// CODE SNIPPET
708.8.1 Roof-to-Wall Connections for Site-Built Single-Family Residential Structures
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Where required by Section 708.8, the intersection of roof framing with the wall below shall provide sufficient resistance to meet the uplift loads specified in Table 708.8.1, either because of existing conditions or through retrofit measures. As an alternative to an engineered design, the prescriptive retrofit solutions provided in Sections 708.8.1.1 through 708.8.1.7 shall be accepted as meeting the mandated roof-to-wall retrofit requirements.
Exceptions:
- Where it can be demonstrated (by code adoption date documentation and permit issuance date) that roof-to-wall connections and/or roof-to-foundation continuous load path requirements were required at the time of original construction.
- Roof-to-wall connections shall not be required unless evaluation and installation of connections at gable ends or all corners can be completed for 15 percent of the cost of roof replacement.
TABLE 708.8.1
REQUIRED UPLIFT CAPACITIES FOR ROOF-TO-WALL CONNECTIONSa, b (POUNDS PER LINEAR FOOT)
REQUIRED UPLIFT CAPACITIES FOR ROOF-TO-WALL CONNECTIONSa, b (POUNDS PER LINEAR FOOT)
| ULTIMATE DESIGN WIND SPEED, Vult | ROOF SPAN (feet) | OVERHANGS | |||||||
| 12 | 20 | 24 | 28 | 32 | 36 | 40 | |||
| Within 6 feet of building corner | 85 | -69.85 | -116.42 | -139.70 | -162.99 | -186.27 | -209.55 | -232.84 | -27 |
| 90 | -82.67 | -137.78 | -165.34 | -192.90 | -220.45 | -248.01 | -275.57 | -30.3 | |
| 100 | -110.51 | -184.18 | -221.01 | -257.85 | -294.68 | -331.52 | -368.36 | -37.4 | |
| 110 | -141.27 | -235.45 | -282.55 | -329.64 | -376.73 | -423.82 | -470.91 | -45.3 | |
| 120 | -174.97 | -291.62 | -349.94 | -408.26 | -466.59 | -524.91 | -583.23 | -53.9 | |
| 130 | -211.60 | -352.66 | -423.19 | -493.72 | -564.26 | -634.79 | -705.32 | -63.2 | |
| 140 | -251.15 | -418.59 | -502.31 | -586.02 | -669.74 | -753.46 | -837.18 | -73.3 | |
| 150 | -293.64 | -489.40 | -587.28 | -685.16 | -783.04 | -880.92 | -978.80 | -84.2 | |
| 170 | -387.40 | -645.67 | -774.81 | -903.94 | -1033.08 | -1162.21 | -1291.35 | -108 | |
| Greater than 6 feet from building corner | 85 | -39.10 | -65.17 | -78.20 | -91.24 | -104.27 | -117.30 | -130.34 | -27 |
| 90 | -48.20 | -80.33 | -96.39 | -112.46 | -128.52 | -144.59 | -160.66 | -30.3 | |
| 100 | -67.95 | -113.24 | -135.89 | -158.54 | -181.19 | -203.84 | -226.49 | -37.4 | |
| 110 | -89.78 | -149.63 | -179.55 | -209.48 | -239.40 | -269.33 | -299.25 | -45.3 | |
| 120 | -113.68 | -189.47 | -227.37 | -265.26 | -303.16 | -341.05 | -378.94 | -53.9 | |
| 130 | -139.67 | -232.78 | -279.34 | -325.90 | -372.45 | -419.01 | -465.57 | -63.2 | |
| 140 | -167.74 | -279.56 | -335.47 | -391.38 | -447.29 | -503.21 | -559.12 | -73.3 | |
| 150 | -197.88 | -329.80 | -395.76 | -461.72 | -527.68 | -593.64 | -659.60 | -84.2 | |
| 170 | -264.41 | -440.68 | -528.81 | -616.95 | -705.08 | -793.22 | -881.35 | -108 | |
For SI: 1 foot = 304.8 mm; 1 pound per linear foot = 1.488 kg/m; 1 mile per hour = 0.305 m/s.
