The new Florida Building Code Eighth Edition (2023) went into effect December 31, 2023. There are numerous changes that have a significant impact on the roofing industry. FRSA has been deeply involved in its development during the three-year modification and promulgation cycle. We have developed educational information that previews these changes based on knowledge gained during the cycle and on the published code supplements. Most of this was done before the final draft of the code was available. We submitted these seminars for approval for continuing education credit and presented seminar overviews at the majority of our local affiliates that covered most of the important changes. We presented the seminars several times at our Convention in July last year as well as several times at the FRSA Training Center. We partnered with the Building Officials of Florida (BOAF) to present them at six locations throughout Florida for both contractors and building officials.
I have covered many of these changes in my Florida Roofing articles during and after the code modification process. Hopefully, you have been able to get up to date through these efforts. If not, we will be offering many updated and advanced courses at the Convention in June.
I understand that devoting the time to familiarize yourself with building code changes may not be your highest priority but having someone in your organization that has is critical. Since the code has been implemented and must be complied with, I will attempt to provide you with information in this article that will answer some of your questions. It is quite an extensive but not an all-inclusive review. We will be reviewing specific sections of the code. At the beginning of each code section there is a title that addresses which version, volume or sub-code, chapter and section of the code where the language appears. You can do a more thorough analysis by reviewing the applicable code section.
The new code changes are in blue and underlined; code language that has been removed is shown in red and stricken through. If I want to emphasize something, it will be in underlined while text that is bold appears that way in the code. Questions to be addressed appear in bold green and any notes I provide that are not in the code appear in red. I am available to FRSA members to answer your code-related questions.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, RESIDENTIAL
CHAPTER 3 – BUILDING PLANNING
SECTION 301 DESIGN
FIGURE R301.2(4) ULTIMATE DESIGN WIND SPEEDS, Vult
Note: Maps shown are new. The red circle indicates the areas where wind speeds have changed substantially.
The Residential Code Figure R301.2.(4) (below) shows the wind contour lines and also shows the wind-borne debris region (shaded) on a single map. The Building Code has four different contour maps and the wind-borne debris region is described in definitions Chapter 2. The wind-borne debris region will change depending on the risk category (type of occupancy) for the building. The residential map is basically the same as for Risk Category II structure in the Building Code volume. This is the most common risk category for buildings.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING AND RESIDENTIAL
CHAPTER 2 – DEFINITIONS
WIND-BORNE DEBRIS REGION. Areas within hurricane-prone regions located:
Within 1 mile (1.61 km) of the mean high-water line where an Exposure D condition exists upwind at the waterline and the ultimate design wind speed, Vult, is 130 mph (58 m/s) or greater; or
In areas where the ultimate design wind speed, Vult, is 140 mph (63.6 m/s) or greater.
For Risk Category II buildings and other structures and Risk Category III buildings and other structures, except health care facilities, the wind-borne debris region shall be based on Figure 1609.3(1). For Risk Category III health care facilities, the wind-borne debris region shall be based on Figure 1609.3(2). For Risk Category IV buildings and other structures, the wind-borne debris region shall be based on Figure 1609.3(3).
The need to know the wind speeds to attain the ASCE 7 uplift resistance requirements should be obvious. Less obvious is that the Existing Building Code uses wind-borne debris regions as one trigger for when roof-to-wall connections may need to be addressed. Knowing if a reroof project that meets the other mitigation criteria is located in the wind-borne debris region is also clearly important.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, EXISTING BUILDING
CHAPTER 7 – ALTERATIONS – LEVEL 1, SECTION 706 EXISTING ROOFING
Note: Reroofing is an Alteration Level 1
706.8 When a roof covering on an existing structure with a sawn lumber, wood plank or wood structural panel roof deck 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:
(a) Roof to wall connections shall be improved as required by Section 706.8.1.
(b) Mandated retrofits of the roof-to-wall connection shall not be required beyond a 15 percent increase in the cost of reroofing.
Exception: Structures permitted subject to the Florida Building Code are not required to comply with this section.
