Materials and methods of application used for recovering or replacing an existing roof covering shall comply with the requirements of Chapter 15 of the Florida Building Code, Building, or Chapter 9 of the Florida Building Code, Residential. Roof repairs to existing roofs and roof coverings shall comply with the provisions of this code.
Exception: Reroofing shall not be required to meet the minimum design slope requirement of one-quarter unit vertical in 12 units horizontal (2-percent slope) in Section 1507 of the Florida Building Code, Building for roofs that provide positive roof drainage (High-Velocity Hurricane Zones shall comply with Sections 1515.2.2.1 and 1516.2.4 of the Florida Building Code, Building).
New roof coverings shall not be installed without first removing all existing layers of roof coverings down to the roof deck where any of the following conditions occur:
- Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
- Where the existing roof covering is wood shake, slate, clay, cement or asbestos-cement tile.
- Where the existing roof has two or more applications of any type of roof covering.
- When blisters exist in any roofing, unless blisters are cut or scraped open and remaining materials secured down before applying additional roofing.
- Where the existing roof is to be used for attachment for a new roof system and compliance with the securement provisions of Section 1504.1 of the Florida Building Code, Building cannot be met.
Exceptions:
- Building and structures located within the High-Velocity Hurricane Zone shall comply with the provisions of Sections 1512 through 1525 of the Florida Building Code, Building.
- Complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building’s structural system and that do not rely on existing roofs and roof coverings for support, shall not require the removal of existing roof coverings.
- Reserved.
- The application of a new protective coating over an existing spray polyurethane foam roofing system shall be permitted without tear-off of existing roof coverings.
- Roof Coating. Application of elastomeric and or maintenance coating systems over existing asphalt shingles shall be in accordance with the shingle manufacturer’s approved installation instructions.
When a roof covering on an existing sitebuilt single-family residential structure is removed and replaced, the following procedures shall be permitted to be performed by the roofing contractor:
- Roof-decking attachment shall be as required by Section 706.7.1.
- A secondary water barrier shall be provided as required by Section 706.7.2.
Exception: Single-family residential structures permitted subject to the Florida Building Code are not required to comply with this section.
For roof decking consisting of wood structural panels, fasteners and spacing required in columns 3 and 4 of Table 706.7.1.2 are deemed to comply with the requirements of Section 707.3, Florida Building Code, Existing Building for the indicated design wind speed range. Wood structural panel connections retrofitted with a two part urethane based closed cell adhesive sprayed onto the joint between the sheathing and framing members are deemed to comply with the requirements of Section 707.3, Florida Building Code, Existing Building, provided testing using the manufacturer’s recommended application on panels connected with 6d smooth shank nails at no more than a 6-inch edge and 12-inch field spacing demonstrate an uplift resistance of a minimum of 200 psf.
Supplemental fasteners as required by Table 706.7.1.2 shall be ASTM F1667 classification RSRS-01 ring shank nails with the following minimum dimensions:
- 0.113-inch nominal shank diameter.
- Ring diameter a minimum of 0.010 inch over shank diameter.
- 16 to 20 rings per inch.
- A minimum 0.280-inch full round head diameter.
- Ring shank to extend a minimum of 11/2 inches from the tip of the nail.
- Minimum 23/8 inches nail length.
SUPPLEMENT FASTENERS AT PANEL EDGES AND INTERMEDIATE FRAMING
| EXISTING FASTENERS | EXISTING SPACING | Vasdc 110 MPH OR LESS SUPPLEMENTAL FASTENER SPACING SHALL BE NO GREATER THAN | Vasdc GREATER THAN 110 MPH SUPPLEMENTAL FASTENER SPACING SHALL BE NO GREATER THAN |
| Staples or 6d | Any | 6″ o.c.b | 6″ o.c.b |
| 8d clipped head, round head, smooth or ring shank | 6″ o.c. or less | None necessary | None necessary |
| 8d clipped head, round head, smooth or ring shank | Greater than 6″ o.c. | 6″ o.c.a | 6″ o.c.a |
For SI: 1 inch = 25.4 mm.
- Maximum spacing determined based on existing fasteners and supplemental fasteners.
- Maximum spacing determined based on supplemental fasteners only.
- Vasd shall be determined in accordance with Section 1609.3.1 of the Florida Building Code, Building or Section R301.2.1.3 of the Florida Building Code, Residential.
A secondary water barrier shall be installed using one of the following methods when roof covering is removed and replaced:
In High-Velocity Hurricane Zone regions:
- All joints in structural panel roof sheathing or decking shall be covered with a minimum 4 inch (102 mm) wide strip of self-adhering polymer modified bitumen tape applied directly to the sheathing or decking. The deck and self-adhering polymer modified bitumen tape shall be covered with one of the underlayment systems approved for the particular roof covering to be applied to the roof.
- The entire roof deck shall be covered with an approved asphalt impregnated 30# felt underlayment or approved synthetic underlayment installed with nails and tin-tabs in accordance with Section 1518.2, 1518.3 or 1518.4 of the Florida Building Code, Building. (No additional underlayment shall be required over the top of this sheet.) The synthetic underlayment shall be fastened in accordance with the manufacturer’s recommendations.
Outside the High-Velocity Hurricane Zone:
- Underlayment shall comply with Section R905.1.1 of the Florida Building Code, Residential.
Exceptions:
- Roof slopes < 2:12 having a continuous roof system shall be deemed to comply with Section 706.7.2 requirements for a secondary water barrier.
- Clay and concrete tile roof systems installed as required by the Florida Building Code are deemed to comply with the requirements of Section 706.7.2 for Secondary Water Barriers.
When a roof covering on an existing site-built singlefamily residential structure is removed and replaced on a building that is located in the wind-borne debris region as defined in the Florida Building Code, Building and that has an insured value of $300,000 or more or, if the building is uninsured or for which documentation of insured value is not presented, has a just valuation for the structure for purposes of ad valorem taxation of $300,000 or more:
- Roof to wall connections shall be improved as required by Section 706.8.1.
- Mandated retrofits of the roof-to-wall connection shall not be required beyond a 15 percent increase in the cost of reroofing.
Exception: Single-family residential structures permitted subject to the Florida Building Code are not required to comply with this section.
Where required by Section 706.8, the intersection of roof framing with the wall below shall provide sufficient resistance to meet the uplift loads specified in Table 706.8.1 either because of existing conditions or through retrofit measures. As an alternative to an engineered design, the prescriptive retrofit solutions provided in Sections 706.8.1.1 through 706.8.1.7 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-tofoundation 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.
REQUIRED UPLIFT CAPACITIES FOR ROOF-TO-WALL CONNECTIONSa, b (POUNDS PER LINEAR FOOT)
| ULTIMATE DESIGN WINDSPEED, Vultc,d | 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 R301.2.1.1 of the Florida Building Code, Residential or ASCE 7.
- Ultimate Design Wind Speeds determined from Figure 1609.3(1) in the Florida Building Code, Building or Figure R301.2(4) in the Florida Building Code, Residential.
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 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 2 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 a minimum of 2 × 4 lumber whose face is attached to each roofing framing members using a minimum of 2 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.