Asphalt Shingle Underlayment & Drip Edge Checklist (Outside HVHZ)
Install asphalt shingles per FBC Residential Section R905.2 or, as an alternative, RAS 115.
FBC-R R905.2 ↗Asphalt shingles go only on solidly sheathed decks with a slope of 2:12 or steeper.
FBC-R R905.2.1; FBC-R R905.2.2 ↗Underlayment must meet R905.1.1, and ASTM D226, D1970, D4869, D6757 or D8257 products must be labeled with the standard and type.
FBC-R R905.2.3; FBC-R R905.1.1 ↗Underlayment option 1: cover the entire deck with ASTM D1970 self-adhered polymer-modified bitumen underlayment installed per the underlayment and shingle manufacturers.
FBC-R R905.1.1.1 Item 1 ↗Underlayment option 2: apply 3-3/4 inch minimum ASTM D1970 strips or AAMA 711 Level 3 tape over all deck joints, then cover the roof with underlayment per Table R905.1.1.1.
FBC-R R905.1.1.1 Item 2 ↗Underlayment option 3: install two layers of ASTM D226 Type II, D4869 Type III/IV or D8257 underlayment (half-sheet starter course, then each course lapped half a sheet plus 1-2 inches, 6-inch end laps offset 6 feet).
FBC-R R905.1.1.1 Item 3 ↗With the joint-strip method, slopes of 4:12 and up get underlayment lapped 4 inches, while slopes from 2:12 to under 4:12 must use the two-layer method.
FBC-R Table R905.1.1.1 ↗Fasten mechanically attached underlayment with ring- or deformed-shank cap nails (1-inch caps) on a 12-inch grid and 6 inches at laps; caps must be 32-gauge metal where Vult is 170 mph or more, and nails must penetrate through or 3/4 inch into the sheathing.
FBC-R R905.1.1.1 Item 3; FBC-R Table R905.1.1.1 ↗Shingle nails must be galvanized, stainless, aluminum or copper, 12-gauge with a 3/8-inch head (ASTM F1667), penetrating at least 3/4 inch into the sheathing or through it.
FBC-R R905.2.5 ↗Use the manufacturer's nail count but never fewer than four nails per strip shingle (two per individual shingle), following the manufacturer's method above 21:12.
FBC-R R905.2.6 ↗Shingles must be wind-classified to ASTM D7158 (D, G or H) or D3161 (D or F) for the site's wind speed per Table R905.2.6.1 (for example, Class H or F at 168 mph and up), with the class printed on the wrapper.
FBC-R R905.2.6.1; FBC-R Table R905.2.6.1 ↗Install drip edge at eaves and gables with laps of at least 3 inches, extending 1/2 inch below the sheathing and at least 2 inches back onto the roof.
FBC-R R905.2.8.5 ↗Install drip edge over the underlayment (self-adhered D1970 may go over a primed flange) and run a 4-inch-wide strip of roof cement over the flange or the self-adhered underlayment.
FBC-R R905.2.8.5 ↗Nail drip edge at most 12 inches on center, or at most 4 inches on center where Vasd is 110 mph or more or the mean roof height is over 33 feet.
FBC-R R905.2.8.5 ↗Open metal valleys need lining at least 16 inches wide; closed valleys may use 36-inch ASTM D1970 self-adhered underlayment instead of the lining material.
FBC-R R905.2.8.2 ↗
- The 9th Edition (2026) Florida Building Code takes effect December 31, 2026, per Miami-Dade County; the Florida Building Commission workplan lists the same date and notes the code takes effect 6 months after publication.
- FBC-R R905.2.8.5: drip edge must be mechanically fastened 4 inches on center statewide, with fasteners complying with R905.2.5.
- FBC-R R905.1.1: underlayment must lap over hips and ridges at least 6 inches, except where ventilation openings are provided.
- New FBC-R R905.2.6.2: hip and ridge shingles must be tested to UL 2375 (modified to 110 mph) and labeled, or set with 1-inch spots of roof cement in addition to the required fasteners.
- FBC-R R905.2.5 fastener rules now also cover hip and ridge shingles; R905.2.6 is retitled 'Fastening' and adds wording for interlocking shingles; the 'printed' manufacturer-instructions requirement in R905.2.8.4 is removed.
Official sources
- 2023 FBC Residential, 8th Ed., Chapter 9 Roof Assemblies (ICC) ↗
- Florida Building Commission: Analysis of Changes, 9th Ed. (2026) FBC Residential ↗
- Miami-Dade County: FBC Ninth (2026) Edition effective date notice ↗
- Florida Building Commission: 2026 FBC Workplan (October 2026) ↗
A summary to help you prepare, not the code itself. Always confirm with the code and your building department.