyback trusses shall align with required primary studs in the truss below.
In the case of conventional framing, each end of each required added stud shall be attached to the top and bottom plates. In the case of truss construction, each end of each required added stud shall be attached to the top and bottom chord of the truss. Attachments shall be made by attaching a stud-to-plate metal connector with minimum uplift capacity of 175 pounds fastened with 11/2-inch long fasteners complying with Table 1703.5.
Existing studs longer than 3 feet (914 mm) that extend to only one end of attic-framing members shall be retrofitted using the methods of Section 1706.6. Existing studs that are interrupted shall be retrofitted using the methods of Section 1706.7.

Except as allowed by Section 1706.5, a retrofit stud shall be installed at each primary stud longer than 3 feet (914 mm) where lateral braces can be installed using the methods of Section 1707. The size of retrofit studs shall be as required by Table 1704.1 for the appropriate retrofit configuration. Where straps are installed using the L-bent strap method of Section 1708.1.1, retrofit studs shall extend from the top of the lower lateral brace up to the bottom of the upper lateral brace, except that a maximum gap of 1/8 inch (3 mm), is allowed at the bottom and 1/2 inch (13 mm) at the top. Where straps are installed using the U-bent method of Section 1708.1.2, retrofit studs shall extend beyond the ends of lateral braces such that lateral braces can fully butt against the retrofit studs.

Exception: A retrofit stud need not be added where the distance between it and an adjacent retrofit, primary stud would be less than 141/2 inches (368 mm).
Primary studs of piggyback truss assemblies shall have retrofit studs sized and placed such that a single continuous retrofit stud is installed and fastened to the primary stud of both the lower and upper truss. Added studs shall be placed and fastened in accordance with Section 1705. The bottom chord of the upper truss shall be connected to the retrofit stud using an approved connector with minimum tension capacity of 175 pounds (79 kg).

Retrofit studs and nailers can be placed on either side of primary studs. Retrofit studs shall be installed in accordance with one of the following methods.

For SI: 1 inch = 25.4 mm.

FIGURE 1706.3
PLACEMENT OF RETROFIT STUDS

Retrofit studs shall be placed immediately adjacent to primary studs as indicated in Figure 1706.3(a) such that retrofit studs overlap the edge or side of the primary stud by a minimum of 11/4 inches (368 mm). Fasteners shall be placed in accordance with Section 1706.4.1.
Retrofit studs shall be placed such that the narrow face of retrofit studs butt against primary studs as indicated in Figure 1706.3(b). Retrofit studs shall be attached to primary studs with nail plates as indicated in Figure 1706.3(b). Nail plates shall be spaced and attached in accordance with Section 1706.4.2.
Retrofit studs shall be placed such that the retrofit stud is offset from the primary stud by use of nail plates such that the nail plate can be affixed as indicated in Figure 1706.3(c) and Figure 1706.4.2, provided the fastening conditions of Section 1706.4.2 are met.

Retrofit studs and existing studs shall be connected using minimum 2 × 4 nailers as indicated in Figure 1706.3(d), provided the following conditions are met. Nailers may be comprised of multiple members lengthwise.

1. Both the primary stud and the retrofit stud shall be butted to nailers and both shall be fastened to the nailer with 3-inch fasteners. Fasteners connecting each stud to the nailer shall be spaced 6-inches (152 mm) on center.

2. Fasteners into nailers through the face of either member shall be offset vertically by a minimum of 23/4 inches (70 mm).

3. Fasteners into nailers shall be a minimum of 23/4 inches (70 mm) but not more than 6 inches (152 mm) from the end of the shorter of the primary stud or retrofit stud to which they are fastened.

4. Fasteners shall be placed minimum 1/2 inch (13 mm) from the edges of studs.

Retrofit studs, nail plates, and nailers shall be fastened in accordance with the following.
Where retrofit studs are placed using the methods of Section 1706.3.1 or 1706.3.4, retrofit studs shall be attached to primary studs and nailers shall be attached to primary studs and retrofit studs using minimum 3-inch long fasteners. Fastener penetration into each member shall be a minimum 11/2 inches (38 mm). Fasteners can be installed from either face of studs or nailers. Fasteners shall be a minimum of 23/4-inches (70 mm) on center along through the face of either member along the length of studs and from ends of studs, and a maximum of 6-inches (152 mm) on center, minimum 1/2 inch (13 mm) to edges of studs, and minimum 1 inch (25 mm) across studs. Fasteners into nailers from any direction shall be offset vertically a minimum of 23/4 inches (70 mm). Fasteners shall be a minimum 23/4 inches (70 mm) from ends of lumber.