- The uplift loads are pounds per lineal foot of building length. For roof uplift connections multiply by 1.33 for framing spaced 16-inches on center and multiply by 2 for framing spaced 24-inches on center.
- The uplift loads do not account for the effects of overhangs. The magnitude of the above loads shall be increased by adding the overhang loads found in the table. The overhang loads are also based on framing spaced 12-inches on center. The overhang loads given shall be multiplied by the overhang projection and added to the roof uplift value in the table.
- For Ultimate design wind speeds, Vult, greater than 170 mph, wind uplift forces shall be determined in accordance with Florida Building Code, Residential, Section R802.2 or ASCE 7.
- Ultimate Design Wind Speeds determined from Figure 1609A in the Florida Building Code, Building or Figure R301.2(4) in the Florida Building Code, Residential.
708.8.1.1 Access for Retrofitting Roof to Wall Connections
These provisions are not intended to limit the means for gaining access to the structural elements of the roof and wall for the purposes of retrofitting the connection. The retrofit of roof to wall connections can be made by access through the area under the eave, from above through the roof, or from the interior of the house. Methods for above access include removal of roof panels or sections thereof or removal of portions of roof paneling at selected locations large enough for access, viewing, and installing the retrofit connectors and fasteners.
Where panels or sections are removed, the removed portions shall not be reused. New paneling shall be used and fastened as in new construction.
Holes shall be deemed adequately repaired if a patch of paneling is installed with no gap greater than 1/2 inch (13 mm) between the patch and the existing sheathing and if the patch is supported using one of the following methods.
- Solid 11/2-inch lumber shall fully support the patch and shall be secured to the existing sheathing with #8 by 11/4-inch screws spaced a minimum of 3 inches (76 mm) around the perimeter with screws a minimum of 3/4 inch (19 mm) from the near edge of the hole. The patch shall be secured to the lumber with #8 × 11/4-inch screws spaced on a grid no greater than 6 inches by 6 inches (152 mm × 152 mm) with no fewer than two screws.
- Holes that extend horizontally from roof framing member to adjacent roofing framing member that are less than or equal to 7 inches (178 mm) wide along the slope of the roof shall be supported by minimum of 2 × 4 lumber whose face is attached to each roofing framing members using a minimum of two each 3-inch (76 mm) long fasteners (#8 screws or 10d common nails) connecting the two. The patch shall have attached to its bottom, running horizontally, a minimum 2 × 4 either flat wise or on edge secured with #8 × 11/4-inch screws a maximum of 4-inches (102 mm) on center and no more distant from the end of the added lumber than 3 inches (76 mm). The patch shall be secured with two #8 × 11/4-inch screws to each support member.
708.8.1.2 Partially Inaccessible Straps
Where part of a strap is inaccessible, if the portion of the strap that is observed is fastened in compliance with these requirements, the inaccessible portion of the strap shall be presumed to comply with these requirements.
708.8.1.3 Prescriptive Method for Gable Roofs on a Wood Frame Wall
The anchorage of each of the exposed rafters or truss within 6 feet (1829 mm) of the corner along the exterior wall on each side of each gable end shall be inspected. Wherever a strap is missing or an existing strap has fewer than four fasteners on each end, approved straps, ties or right angle brackets with a minimum uplift capacity of 500 pounds (740 kg) shall be installed that connect each rafter or truss to the top plate below. Adding fasteners to existing straps shall be allowed in lieu of adding a new strap provided the strap is manufactured to accommodate at least four fasteners at each end. Wherever access makes it possible (without damage of the wall or soffit finishes), both top plate members shall be connected to the stud below using a stud to plate connector with a minimum uplift capacity of 500 pounds (740 kg). Use of straps that connect directly from the rafter or truss to the wall stud below shall be allowed as an alternate provided the two members align with no more than 11/2 inches (38 mm) offset.