706.8.1 Roof-to-wall connections for structures with wood roof decks. 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-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.
ASCE is the acronym for the American Society of Civil Engineers who produce the Minimum Design Loads and Associated Criteria for Buildings and other Structures (ASCE/SEI 7) and is a reference standard in the code, which makes it part of the code. To help you appreciate how a change in ASCE 7 can impact the code, changing from ASCE 7-16 to ASCE 7-22 affected 125 different code sections. We will look at several of these changes but won’t review all of them here.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1504 PERFORMANCE REQUIREMENTS
1504.1 Wind resistance of roofs.
Roof decks and roof coverings shall be designed for wind loads in accordance with Chapter 16 and Sections 1504.2, 1504.3 and 1504.4.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING
CHAPTER 16 – STRUCTURAL DESIGN
SECTION 1609 WIND LOADS
1609.1 Applications. Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures. All exterior wall coverings and soffits shall be capable of resisting the design pressures specified for walls for components and cladding loads in accordance with Section 1609.1.1. Manufactured soffits shall be labeled in accordance with Section 1709.10 of this code.
1609.1.1 Determination of wind loads. Wind loads on every building or structure shall be determined in accordance with Chapters 26 to 30 of ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.
The wind speeds in Figures 1609.3(1), 1609.3(2), 1609.3(3) and 1609.3(4) are ultimate design wind speeds, Vult, and shall be converted in accordance with Section 1609.3.1 to nominal design wind speeds, Vasd, when the provisions of the standards referenced in Exceptions 4 and 5 are used.
The Building Code volume refers to ASCE 7 in many locations but it doesn’t include the drawings showing the cladding (roof covering) pressure zones. The drawings shown on the next page are included in the Residential Code and reflect those contained in the ASCE 7 standard. A major difference is the size of the zones (a). In Residential it is always four feet. In Building it must be calculated based on the building height and size. You will notice that we have returned to three different zones (1, 2, 3) in ASCE 7-22 However, the specific locations of the zones have changed significantly and need to be understood. Alternately, you may use the highest pressures in all of the zones. The actual uplift pressures have not changed drastically between ASCE 7-16 and ASCE 7-22, but they are different.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, RESIDENTIAL
CHAPTER 3 – BUILDING PLANNING
SECTION 301 DESIGN CRITERIA
FIGURE R301.2(7) COMPONENT CLADDING PRESSURE ZONES
Some changes were made by the legislature in the statute mid-code cycle and were effective immediately. Other changes were made through the normal code modification process.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, RESIDENTIAL, EXISTING BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
CHAPTER 9 – ROOF ASSEMBLIES
CHAPTER 7 – ALTERATIONS – LEVEL 1
The “25 % Rule”
SECTIONS 1511.1.1 and 1521.4 (R908.1.1) (EB706.1.1) Not more than 25 percent of the total roof area or roof section of any existing building or structure shall be repaired, replaced or recovered in any 12-month period unless the roof covering on the entire existing roofing system or roof section is replaced or recovered to conform to the requirements of this code.
Exception: If an existing roofing system or roof section was built, repaired, or replaced in compliance with the requirements of the 2007 Florida Building Code, or any subsequent editions of the Florida Building Code, and 25 percent or more of such roofing system or roof section is being repaired, replaced, or recovered, only the repaired, replaced, or recovered portion is required to be constructed in accordance with the Florida Building Code in effect, as applicable. Pursuant to s. 553.844(5), Florida Statutes, a local government may not adopt by ordinance an administrative or technical amendment to this exception.
Most of these base code changes are very similar to the HVHZ requirements but, as recommended, those who work in the HVHZ should understand the differences. One major change in the HVHZ is the acceptance of approved self-adhering underlayment installed direct to deck for all steep-slope (>2:12) roof systems.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, RESIDENTIAL AND EXISTING BUILDING
CHAPTER 9 – ROOF ASSEMBLIES
CHAPTER 7 – ALTERATIONS – LEVEL 1
SECTIONS R908 AND EB706 EXISTING ROOFING
R908.7.2 Roof secondary water barrier for existing structures with wood roof decks.