Where retrofit studs are placed using the methods of Section 1706.3.2 or 1706.3.3, nail plates shall be spaced and attached in accordance with all of the following requirements.

1. Nail plates shall be spaced such that vertical spacing between plates shall be a maximum of 20 inches (508 mm).

2. There shall be at least three fasteners through each nail plate into both the primary and retrofit studs.

3. Fasteners used to secure nail plates to studs shall be a minimum 11/2 inches (38 mm) long and fasteners shall be a minimum of 23/4 inches (70 mm) and a maximum of 6 inches (152 mm) from the ends of retrofit studs.

4. Fasteners placed in nail plates shall be spaced a minimum of 23/4 inches (70 mm) along the length of lumber and 23/4 inches (70 mm) from ends of lumber.

5. Fasteners shall be placed a minimum of a 1/2 inch (13 mm) from the edges of the studs and a maximum of 11/2 inches (38 mm) from the abutting vertical edges of primary and retrofit studs.

Staggered fasteners used to secure nail plates shall be spaced horizontally a minimum of 1/2 inches (13 mm).
For SI: 1 inch = 25.4 mm

FIGURE 1706.4.2
NAIL PLATE FASTENING

The broad face of retrofit studs may be reduced in width by methods of cutting, boring, or notching at any number of locations along their length provided that all of the following conditions are met.

1. The wide face of retrofit studs shall be sized such that the remaining minimum width of the member at each location of reduced width shall not be less than that required by Table 1704.1.

2. The distance between segments of reduced width shall be a minimum of 8 inches (203 mm) and shall be allowable at the ends of retrofit studs.

3. The average spacing of fasteners connecting retrofit studs to existing studs shall be maximum 6 inches (152 mm) on center.

4. The minimum vertical distance between fasteners on studs shall be a minimum of 23/4 inches. (70 mm).

5. Retrofit studs reduced in width shall not be spliced within 12 inches (304.8 mm) of the location of reduced width. Splice members shall not be notched.

Where existing conditions prevent installation of a full length retrofit stud in accordance with Section 1706.1 or 1707.4, the retrofit stud and its associated two lateral braces shall be permitted to be wholly or partially omitted from that location by installation of a ladder assembly for Retrofit Configurations A and B as defined in Table 1704.1 provided all of the following conditions are met. This method is not allowed for Retrofit Configurations C or D.

1. No more than two ladder assemblies are permitted on a single gable end.

2. There shall be at least two retrofit studs and lateral brace assemblies on each side of the location where a retrofit stud is omitted.

3. Where both of the retrofit studs on each side of an omitted retrofit stud would be required by Table 1704.1 to be 2 × 4, they shall both be 2 × 6. Where either retrofit stud on the side of an omitted stud would be required by Table 1704.1 to be 2 × 6, they both shall be 2 × 8. Where either retrofit stud on the side of an omitted stud would be required by Table 1704.1 to be 2 × 8, they both shall be 2 × 10.

4. Lateral braces adjacent to the omitted lateral brace shall be minimum 2 × 6 lumber extended over four roof framing members and be fastened to each of the four attic-framing members crossed, using minimum four (4) 3-inch long fasteners. Fasteners shall be installed in accordance with Section 1706.4.

5. Ladder rungs shall be of minimum 2 × 4 lumber installed horizontally with their wide face oriented horizontally and installed to span between the retrofit studs on either side of the omitted retrofit stud. The edge of the ladder rung shall bear against the primary stud at the location of the omitted retrofit stud. Ladder rungs shall be vertically spaced a maximum of 16-inches (406 mm) on center.

6. Where ladder rungs cross and bear against the primary stud at the location of the omitted retrofit stud, they shall be attached to the primary stud using a stud-to-plate connector with a minimum capacity of 175 pounds (79 kg) in the direction perpendicular to the gable end wall. Ladder rungs shall be attached to the retrofit studs on both sides of the location where the retrofit stud is omitted using two 3-inch long fasteners driven through the retrofit stud and into the end of the ladder rung.