708.8.1.4 Prescriptive Method for Gable Roofs on a Masonry Wall
The anchorage of each of the exposed rafters or truss within 6 feet (1829 mm) of the corner along the exterior wall on each side of each gable end shall be inspected. Wherever a strap is missing or an existing strap has fewer than four fasteners on each end, approved straps, ties or right angle gusset brackets with a minimum uplift capacity of 500 pounds (740 kg) shall be installed that connect each rafter or truss to the top plate below or directly to the masonry wall using approved masonry screws of a length and diameter recommended by the manufacturer. In the absence of manufacturer's recommendations, screws shall provide at least a 21/2-inch (64 mm) embedment into the concrete or masonry. When the straps or right angle gusset brackets are attached to a wood sill plate, the sill plate shall be anchored to the concrete masonry wall below. This anchorage shall be accomplished by installing 1/2 -inch diameter masonry screws, each with supplementary 1/4-inch washer, having sufficient length to develop a 21/2-inch (64 mm) embedment into the concrete and masonry. These screws shall be installed within 4 inches (102 mm) of the truss or rafter on both sides of each interior rafter or truss and on the accessible wall side of the gable end truss or rafter.
708.8.1.5 Prescriptive Method for Hip Roofs on a Wood Frame Wall
Unless it is possible to verify through nondestructive inspection or from plans prepared by a design professional that the roof structure is anchored at least as well as outlined below, access shall be provided at a minimum to the hip rafter (commonly known as a "king jack"), to the hip girder and at each corner of the hip roof. The hip rafter (commonly known as a "king jack"), the hip girder and the rafters/trusses adjacent to the hip girder that are not anchored with a strap having at least four fasteners on each end, shall be connected to the top plate below using a strap or a right angle gusset bracket having a minimum uplift capacity of 500 pounds (740 kg). Adding fasteners to existing straps shall be allowed in lieu of adding a new strap provided the strap is manufactured to accommodate at least 4 fasteners at each end. Wherever access makes it possible (without damage of the wall or soffit finishes), both top plate members shall be connected to the stud below using a stud to plate connector with a minimum uplift capacity of 500 pounds (740 kg). Use of straps that connect directly from the hip rafter, hip girder or adjacent rafters/trusses to the wall stud below shall be allowed as an alternate provided the two members align with no more than 11/2-inch (38 mm) offset.
708.8.1.6 Prescriptive Method for Hip Roofs on a Masonry Wall
Unless it is possible to verify through nondestructive inspection or from plans prepared by a design professional that the roof structure is anchored at least as well as outlined below, access shall be provided at a minimum to the hip rafter (commonly known as a "king jack"), to the hip girder and at each corner of the hip roof. The hip rafter (commonly known as a "king jack"), the hip girder and the rafters/trusses adjacent to the hip girder that are not anchored with a strap having at least four fasteners on each end, shall be connected to the concrete masonry wall below using approved straps or right angle gusset brackets with a minimum uplift capacity of 500 pounds (740 kg). Adding fasteners to existing straps shall be allowed in lieu of adding a new strap provided the strap is manufactured to accommodate at least 4 fasteners at each end. The straps or right angle gusset brackets shall be installed such that they connect each rafter or truss to the top plate below or directly to the masonry wall using approved masonry screws of a length and diameter recommended by the manufacturer. In the absence of manufacturer's recommendations, screws shall provide at least 21/2-inches (64 mm) embedment into the concrete or masonry. When the straps or right angle gusset brackets are attached to a wood sill plate, the sill plate shall be anchored to the concrete masonry wall below. This anchorage shall be accomplished by installing 1/4-inch (6 mm) diameter masonry screws, each with supplementary 1/4-inch (6 mm) washer, with sufficient length to develop a 21/2-inch (64 mm) embedment into the concrete and masonry. These screws shall be installed within 4 inches (102 mm) of the truss or rafter on both sides of each interior rafter or truss and on the accessible wall side of the gable end truss or rafter.
708.8.1.7 Priorities for Mandated Roof-to-Wall Retrofit Expenditures
Priority shall be given to connecting the exterior corners of roofs to walls where the spans of the roofing members are greatest. For houses with both hip and gable roof ends, the priority shall be to retrofit the gable end roof-to-wall connections unless the width of the hip end is more than 1.5 times greater than the width of the gable end. When considering priorities for houses with both hip and gable roof ends, and the fifteen percent of the cost of roof replacement is sufficient to complete all of the prioritized elements pursuant to this section, but is not sufficient to complete all of the nonprioritized elements, then no portion of complete retrofit of the nonprioritized element is required.
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