Note: Separate HVHZ region requirements were removed.
When a roof covering is removed and replaced, a secondary water barrier shall be installed in accordance with Section R905.1.1 or Section 1518.2 of the Florida Building Code, Building.
Exceptions:
Roof slopes < 2:12 having a continuous roof system shall be deemed to comply with Section R908.7.2 requirements for a secondary water barrier.
Clay and concrete tile roof systems installed as required by the Florida Building Code, Residential are deemed to comply with the requirements of Section R908.7.2 for Secondary Water Barriers.
706.7.2 Roof secondary water barrier for existing structures with wood roof decks.
Note: Separate HVHZ region requirements were removed.
When a roof covering is removed and replaced, a secondary water barrier shall be installed in accordance with Section 1507.1.1 or 1518.2 of the Florida Building Code, Building or 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.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING AND RESIDENTIAL
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
CHAPTER 9 – ROOF ASSEMBLIES
SECTIONS 1507 AND R905 REQUIREMENTS FOR ROOF COVERINGS
1507.1.1 (R905.1.1) Underlayment. Underlayment for roof slopes 2:12 and greater shall conform to the applicable standards listed in this chapter. Underlayment materials required to comply with ASTM D226, D1970, D4869, D6757 and ASTM D8257 shall bear a label indicating compliance to the standard designation and, if applicable, type classification indicated. Underlayment for roof slopes 2:12 and greater shall be applied and attached in accordance with Section 1507.1.1.1, (R905.1.1.1) or 1507.1.1.2 (R905.1.1.2) as applicable.
Exceptions:
For areas of a roof that cover exterior walkways and roofs of agricultural buildings, underlayment shall comply with the manufacturer’s installation instructions.
Compliance with Section 1507.1.1.1 is not required for structural metal panels that do not require a substrate or underlayment.
1507.1.1.1 (R905.1.1.1) Underlayment for asphalt shingles, metal roof panels or shingles, mineral surfaced roll roofing, slate and slate-type shingles, wood shakes, wood shingles.
Underlayment for asphalt shingles, metal roof panels or shingles, mineral surfaced roll roofing, slate and slate-type shingles, wood shakes, wood shingles shall comply with one of the following methods:
The entire roof deck shall be covered with an approved self-adhering polymer modified bitumen underlayment complying with ASTM D1970 installed in accordance with both the underlayment manufacturer’s and roof covering manufacturer’s installation instructions for the deck material, roof ventilation configuration and climate exposure for the roof covering to be installed.
Exceptions:
This method is not permitted for wood shingles or shakes.
An existing self-adhering modified bitumen underlayment that has been previously installed over the roof decking and, where it is required, renailing of the roof sheathing in accordance with Section 706.7.1 of the Florida Building Code, Existing Building can be confirmed or verified. An approved underlayment in accordance with Table 1507.1.1.1 for the applicable roof covering shall be applied over the entire roof over the existing self-adhered modified bitumen underlayment.
2. A minimum 3-3/4-inch-wide (96 mm) strip of self-adhering polymer-modified bitumen membrane complying with ASTM D1970 or self-adhering flexible flashing tape complying with AAMA 711, Level 3 [for exposure up to 176°F (80°C)], installed in accordance with the manufacturer’s instructions for the deck material, shall be applied over all joints in the roof decking. An approved underlayment in accordance with Table 1507.1.1.1 for the applicable roof covering shall be applied over the entire roof over the membrane strips.