7. Notching of the ladder rungs shall not be permitted unless the net depth of the ladder rung is a minimum of 31/2 inches (89 mm) in the area of the notch.

Where primary studs are interrupted because of existing conditions and where existing conditions permit, a retrofit stud shall be installed that bridges the interruption. It shall be attached to the primary stud both below and above the interruption, sized in accordance with Table 1704.1 for the total length, placed in accordance with Section 1706.3, and attached in accordance with Section 1706.4 along the portion of its length that is in contact with the primary stud.
Where existing conditions are such that a lateral brace installed in accordance with Section 1707 can only be installed at one end of a primary stud that extends to a lateral brace at only a ceiling or a roof diaphragm such that a lateral brace can be installed in accordance with Section 1707, the method of retrofit shall comply with Section 1706.7.

Retrofit studs shall be permitted to be spliced provided all of the following conditions are met.

1. Retrofit studs shall be butted to one another at the splice joint and a minimum 4 foot (1219 mm) length of splice member shall be centered at the butt joint.

2. Lumber splice members shall be nominal 2-inch lumber with the wide face width equal to or wider than the face width of the spliced retrofit studs.

3. Splice members shall be attached to each of the retrofit stud members on each side of the splice with minimum 7 rows of 3 fasteners for a total of 21 fasteners. Rows of fasteners shall be minimum 23/4 inches (70 mm) from the end of the splice member, minimum 23/4 inches (70 mm) from the splice joint and ends of members, and spaced evenly along the 18-inch (457 mm) splice overlap between these two limits.

At each end of a retrofit stud, a lateral brace shall be installed as indicated in Figure 1707.1(1) or Figure 1707.1(3) for trusses and Figure 1707.1(2) or Figure 1707.1(4) for conventionally framed gable end walls. Lateral braces shall be allowed to be omitted in accordance with Section 1706.6 or 1707.4.1. Alternative methods for providing lateral bracing are allowable in accordance with Section 1707.4. Lateral braces shall be minimum 2 × 4 lumber except as required by Section 1707.4.1 or Section 1706.6.

For SI: 1 inch = 25.4 mm

FIGURE 1707.1(1)
TRUSS GABLE END WALL WITH L-BENT STRAPS

For SI: 1 inch = 25.4 mm

FIGURE 1707.1(2)
CONVENTIONALLY FRAME GABLE END WALL WITH L-BENT STRAPS

For SI: 1 inch = 25.4 mm

FIGURE 1707.1(3)
TRUSS GABLE END WALL WITH U-BENT STRAPS

For SI: 1 inch = 25.4 mm

FIGURE 1707.1(4)
CONVENTIONALLY FRAME GABLE END WALL WITH U-BENT STRAPS

Lateral braces shall be placed approximately perpendicular to the attic-framing members and extend so they are attached to a minimum of three attic-framing members. The attic-framing member farthest from the gable end wall shall be a minimum of 6 feet (1829 mm) from the exterior sheathing or siding on the gable end wall. Lateral braces shall be installed with their wide faces across attic-framing members. Where the method of Section 1708.1.1 is used, lateral braces shall butt against the sheathing or siding of the wall. Where the method of Section 1708.1.2 is used, lateral braces shall butt against the retrofit studs.

Exception: Where existing conditions prevent placement of continuous lateral braces on attic-framing members, installation shall be in accordance with Section 1707.4.
Lateral braces shall be attached to attic-framing members and attached to retrofit studs in accordance with this section.
Lateral braces shall be attached to each of the attic-framing members or ridge ties that they cross with a minimum of three (3) 3-inch long fasteners. Fasteners shall be installed at least 1/2 inch (13 mm) from any edge of either the lateral brace or the attic frame member and spaced at least 1 inch (25.4 mm) apart across the width of the lateral brace as shown in Figures 1707.1(1) through 1707.1(4). Lateral braces shall extend a minimum of 23/4 inches (70 mm) beyond the edge of the last attic-framing member to which they are attached.
Attachment of lateral braces to retrofit studs shall be in accordance with Section 1708.

Where ceiling joists or truss bottom chords are deeper than 6 inches (152 mm), an anchor block shall be installed in each space between ceiling members along the length of the lateral brace except for the space next to the gable end wall.

