Okla. Admin. Code § 748:20-6-14

Current through Vol. 42, No. 3, October 15, 2024

Section 748:20-6-14 - IRC[®] 2018 Chapter 9 Roof Assemblies

Chapter 9 of the IRC® 2018 is adopted with the following modifications:

(1) Section 905.1.2 Ice barriers. This section has been modified to add two more paragraphs to the section to require 36-inch wide ice barriers to be installed on the roof under specific conditions and in specific locations. This section has been modified to read:

(A) 905.1.2 Ice barriers. In areas where there has been a history of ice forming along the eaves causing a backup of water as designated in Table R301.2(1), an ice barrier shall be installed for asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes. The ice barrier shall consist of not fewer than two layers of underlayment cemented together, or a self-adhering polymer- modified bitumen sheet shall be used in place of normal underlayment and extend from the lowest edges of all roof surfaces to a point not less than 24 inches (610 mm) inside the exterior wall line of the building. On roofs with a slope equal to or greater than eight units vertical in 12 units horizontal (67 percent slope), ice barrier shall also be applied not less than 36 inches (914 mm) measured along the roof slope from the eave edge of the building.

(B) A 36-inch wide (914 mm) ice barrier shall be installed in all valleys, run the length of the valley, and centered on the valley.

(C) A 36-inch wide (914 mm) ice barrier shall be installed at all change in roof pitch in which the lower roof has a lower pitch than the upper roof. The ice barrier is run the length of the change in pitch and cemented on the change in pitch.

(2) Section R905.2.1 Sheathing requirements. This section has been modified to add a definition for the term "solidly sheathed." This section has been modified to read: R905.2.1 Sheathing requirements. Asphalt shingles shall be fastened to solidly sheathed decks. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacturer's installation instructions, warped, split, cracked, deteriorated or rotten boards).

(3) Section R905.2.8.5 Drip edge. This section has been modified to add an exception to the section when certain criteria is met. This section has been modified to read: R905.2.8.5 Drip edge. A drip edge shall be provided at eaves and rake edges of shingle roofs. Adjacent segments of drip edge shall be overlapped not less than 2 inches (51 mm). Drip edges shall extend not less than 1/4 inch (6.4 mm) below the roof sheathing and extend up back onto the roof deck not less than 2 inches (51 mm). Drip edges shall be mechanically fastened to the roof deck at not less than 12 inches (305 mm) o.c. with fasteners as specified in Section R905.2.5. Drip edges shall be installed over the underlayment along rake edges. Exception: If a nominal 1 inch by 2 inch (25 mm by 51 mm) shingle mold is used, attached to the fascia and the starter course of shingles is extended a minimum of 1/4 inch (6.35 mm) and not more than 1 inch (25 mm) then a metal drip edge is not required.

(4) R905.3.1. Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.3.1. Deck requirements. Concrete and clay tile shall be installed only over solid sheathing or spaced structural sheathing boards. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(5) 905.4.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.4.1 Deck requirements. Metal roof shingles shall be applied to a solid or closely fitted deck, except where the roof covering is specifically designed to be applied to spaced sheathing. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(6) Section 905.5.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.5.1 Deck requirements. Mineral-surfaced roll roofing shall be fastened to solidly sheathed roofs. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(7) Section R905.6.2 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.6.2 Deck requirements. Slate shingles shall be fastened to solidly sheathed roofs. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(8) Section R905.7.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.7.1 Deck requirements. Wood shingles shall be installed on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall be not less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(9) Section R905.8.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.8.1 Deck requirements. Wood shakes shall be used only on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall be not less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners. Where 1-inch by 4- inch (25 mm by 102 mm) spaced sheathing is installed at 10 inches (254 mm) on center, additional 1-inch by 4-inch (25 mm by 102 mm) boards shall be installed between the sheathing boards. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(10) Section R905.10.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.10.1 Deck requirements. Metal roof panel roof coverings shall be applied to solid or spaced sheathing, except where the roof covering is specifically designed to be applied to spaced supports. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(11) Section R905.16.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.16.1 Deck requirements. Photovoltaic shingles shall be applied to a solid or closely fitted deck, except where the roof covering is specifically designed to be applied over spaced sheathing. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(12) Section R905.17.1 Deck requirements. This section has been modified to provide a definition for the term "solidly sheathed." This section has been modified to read: R905.17.1 Deck requirements. BIPV roof panels shall be applied to a solid or closely-fitted deck, except where the roof covering is specifically designed to be applied over spaced sheathing. Solidly sheathed decks shall be defined as sawn lumber boards or structural panels that provide a solid holding power for fasteners that do not have deficit conditions (gaps greater than those allowed by the roof covering manufacture's installation instructions, warped, split, cracked deteriorated or rotten boards).

(13) Section R908.3.1.1 Roof re-cover. This section has been modified to list a fourth condition for when a roof re-cover shall not be permitted. This section has been modified to read: R908.3.1.1. Roof re-cover. A roof re-cover shall not be permitted where any of the following conditions occur:

(A) Item 1. 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.

(B) Item 2. Where the existing roof covering is slate, clay, cement or asbestos-cement tile.

(C) Item 3. Where the existing roof has two or more applications of any type of roof covering.

(D) Item 4. Where the existing roof has one or more application of asphalt shingles additional applications of asphalt shingles shall not be permitted.

Okla. Admin. Code § 748:20-6-14

Amended and renumbered from 748:20-5-11.1 by Oklahoma Register, Volume 39, Issue 24, September 1, 2022, eff. 9/14/2022