Two layers of ASTM D226 Type II or ASTM D4869 Type III, Type IV, or ASTM D8257 underlayment shall be installed as follows: Apply a strip of underlayment for the first course that is half the width of a full sheet parallel to and starting at the eaves, fastened sufficiently to hold in place. Starting at the eave, apply a full sheet of reinforced underlayment, for the second course. Apply the third course of underlayment overlapping the second course successive sheets half the width of a full sheet plus 2 inches. Overlap all successive courses half the width of a full sheet plus 1 inch. End laps shall be 6 inches (152 mm) and shall be offset by 6 feet (1829 mm). Underlayment shall be attached to a nailable deck with corrosion-resistant fasteners with a maximum fastener spacing measured horizontally and vertically of 12 inches (305 mm) o.c. between side laps, and one row at the end and side laps fastened 6 inches (152 mm) o.c. Underlayment shall be attached using annular ring or deformed shank nails with metal or plastic caps with a nominal cap diameter of not less than 1 inch (25.4 mm). Metal caps are required where the ultimate design wind speed, Vult, equals or exceeds 170 mph. Metal caps shall have a thickness of not less than 32-gage sheet metal. The minimum thickness of the outside edge of plastic caps shall be 0.035 inch (0.889 mm). The cap nail shank shall be not less than 0.083 inch (2.1082 mm) for ring shank cap nails. The cap nail shank shall have a length sufficient to penetrate through the roof sheathing or not less than 3/4 inch (19.05 mm) into the roof sheathing.
Exception:
Use of ASTM D8257 underlayment is not permitted for wood shingles or shakes.
The following sections are from the installation of asphalt shingle descriptions but apply as much to the underlayment as they do to the installation of the actual shingles or flashing. There are significant changes to how the underlayment and the drip edge interface. Please review these sections and the diagram thoroughly if you install asphalt shingles.
R905.2.4.1 Installation of asphalt shingles. Asphalt shingles shall be installed in accordance with Sections R905.2.6 and R905.2.6.1.
1507.2 Asphalt shingles. The installation of asphalt shingles shall comply with the provisions of this section, or RAS 115.
1507.2.1 Deck requirements. Asphalt shingles shall be fastened to solidly sheathed decks.
1507.2.2 Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (17- percent slope) or greater.
1507.2.3 Underlayment. Underlayment shall comply and be installed in accordance with Section 1507.1.1.
1507.2.9.3 (R905.2.8.5) Drip edge. Provide drip edge at eaves and gables of shingle roofs. Overlap is to be a minimum of 3 inches (76 mm). Eave drip edges shall extend 1/2 inch (13 mm) below sheathing and extend back on the roof a minimum of 2 inches (51 mm). Drip edge at gables shall be installed over the underlayment. Drip edge at eaves be permitted to be installed either over or under the underlayment. If installed over the underlayment. Self-adhering, ASTM D1970 underlayment may be installed over a primed drip edge flange (see figure on page 22).
There shall be a minimum 4 inches (51 mm) width of roof cement installed over the drip edge flange or the self-adhering underlayment. Drip edge shall be mechanically fastened a maximum of 12 inches (305 mm) on center. Where the Vasd as determined in accordance with Section 1609.3.1, is 110 mph (177 km/h) or greater or the mean roof height exceeds 33 feet (10,058 mm), drip edges shall be mechanically fastened a maximum of 4 inches (102 mm) on center (see below).
Most of the changes to tile underlayment installations outside the HVHZ are covered in the FRSA-TRI Florida High Wind Concrete and Clay Roof Tile Installation Manual, Seventh Edition. The major change in the underlayment section is due to the industries’ desire to have all tile underlayments tested for resistance to wind uplift as described in section 1504.2.1.4 Underlayment testing (see next page). This approach is in compliance with ASCE 7 and has eliminated the prescriptive two-ply hot mop option with the enhanced nailing per the old Table 1 in the Sixth Edition of the tile manual. This type of system may still be used but only with the proper testing as reflected in a current product approval. Again, some sections are not in numerical order to emphasize the underlayment changes. In the HVHZ, it appears a similar testing approach with self-adhering (peel and stick) underlayments will also be used. However, there is one major difference: two-ply hot mop systems will be allowed using prescriptive methods that do not include the enhanced fastening patterns in the manual. This circumvents the underlayment testing that is now required for all tile underlayment throughout Florida. As mentioned earlier, one major change in the HVHZ is the acceptance of approved self-adhering underlayment installed direct to deck for all steep-slope (2:12) roof systems.