1. An anchor block shall be installed in each space between attic-framing members along the length of the lateral brace except for the space next to the gable end wall.

2. Anchor blocks shall be minimum 15/32-inch plywood, 7/16-inch OSB, or nominal 2-inch thick lumber #2 spruce-pine-fir or better.

3. Anchor blocks shall have minimum wide face dimension equal to the attic-framing members at the location where the anchor block is installed. Anchor blocks shall extend between attic-framing members and butt against them or their truss plates with a maximum gap of 1/8 inch (3 mm).

4. Anchor blocks shall be installed on lateral braces with their wide face on the narrow face of lateral braces. Anchor blocks shall be placed on lateral braces with their attic interior edge flush with the attic interior face of lateral braces. They are permitted to be placed on different edges of lateral braces.

Anchor blocks shall be fastened to lateral braces with a single row of 8d common nail, 10d common nails or #9 screws with minimum penetration into lateral braces equal to the thickness of the anchor block or 1 inch (25.4 mm) whichever is greater. The minimum number of fastener shall be the maximum that can be placed in a single row with minimum 23/4-inches (70 mm) distance between fasteners and 23/4-inches (70 mm) distance to ends of anchor blocks except that the number of fasteners need not exceed three per anchor block made of nominal 2-inch thick lumber. For nominal 2-inch thick lumber anchor blocks, the number of fasteners need not exceed three fasteners per anchor block.

Where existing conditions prevent the placement of lateral braces as specified in Section 1707.2, the alternative installation methods of Sections 1707.4.1, 1707.4.2, and 1707.4.3 shall be permitted.

Where existing conditions prevent installation of lateral braces in accordance with Section 1707.2, lateral braces shall be permitted to be omitted for Retrofit Configurations A and B, as defined in Table 1704.1, provided all of the following conditions are met. This method is not allowed for Retrofit Configurations C or D.

1. Lateral braces on each side of omitted lateral braces shall be 2 × 4 lumber placed approximately perpendicular to the attic-framing members and installed with their wide faces across attic-framing members. They shall be attached to a minimum of four (4) attic-framing members with attachment to the attic-framing member farthest from the gable end wall a minimum of 8 feet (2438 mm) from the exterior sheathing or siding on the gable end wall.

2. The lateral brace on each side of an omitted lateral brace shall be fastened to each attic-framing member that they cross using three (3) 3-inch long fasteners. Fasteners shall be spaced a minimum of 1/2 inch (13 mm) from the edges of the lateral braces, a minimum of 23/4 inches (70 mm) from ends of lateral braces, and a minimum of 1 inch (25.4 mm) from adjacent fasteners.

3. A retrofit stud shall be installed in accordance with Section 1706.4 at the location of the omitted lateral brace. This retrofit stud and both of the retrofit studs on either side of the omitted lateral brace shall be sized in accordance with Table 1704.1 for the largest of the retrofit studs required at any of the three locations.

4. All three retrofit studs shall have their attic interior edges aligned such that they snuggly butt the strong back to be installed between the two lateral braces on either side of the omitted lateral brace.

5. Retrofit studs adjacent to the omitted lateral brace shall be fastened to their corresponding lateral brace using straps in accordance with the L-bent strap method of Section 1708.1.1 except that a compression block is not required. The U-bent strap method of Section 1708.1.2 is not allowed unless U-bent straps are routed around the exterior face of primary studs.

6. A strong back of minimum 2 × 6 lumber shall be installed parallel to the gable end and shall be located on and span between the lateral braces on the two sides of the omitted lateral brace. The strong back shall extend a minimum of 23/4 inches (70 mm) beyond the outer edges of the lateral braces and be snuggly butted against each of the three retrofit studs. The strong back shall be attached to each of the lateral braces on which it rests with four (4) 3- inch fasteners. The fasteners shall be placed a minimum 1/2 inch (13 mm) from all edges, a minimum of 2-inch (51 mm) spacing between fasteners, and a minimum of 23/4 inches (70 mm) from ends of the lumber members.

7. The retrofit stud at the location of the omitted lateral braces shall be fastened to the strong back using a connector with minimum uplift capacity of 800 pounds (363 kg) as specified by the manufacturer for use with spruce-pine-fir or hem-fir lumber and installed such that this capacity is oriented in the direction perpendicular to the gable end wall.

