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ESR-1475 Page 3 of 14
<br />board (OSB); or nominally 1-inch-by-6-inch lumber installed as solid sheathing conforming to 2024 IBC
<br />Sections 2304.8.2 or 2308.11.9 (2021, 2018 and 2015 IBC Sections 2304.8.2 or 2308.7.10; 2012, 2009 and
<br />2006 IBC Section 2304.7.2 or 2308.10.8) or IRC Sections R803, as applicable, and underlayment in
<br />accordance with Sections 3.3 and 4.1.2.3. Minimum roof slope must be 2:12 (16.7 percent).
<br />4.1.2 Application:
<br />4.1.2.1 Fastening: Fasteners are as described in Section 3.2. Shingles must be fastened to the roof deck
<br />with a minimum of four fasteners or as shown in the Standard Nailing Pattern in Figure 1. Spacing of fasteners
<br />must be as shown in Figure 1, and each course of shingles must be offset from the preceding course as shown
<br />in the manufacturer’s published installation instructions.
<br />4.1.2.2 Shingle Sealing: In colder climates or wind regions where it is questionable whether the factory-
<br />applied adhesive will activate and seal the shingles, to ensure sealing, the shingles must be hand-sealed with
<br />a minimum of three 1-inch-diameter (25.4 mm) spots of asphalt roofing cement equally spaced on the
<br />unexposed surface across each shingle. For applications on slopes greater than 21:12, hand-sealing is
<br />required. Hand-sealing consists of applying a minimum of three 1-inch-diameter (25.4 mm) spots of asphalt
<br />roofing cement on the unexposed surface, equally spaced across each shingle. For three–tab and five–tab
<br />shingles, one spot of asphalt roofing cement is placed under each corner of each tab (two spots per tab); the
<br />tab must then be pressed into the cement. For laminated shingles, four equally spaced spots of asphalt roofing
<br />cement are placed under the exposed portion of the shingle; the shingle must then be pressed into the cement.
<br />See the manufacturer’s published installation instructions for hand-sealing guidelines. The shingles must be
<br />hand-sealed to the satisfaction of the code official.
<br />4.1.2.3 Underlayment: Under the 2024, 2021 and 2018 IBC, the roof underlayment must be installed in
<br />accordance with Section 1507.1.1 and Tables 1507.1.1(2) and 1507.1.1(3). Under the 2015, 2012, 2009 and
<br />2006 IBC, the roof underlayment must be installed in accordance with Section 1507.2.8. Under the 2024, 2021,
<br />2018 and 2015 IRC, the roof underlayment must be installed in accordance with Section R905.1.1 and Tables
<br />R905.1.1(2) and Table R905.1.1(3). Under the 2012, 2009 and 2006 IRC, the roof underlayment must be
<br />installed in accordance with Section R905.2.7. Minimum roof slope must be 2:12 (17-percent). For roof slopes
<br />greater than 4:12, the roof deck must be covered with a minimum of one layer of underlayment as described
<br />in Section 3.3 of this report. For slopes between 2:12 and 4:12, two layers of the underlayment described in
<br />Section 3.3 of this report are required or, alternatively, one layer of ASTM D1970 complying underlayment is
<br />required for all slopes 2:12 or greater. In areas where there has been a history of ice forming along the eaves,
<br />causing a backup of water, an ice barrier must be provided in accordance with 2024, 2021 and 2018 IBC
<br />Section 1507.2.7 (2015, 2012, 2009 and 2006 IBC Section 1507.2.8.2) or 2024, 2021, 2018 and 2015 IRC
<br />Section R905.2.7 (2012, 2009 and 2006 IRC Section R905.2.7.1), as applicable.
<br />4.2 Hip and Ridge Cap Shingles:
<br />Hip and ridge cap shingles must be placed evenly over hips and ridges (or over shingle-over ridge vents), and
<br />fastened to the roof deck with two fasteners, described in Section 3.2 of this report, located on either side of
<br />the shingle, on the fastener line shown in Figure 1. Staples must not be used to fasten the ridge cap shingles.
<br />4.3 Installation—Reroofing:
<br />When installed over existing Class A or Class C asphalt shingle roofs in accordance with this section, the
<br />shingles described in this report are recognized as a Class A roof covering. The existing asphalt shingle roof
<br />covering must be inspected in accordance with the provisions and limitations of 2024 and 2021 IBC Section
<br />1512 [2018 and 2015 IBC Section 1511 (2012, 2009 and 2006 IBC Section 1510)] or 2024, 2021, 2018 and
<br />2015 IRC Section R908 (2012, 2009 and 2006 IRC Section R907). Prior to the reroofing, hip and ridge covering
<br />must be removed. Except as noted in this section, the shingles must be installed in accordance with Section
<br />4.1 of this report. Fasteners must be of sufficient length to penetrate 3/4 inch (19.1 mm) into the sheathing, or
<br />through the sheathing, whichever is less. Flashing and edging must comply with the following, as applicable:
<br />•IBC: 2024 and 2021 IBC Section 1512.4 and 1512.5 [2018 and 2015 Sections 1511.5 and 1511.6 (2012,
<br />2009 and 2006 Sections 1510.5 and 1510.6)].
<br />•IRC: 2024, 2021, 2018 and 2015 Sections R908.5 and R908.6 (2012, 2009 and 2006 Sections R907.5
<br />and R907.6).
<br />4.4 Wind Resistance:
<br />GAF asphalt shingles have been tested for wind resistance in accordance with ASTM D3161 and/or ASTM
<br />D7158. Shingles tested in accordance with ASTM D3161 are classified as Class F and qualify for use under
<br />2024 and 2021 IBC Section 1504.2 [2018 and 2015 IBC Section 1504.1.1 (2012 and 2009 IBC Section
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