1507.1.1.2 Underlayment for concrete and clay tile.
Underlayment for concrete and clay tile shall comply with Section 1507.3.3 (R905.3.3)
1507.3 (R905.3) Clay and concrete tile.
1507.3.3 Underlayment (compare to R905.3.3).
Unless otherwise noted, underlayment shall be applied according to the underlayment manufacturer’s installation instructions or the recommendations of the FRSA-TRI Florida High Wind Concrete and Clay Roof Tile Installation Manual, Seventh Edition where the basic wind speed, Vasd, is determined in accordance with Section 1609.3.1 (R301.2.1.3) or the recommendations of RAS 118, 119 or 120.
Exception: Where an existing self-adhering modified bitumen underlayment that has been previously installed over the roof decking and, where it is required, renailing of the roof sheathing in accordance with Section 706.7.1 of the Florida Building Code, Existing Building can be confirmed or verified. An approved underlayment in accordance with a two-ply system as described in the FRSA-TRI Florida High Wind Concrete and Clay Roof Tile Installation Manual, Seventh Edition shall be applied over the entire roof over the existing self-adhered modified bitumen underlayment.
1507.3.3.1 Slope and underlayment requirements (compare to R905.3.3.1). Refer to FRSA-TRI Florida High Wind Concrete and Clay Roof Tile Installation Manual, Seventh Edition where the basic wind speed Vasd is determined in accordance with Section 1609.3.1 (R301.2.1.3) for underlayment and slope requirements for specific roof tile systems. or the recommendations of RAS 111, 118, 119 or 120.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1504 PERFORMANCE REQUIREMENTS
1504.2.1 Testing. Testing of concrete and clay tile roof coverings shall be in accordance with Sections 1504.2.1.1, 1504.2.1.2, and 1504.2.1.3. Testing of underlayment or underlayment assembly for clay and concrete tile roof coverings shall be in accordance with Section 1504.2.1.4.
1504.2.1.1. Overturning resistance. Concrete and clay roof tiles shall be tested to determine their resistance to overturning due to wind in accordance with SBCCI SSTD 11 and Chapter 15.
1504.2.1.2 Wind tunnel testing. Where concrete and clay roof tiles do not satisfy the limitations in Chapter 16 for rigid tile, a wind tunnel test shall be used to determine the wind characteristics of the concrete or clay tile roof covering in accordance with Chapter 15 and either SBCCI SSTD 11 or ASTM C1569.
1504.2.1.4 Air permeability testing. The lift coefficient for concrete and clay tile shall be 0.2 or shall be determined in accordance with SBCCI SSTD 11 or ASTM C1570.
1504.2.1.4 Underlayment testing. Adhered or mechanically attached tile underlayment or underlayment assemblies shall be tested in accordance with FM 4474 or UL 1897.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING AND RESIDENTIAL
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
CHAPTER 9 – ROOF ASSEMBLIES
SECTIONS 1507 AND R905 REQUIREMENTS FOR ROOF COVERINGS
1507.2.2 (R905.2.2) Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (17 percent slope) or greater.
1507.2.4 RESERVED.
R905.2.4.1 Installation of asphalt shingles. Asphalt shingles shall be installed in accordance with Sections R905.2.6 and R905.2.6.1.
1507.2.5 Asphalt shingles. Asphalt shingles shall have self-seal strips or be interlocking and comply with ASTM D3462.
1507.2.7 Attachment. Asphalt shingles shall have the minimum number of fasteners required by the manufacturer and Section 1504.1. Asphalt shingles shall be secured to the roof with not less than four fasteners per strip shingle or two fasteners per individual shingle. Where the roof slope exceeds 21 units vertical in 12 units horizontal (21:12), asphalt shingles shall be installed in accordance with the manufacturer’s printed installation instructions for steep-slope roof applications.