8. Lateral braces at ends of strong backs shall be permitted to be interrupted in accordance with Section 1707.4.2; but shall not be permitted to be shortened using the alternative method of Section 1707.4.3.

For SI: 1 inch = 25.4 mm.

FIGURE 1707.4.1
OMITTED LATERAL BRACE

Where existing conditions prevent the installation of lateral braces of required length in accordance with Section 1707.1, a splice member shall be permitted to be installed to bridge interruptions. Splice members shall be at minimum the same size lumber as the lateral braces they bridge. Although Figure 1707.4.2 illustrates the general methods that can be used where attic-framing members are spaced 24-inches (610 mm) o.c., the methods apply to other on center spacings. Splice members may extend beyond those shown and are allowed to be fastened to the main lateral brace segments farther than shown. Splice members shall be fastened at each end using the number of fasteners equal to the total number that would be required to be placed in total in that part of lateral braces more distant from the gable end wall. For a lateral brace that requires three fasteners at each roof framing members and installation across three roof framing members, the number of fasteners in the splice need not be more than nine fasteners if the interruption is between the gable end wall and the first attic-framing member; six fasteners if between the first and second framing members, and three fasteners if between subsequent interruptions. Fasteners shall be spaced 1/2 inch (13 mm) from the edges of lateral braces, 1 inch from each other, 1/2 inch (13 mm) from the edge of attic members, and minimum 23/4 inches (25.4 mm) from the ends of lateral braces and from the ends of splice members.

For SI: 1 inch = 25.4 mm.

FIGURE 1707.4.2
INTERRUPTED LATERAL BRACES

Where conditions exist that prevent installation of lateral braces in accordance with Section 1707.4.1 or 1707.4.2, lateral braces shall be permitted to be shortened, except where the brace is adjacent to an omitted lateral brace of Section 1707.4.1, provided all of the following conditions are met.

1. The short lateral brace shall be installed across a minimum of two attic-framing members, be attached to an attic-framing member a minimum of 4 feet (1219 mm) from the gable end wall. Where lateral braces are 2 × 4 they shall be fastened to each attic-framing member over which they cross with three (3) 3-inch fasteners. Where lateral braces are 2 × 6 or wider they shall be fastened to each attic-framing member over which they cross with four (4) 3-inch fasteners.

2. An anchor block shall be installed in each space between attic-framing members along the length of the lateral brace except for the space next to the gable end wall.

3. Anchor blocks shall be minimum 15/32-inch plywood, 7/16-inch OSB, or nominal 2-inch thick lumber #2 spruce-pine-fir or better.

4. Anchor blocks shall have minimum wide face dimension equal to the attic-framing members at the location where the anchor block is installed. Anchor blocks shall extend between attic-framing members and butt against them or their truss plates with a maximum gap of 1/8 inch (3 mm).

5. Anchor blocks shall be installed on lateral braces with their wide face on the narrow face of lateral braces. Anchor blocks shall be placed on lateral braces with their attic interior edge flash with the attic interior face of lateral braces. They are permitted to be placed on different edges of lateral braces.

6. Anchor blocks shall be fastened to lateral braces with a single row of 8d common nails, 10d common nails or #9 screws with minimum penetration into lateral braces equal to the thickness of the anchor block or 1 inch (25.4 mm) whichever is greater. The minimum number of fasteners shall be the maximum that can be placed in a single row with minimum 23/4 inches (70 mm) distance between fasteners and 23/4 inches (70 mm) distance to ends of anchor blocks except that the number of fasteners need not exceed seven per anchor block. For nominal 2-inch thick lumber anchor blocks, the number of fasteners need not exceed three fasteners per anchor block.

Where existing conditions prevent installation of lateral braces on top or bottom chords of trusses, they shall be permitted to be installed on diagonal webs or vertical members of trusses provided all of the following conditions are met.

1. Lateral braces shall be positioned as close to the ceiling or roof diaphragms as existing conditions permit without altering trusses or any of their components.

2. Anchor blocks shall be installed between each pair of attic-framing members along the length of the lateral brace except for the framing member space next to the gable end wall. Anchor blocks can be installed on the narrow or wide face of lateral braces.

3. Anchor blocks shall be minimum 15/32-inch plywood, 7/16-inch OSB, or nominal 2-inch thick #2 spruce-pine-fir lumber or better.