1507.2.7.1 Wind resistance of asphalt shingles. Asphalt shingles shall be tested and classified in accordance with ASTM D3161, ASTM D7158 or TAS 107 and shall meet the required classification in accordance with Table 1507.2.7.1 to resist the applicable wind speed per Figure 1609.3(1), 1609.3(2), 1609.3(3), or 1609.3(4) based on the Risk Category. Asphalt shingle wrappers shall be labeled to indicate compliance with one of the required classifications, as shown in Table 1507.2.7.1. (R905.2.4.1) (see below).
1507.2.9 Flashings. Flashing for asphalt shingles shall comply with this section or RAS 111. Flashing shall be applied in accordance with this section, the asphalt shingle manufacturer’s printed instructions or RAS 111.
R905.2.8 Flashings. Flashing for asphalt shingles shall comply with this section or RAS 111.
1507.2.9.2 Valleys (compare to R905.2.8.2). Valley linings shall be installed in accordance with the manufacturer’s instructions before applying shingles. Valley linings of the following types shall be permitted:
For open valleys (valley lining exposed) lined with metal, the valley lining shall be at least 16 inches (406 mm) wide and of any of the corrosion-
resistant metals in Table 1503.2.
For open valleys, valley lining of two plies of mineral-surfaced roll roofing complying with ASTM D3909, or ASTM D6380 Class M shall be permitted. The bottom layer shall be 18 inches (457 mm) and the top layer a minimum of 36 inches (914 mm) wide.
For closed valleys (valleys covered with shingles), valley lining of one ply of smooth roll roofing complying with ASTM D6380 Class S, and at least 36 inches (914 mm) wide or types as described in Item 1 or 2 above shall be permitted. Self-adhering polymer modified bitumen underlayment complying with ASTM D1970 and not less than 36 inches (914 mm) wide shall be permitted in lieu of the lining material.
1507.2.9.3 (R905.2.8.5) Drip edge. Provide drip edge at eaves and gables of shingle roofs. Overlap is to be a minimum of 3 inches (76 mm). Eave drip edges shall extend 1/2 inch (13 mm) below sheathing and extend back on the roof a minimum of 2 inches (51 mm). Drip edge at gables shall be installed over the underlayment. Drip edge at eaves be permitted to be installed either over or under the underlayment. If installed over the underlayment. Self-adhering, ASTM D1970 underlayment may be installed over a primed drip edge flange. There shall be a minimum 4 inches (51 mm) width of roof cement installed over the drip edge flange or the self-adhering underlayment. Drip edge shall be mechanically fastened a maximum of 12 inches (305 mm) on center. Where the Vasd as determined in accordance with Section 1609.3.1, is 110 mph (177 km/h) or greater or the mean roof height exceeds 33 feet (10,058 mm), drip edges shall be mechanically fastened a maximum of 4 inches (102 mm) on center.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, ENERGY CONSERVATION
CHAPTER 3 – GENERAL REQUIREMENTS
SECTION C303 MATERIALS, SYSTEMS AND EQUIPMENT
C303.1.5 Roof solar reflectance and thermal emittance. Low-sloped roofs directly above cooled conditioned spaces in Climate Zones 1a shall comply with one or more of the options in Table C402.3.
Climate Zone 1A
A type of climate defined in the ASHRAE 169-2006 standard consisting of Climate Zone Number 1 and Climate Zone Subtype A.
Climate Zone 1A is defined as Very Hot – Humid with IP Units 9000 < CDD50ºF and SI Units 5000 < CDD10ºC.
ANSI/CRRC-S100 - 20162020 Standard Test Methods for Determining Radiative Properties of Materials
The following places are categorized as class 1A climate zones:
Broward County, Florida: Energy Resources
Hawaii County, Hawaii: Energy Resources
Honolulu County, Hawaii: Energy Resources
Kalawao County, Hawaii: Energy Resources
Kauai County, Hawaii: Energy Resources
Maui County, Hawaii: Energy Resources
Miami-Dade County, Florida: Energy Resources
Monroe County, Florida: Energy Resources
Miami is the representative city for Climate Zone 1A used in the DOE Commercial Reference.