4. Anchor blocks shall be sized to extend towards the nearby ceiling or roof diaphragm to within 31/2 inches (89 mm) of the diaphragm. Anchor blocks shall butt against chords or diagonals or vertical webs of trusses or truss plates with a maximum gap of 1/8 inch (3 mm).

5. Anchor blocks shall be fastened to lateral braces with 8d common or 10d common nails or #9 screws with minimum penetration into lateral braces equal to the thickness of the anchor blocks or 1 inch (25.4 mm), whichever is greater. The minimum number of fasteners shall be the maximum that can be placed in a row with a minimum 23/4 inches (70 mm) distance between fasteners and 23/4 inches (70 mm) distance to ends of anchor blocks except that the number need not exceed three fasteners for nominal 2-inch thick lumber anchor blocks.

Where existing conditions prevent installation of lateral braces near the peak of roofs, ridge ties made of minimum 2 × 4 members shall be installed horizontally on faces of trusses to provide anchorage for a required lateral brace. The bottom surfaces of added ridge tie members shall be aligned so that they will support a continuous lateral brace and be installed a maximum of 4 inches (102 mm) below limiting existing conditions for any of the trusses used to support the lateral brace. Ridge ties shall be installed on a minimum of three trusses and on every truss member over which lateral braces pass and be attached to an attic-framing member at least 6 feet (1829 mm) from the exterior sheathing or siding on the gable end wall. Ridge ties shall be placed on alternate sides of trusses. Ridge ties used to support lateral braces shall be fastened to each top chord member of each truss using two (2) 3-inch long fasteners and to any other truss members they cross using three (3) 3-inch long fasteners. Fasteners shall be spaced a minimum 1/2 inch (13 mm) from edges of all members and minimum of 1-inch (25.4 mm) from each other. Lateral braces shall be attached to ridge ties as required by Section 1707.3.1.
Piggyback truss assemblies, trusses composed of two trusses one above the other, shall be retrofitted such that a single continuous retrofit stud is installed and fastened to the primary studs of both the lower and upper truss. Primary studs shall be placed and fastened in accordance with Section 1705. The bottom chord of the upper truss shall be connected to the retrofit stud using a connector with minimum 175 pound (79 kg) uplift capacity.
Where outlookers exist to support a gable roof overhang, the outlookers shall be attached to the gable end truss or rafter using a connector with a minimum 175 pound (79 kg) uplift capacity. Where the end of the outlooker butts against an interior truss or rafter, the end shall be connected to the truss or rafter using a joist hanger or U-shaped metal connector with a minimum capacity of 175 pounds (79 kg).
The top and bottom of each retrofit stud shall be attached to a lateral brace with a minimum 11/4 inches (32 mm) wide approved flat or coil metal straps with pre-punched holes for 10d common or 16d common nails or #9 screws. No attachment is required for the retrofit stud located at an omitted lateral brace location where connectors are in place in accordance with Section 1707.4.1. Straps shall be fastened using the size and number of fasteners in accordance with Table 1704.1. For use of L-bent straps, attachment shall comply with the method of Section 1708.1.1 and for use of U-bent straps with the method of Section 1708.1.2. Either method is allowable at either end of a retrofit stud.

For Configurations A, B and C, retrofit studs shall be attached to lateral braces in accordance with Figure 1708.1.1(1) and Figure 1707.1(1) or 1707.1(2). For Configuration D, retrofit studs shall be attached to lateral braces in accordance with Figure 1708.1.1(2) and Figure 1707.1(1) or Figure 1707.1(2). Attachments shall comply with the following conditions except where attachments of retrofit studs at omitted lateral braces are in conformance with Section 1707.4.1.

1. A strap of the gage specified in Table 1704.1 shall be installed to the retrofit stud and lateral brace such that one end of the strap is applied vertically to the retrofit stud on its vertical narrow face nearest the exterior of the gable end wall, bent 90 degrees, and applied horizontally to the wide horizontal face of the lateral brace.

2. Straps shall be long enough and bent appropriately so that the number of fasteners required by Table 1704.1 can be installed while maintaining a minimum distance of 23/4 inches (70 mm) from fasteners to the end of retrofit studs and long enough to clear the retrofit stud end butting the lateral brace.

3. Straps shall be permitted to be twisted or bent where they transition between the tops of retrofit studs and lateral braces to follow roof pitch. Straps shall be bent only once at a given location, although it is permissible that they be bent or twisted at multiple locations along their length. The bends of straps over the ends of retrofit studs shall be right angles.

4. Compression blocks shall be placed on the lateral braces and butted directly against the primary stud or the retrofit stud. Figure 1707.1(1) (trusses) and Figure 1707.1(2) (conventionally framed) show the placement of a compression block against the existing stud. The minimum contact area between compression blocks and primary or retrofit studs shall be an area equivalent to 11/2 inches by 11/2 inches [2.25 square inches (1452 mm2)]. Angled contact is permissible. Compression blocks shall be allowed to be placed over straps or beside straps.

5. Compression blocks shall be fastened to lateral braces using the number of 3-inch fasteners required by Table 1704.1. Fasteners shall be placed such they are a minimum 23/4 inches (70 mm) from the ends of compression blocks, a minimum 23/4 inches (70 mm) from each other along the length of compression blocks, and a minimum 1/2 inch (13 mm) from edges of both compression blocks and lateral braces. Fasteners securing compression blocks are allowed to penetrate straps.

FIGURE 1708.1.1(1)
L-BENT STRAP METHOD FOR CONFIGURATIONS A, B, AND C

FIGURE 1708.1.1(2)
L-BENT STRAP METHOD FOR CONFIGURATION D

For Configurations A, B and C, retrofit studs shall be attached to lateral braces in accordance with Figures 1708.1.2(1) and Figure 1707.1(3) or 1707.1(4). For Configuration D, retrofit studs shall be attached to lateral braces in accordance with Figures 1708.1.2(2) and Figure 1707.1(3) or 1707.1(4). Attachments shall comply with the following conditions except where attachments of retrofit studs at omitted lateral braces are in conformance with Section 1707.4.1.

1. A strap of the gage specified in Table 1704.1 shall be wrapped around the back edge of the retrofit or primary stud and extended onto the two narrow edges of the lateral brace.

2. Lateral braces shall be placed such that one narrow face of the lateral brace is aligned with one wide face of the primary or retrofit stud and the strap shall be bent such that it is in contact with the narrow edge closest to the gable end wall of the primary or retrofit stud being wrapped.

3. At the back of primary or retrofit studs, the two bends of straps shall be crisp.

4. Lateral braces shall butt snugly against the primary or retrofit stud with a maximum gap of 1/4 inch (6 mm).

5. Straps shall be attached to lateral braces using the number of 11/2 inch long fasteners specified in Table 1704.1. Fasteners for straps shall be placed minimum 23/4 inches (70 mm) from ends of lateral braces.

6. Straps shall be permitted to be twisted or bent where they transition between the tops of retrofit studs and lateral braces that follow roof pitch. Straps shall be bent only once at a given location, although it is permissible that they be bent or twisted at multiple locations along their length.

FIGURE 1708.1.2(1)
U-BENT STRAP METHOD FOR CONFIGURATIONS A, B AND C

FIGURE 1708.1.2(2)
U-BENT STRAP METHOD FOR CONFIGURATION D

Along gable ends where primary studs are longer than 3 feet (914 mm), gable end walls shall be connected to the wall below using the methods prescribed in Section 1709.1.

Truss gable end walls shall be attached to the wall below using gusset angle brackets fastened to the bottom chord of roof trusses and to the wall below and spaced in accordance with Table 1704.1. Fasteners shall be placed a minimum of 5/8 inch (15.875 mm) from edges of lumber. Fasteners shall be permitted to penetrate truss plates. Four fasteners shall be effectively installed through each leg of gusset angles.

Exception: Where existing conditions prevent effective installation of all four fasteners into each leg of a gusset angle bracket, a supplementary gusset angle bracket shall be installed a minimum of 23/4 inches (70 mm) from and a maximum of 8 inches (203 mm) from the one without the four fasteners in each leg. The number of effectively installed fasteners securing the corresponding leg of the supplementary gusset angle bracket shall at least equal the number not effectively installed on the first gusset angle bracket.
Where the wall below a gable end is a wood frame wall, a gusset angle bracket specified by the manufacturer for lumber-to-lumber applications shall be installed using fasteners of the same type supplied/specified by the manufacturer. Fasteners installed in top plates shall extend through the full depth of the lowest top plate.