CHAPTER 4 – COMMERCIAL ENERGY EFFICIENCY
SECTION C402 BUILDING ENVELOPE REQUIREMENTS
C402.3 Roof solar reflectance and thermal emittance.
Low-sloped roofs directly above cooled conditioned spaces in Climate Zones 1, 2 and 3 shall comply with one or more of the options in Table C402.3.
Exceptions: The following roofs and portions of roofs are exempt from the requirements of Table C402.3:
1. Portions of the roof that include or are covered by the following:
1.1. Photovoltaic systems or components.
1.2. Solar air or water-heating systems or components.
1.3. Roof gardens or landscaped roofs.
1.4. Above-roof decks or walkways.
1.5. Skylights.
1.6. HVAC systems and components, and other opaque objects mounted above the roof.
2. Portions of the roof shaded during the peak sun angle on the summer solstice by permanent features of the building or by permanent features of adjacent buildings.
3. Portions of roofs that are ballasted with a minimum stone ballast of 17 pounds per square foot [74 kg/m2] or 23 psf [117 kg/m2] pavers.
4. Roofs where not less than 75 percent of the roof area complies with one or more of the exceptions to this section.
TABLE C402.3 Notes
a. The use of area-weighted averages to comply with these requirements shall be permitted. Materials lacking 3-year-aged tested values for either solar reflectance or thermal emittance shall be assigned both a 3-year-aged solar reflectance in accordance with Section C402.3.1 and a 3-year-aged thermal emittance of 0.90.
b. Aged solar reflectance tested in accordance with ASTM C1549, ASTM E903 or ASTM E1918 or CRRC-1 Standard.
c. Aged thermal emittance tested in accordance with ASTM C1371 or ASTM E408 or CRRC-1 Standard.
d. Solar reflectance index (SRI) shall be determined in accordance with ASTM E1980 using a convection coefficient of 2.1 Btu/h · ft2 ·°F (12W/m2 · K). Calculation of aged SRI shall be based on aged tested values of solar reflectance and thermal emittance.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1504 PERFORMANCE REQUIREMENTS
1504.4 Ballasted low-slope single-ply roof systems. Ballasted low-slope (roof slope < 2:12) single-ply roof system coverings installed in accordance with Sections 1507.12 and 1507.13 shall be designed in accordance with ANSI/SPRI RP-4.
1504.5 Edge securement systems for low-slope roofs. Low-slope Metal edge systems, except gutters and counterflashing, installed on built-up, modified bitumen and single-ply roof systems having a slope less than 2:12, shall be designed and installed for wind loads in accordance with Chapter 16 and tested for resistance in accordance with Test Methods RE-1, RE-2 and RE-3 of ANSI/SPRI ES-1, or RAS 111 except Vult wind speed shall be determined from Figure 1609.3(1), 1609.3(2), 1609.3(3) or 1609.3(4) as applicable.
1504.5.1 Gutter securement for low-slope roofs. Gutters that are used to secure the perimeter edge of the roof membrane on low-slope (less than 2:12 slope) built-up, modified bitumen, and single ply roofs, shall be designed, constructed and installed to resist wind loads in accordance with Section 1609 and shall be tested in accordance with Test Methods G-1 and G-2 of SPRI GT-1.
2023 FLORIDA BUILDING CODE EIGHTH EDITION, BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1507 REQUIREMENTS FOR ROOF COVERINGS
1507.12 Thermoset single-ply Single-ply roofing.
The installation of thermoset single-ply roofing shall comply with the provisions of this section.
1507.12.1 Slope. Thermoset single-ply Single-ply membrane roofs shall have a design slope of not less than one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
1507.12.2 Material standards. Thermoset single-ply Single-ply roof coverings shall comply with ASTM D4637 or ASTM D5019 the material standards in Table 1507.12.2 (see next page).
1507.15 Liquid-applied roofing. The installation of liquid-applied roofing shall comply with the provisions of this section.