Where the wall below a gable end wall is a concrete or masonry wall, connections shall be by one of the following methods.

2.1 Where the wall below does not have a sill plate on top of the bond beam, a gusset angle bracket specified by the manufacturer for lumber-to-concrete or lumber-to-masonry applications shall be installed directly to the concrete or masonry of the wall below and to the bottom chord of the truss.

2.2 Where there is a sill plate of any thickness on top of the bond beam a gusset angle bracket specified by the manufacturer for lumber-to-concrete or lumber-to-masonry applications shall be installed on the sill plate with fasteners passing vertically through the gusset angle bracket and sill plate and connecting directly into the concrete or masonry wall below. Fasteners of the same diameter and style supplied/ specified by the gusset manufacturer shall be installed that have sufficient length to penetrate the sill plate and embed into the concrete or masonry to the same depth provided by the fasteners supplied/specified by the gusset angle bracket manufacturer for installation directly into concrete.

2.3 Where there is a sill plate on top of the bond beam that is a minimum 11/2 inches (38 mm) thick, a gusset angle bracket specified by the manufacturer for lumber-to-lumber applications shall be fastened to the sill plate. Gusset angle brackets shall be fastened to the sill plate using four each 11/2-inch (38 mm) long fasteners of the same type supplied/specified by the gusset angle manufacturer for wood connections. Regardless of how well the sill plate may be attached to the wall, it shall be anchored to the wall below on each side of the gusset angle bracket using concrete screws of the same type and size and number as those supplied/specified by the gusset manufacturer for concrete or masonry connections. They shall be embedded into the concrete or masonry to the same depth intended for the fasteners supplied/specified by the manufacturer of gusset angles installed in concrete. Washers of minimum 3/8-inch (9.5 mm) diameter shall be placed under heads of those fasteners. Fasteners shall be placed a minimum of 23/4 inches (70 mm) and a maximum of 8 inches (203 mm) from the required gusset angle bracket.

Conventionally framed gable end walls shall be attached to the wall below in accordance with one of the following methods.

The bottom end of each primary stud of gable end walls shall be connected to bottom members using one of the following methods.

1. Where a sill plate for the gable end wall exists, the bottom end of each primary stud shall be connected to the sill plate using a stud-to-plate metal connector with minimum uplift capacity of 175 pounds (79 kg).

2. Where a wood frame gable end wall has a ceiling joist as the lowest outer member of the gable end wall, the primary studs shall be connected to the joist using a stud-to-plate metal connector with minimum uplift capacity of 175 pounds (79 kg) positioned on the wide face of the joist near the top of the joist so that it extends up the stud where the stud is full width.

The gable end walls shall be connected to the wall below using one of the following methods.

1. Where there is a wood frame wall below a gable end wall and where the gable end wall above has a sill or bottom plate atop the plates of the wall below, the sill of the gable end wall shall be connected to the top plates of the wall below using wood screw fasteners with a minimum shear capacity of 150 pounds (667 N) for 11/2-inches (38 mm) side member thickness. Threads of screws shall substantially engage the lower top plate. Screws shall be placed minimum of 13/4 inches (44 mm) from the edges of lumber and minimum of 23/8 inches (60 mm) from the ends of lumber. The screws shall be installed at the spacing indicated in Table 1704.1.

2. Where a wood frame gable end wall has a ceiling joist as the lowest outer member of the gable end wall, that joist shall be connected to the wall below using the method found in Section 1709.1.1 except the ceiling joist shall be attached to the wall below as required for the bottom chord of the roof truss.

3. Where the wall below a gable end wall is a concrete or masonry wall, the sill or bottom plate of the gable end wall shall be connected to the wall below using 1/4-inch diameter concrete or masonry screws of the same type used for gusset angles and of sufficient length to provide a minimum embedment of 11/2 inches (38 mm) into the concrete of the wall or a minimum 23/4 inches (70 mm) into the masonry of the wall. A washer sized for the diameter of the lag bolt or wood screw shall be placed under the head of each lag bolt. The fasteners shall be installed at the spacing indicated in Table 1704.1.

The retrofits presented in this chapter are specifically intended for platform framed gable end walls and do not apply to balloon framed gable end walls.
Resources