1507.15.1 Slope. Liquid-applied roofing shall have a design slope of not less than one-fourth unit vertical in 12 units horizontal (2 percent slope).
1507.15.2 Material standards. Liquid-applied roofing shall comply with ASTM C836, ASTM C957, ASTM D1227 or ASTM D3468
1507.15.3 Application. Liquid-applied roofing shall be installed in accordance with the approved manufacturer’s installation instructions.
1507.15.4 Flashings. Flashing shall be applied in accordance with 1507.15 and the liquid-applied roofing manufacturer’s installation instructions.
2023 FLORIDA BUILDING CODE EIGHTH EDITION RESIDENTIAL AND BUILDING
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
CHAPTER 9 – ROOF ASSEMBLIES
SECTIONS 1508 AND R906 ROOF INSULATION
1508.1 General. The use of above-deck thermal insulation shall be permitted provided that such insulation is covered with an approved roof covering and passes the tests of NFPA 276 or UL 1256 when tested as an assembly.
Exceptions:
Foam plastic roof insulation shall conform to the material and installation requirements of Chapter 26.
Where a concrete or composite metal and concrete roof deck is used, and the above-deck thermal insulation is covered with an approved roof covering.
SECTION R906 ROOF INSULATION
R906.1 General. Where above-deck thermal insulation is installed, such insulation shall be covered with an approved roof covering and shall comply with NFPA 276 or UL 1256.
2023 FLORIDA BUILDING CODE EIGHTH EDITION
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1509 ROOF COATINGS
1509.1 General. The installation of a roof coating on a roof covering shall comply with the requirements of Section 1505 and this section.
1509.2 Material standards. Roof coating materials shall comply with the standards in Table 1509.2.
Yes. One such change deals with concealed lines, pipes, conduit and cables. Another major change is the requirements for mandatory structural inspections for consistency with SB 4D (Surfside collapse, pictured right).
2023 FLORIDA BUILDING CODE EIGHTH EDITION
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
SECTION 1510 ROOFTOP STRUCTURES
1510.11 Cable- and raceway-type wiring methods. Cable- and raceway-type wiring methods installed on rooftops and not encased in structural concrete shall be supported above the roof system and covering. Cable- and raceway-type wiring methods installed in locations under metal-corrugated sheet roof decking shall be supported so there is not less than 38 mm (1-1/2 in.) measured from the lowest surface of the roof decking to the top of the cable or raceway. A cable or raceway shall not be installed in concealed locations in metal-corrugated sheet decking–type roof.
1510.12 Lines, pipes, conduit and cables under roof decks. Lines, pipes, conduit and cables installed below the roof deck shall have a minimum clearance of 1-1/2” from the lowest surface of the roof deck except where they penetrate the roof deck.
Exclusion: Lines, pipes, conduit and cables installed under structural concrete decks.
2023 FLORIDA BUILDING CODE EIGHTH EDITION
CHAPTER 1 – SCOPE AND ADMINISTRATION
SECTION 110 INSPECTIONS
110.9 Mandatory structural inspections for condominium and cooperative buildings.
Note: Code language for consistency with SB 4D is not shown here. These provisions have been updated during the 2023 legislative session. See F.S. 553.899 for current language. Further changes are forthcoming. The requirements will be extensive and far reaching. Stay tuned for more information.
Hopefully, this review will help you understand most of the significant roofing-related changes in the 2023 FBC Eighth Edition. It is a complex subject that requires continued review to fully understand the requirements. Please attend the upcoming FRSA seminars and follow this column to keep yourself up to date. I have often heard this statement: “I don’t worry about the building code, I do more than it requires.” If you don’t know what’s in it and what has changed, how do you know that?
Mike Silvers, CPRC, is owner of Silvers Systems Inc. and is consulting with FRSA as Director of Technical Services. Mike is an FRSA Past President, Life Member and Campanella Award recipient and brings over 50 years of industry knowledge and experience to FRSA’s team.
Next Article