Okla. Admin. Code § 748:20-6-12

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

Section 748:20-6-12 - IRC[®] 2018 Chapter 7 Wall Covering

Chapter 7 of the IRC® 2018 is adopted with the following modifications:

(1) Section 703.1 General. This section has been modified to clarify and add requirements for direct applied exterior finish with water-resistive barrier installations. This section has been modified to read: 703.1 General. Exterior walls shall provide the building with a weather- resistive exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.4. Direct Applied Exterior Finish Systems Cement Board based stucco finish and direct applied masonry or stone shall comply with the following:

(A) Item 1. Direct applied masonry or stone shall comply with Section R703.7.3 Water- resistive barriers and product manufacture's installation specifications.

(B) Item 2. Cement Board Stucco Exterior Finish Systems shall be installed per manufacturer installation instructions and meet the minimum wall assembly details below. Products that make up the finished wall system that consists of base coat, secondary coat, reinforcing mesh and finish coat shall be of same manufacturer to ensure product/material compatibility and performance.

(i) Item 2.1. Approved Sheathing.

(ii) Item 2.2. Base flashing at bottom of walls and roofs.

(iii) Item 2.3. Water resistant barrier equal to or greater than 60-minute Grade D paper or ASTM D226.

(iv) Item 2.4. Approved Cement Board for wall application base for exterior wall ASTM C1326.

(v) Item 2.5. Approved Cement Board Joint Reinforcement Coat and Mesh.

(vi) Item 2.6. Base Coat.

(vii) Item 2.7. Reinforcing Mesh ASTM E2098(Alkaline Resistant).

(viii) Item 2.8. Second Base Coat.

(ix) Item 2.9. Finish Coat.

(x) Item 2.10. Other Design Considerations: Separation distance from finish exterior grade must be 6 inches or greater. Separation from roofs must be 1 inch or greater. Through wall flashing must be provided at horizontal locations at dissimilar materials. Expansion joints, if needed, shall comply with finish system manufacturer recommendations. Expansion gaps are required around all windows, doors, or other dissimilar material integrated in the wall and joints are required to be sealed.

(C) Exception: Log walls designed and constructed in accordance with the provisions of ICC 400®.

(2) Section R703.4 Flashing. This section has been modified to clarify that 6-mil polyethylene sheeting is an approved corrosion-resistant flashing in certain circumstances and to clarify flashing above doors is not required when the door is covered by a minimum of 3 feet. This section has been modified to read: R703.4 Flashing. Approved corrosion- resistant flashing shall be applied shingle-fashion in a manner to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. 6-mil polyethylene sheeting is an approved corrosion-resistant flashing when not exposed to UV rays. Self-adhered membranes used as flashing shall comply with AAMA 711. Fluid-applied membranes used as flashings in exterior walls shall comply with AAMA 714. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashings shall be installed at the following locations:

(A) Item 1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier complying with Section R703.2 for subsequent drainage. Mechanically attached flexible flashings shall comply with AAMA 712. Flashing at exterior window and door openings shall be installed in accordance with one or more of the following:

(i) Item 1.1. The fenestration manufacturer's installation instructions and flashing instructions, or for applications not addressed in the fenestration manufacturer's instructions in accordance with the flashing manufacturer's instructions. Where flashing instructions or details are not provided, flashing to be installed per 1.2, 1.3, 1.4 or, pan flashing shall be installed at the sill of exterior window and door openings. Pan flashing shall be sealed or sloped in a such a manner as to direct water to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage. Openings using pan flashing shall incorporate flashing or protection at the head and sides.

(ii) Item 1.2. In accordance with the flashing design or method of a registered design professional.

(iii) Item 1.3. In accordance with other approved methods.

(iv) Item 1.4. Flashing above doors are not required where the door is covered by a minimum of 3 feet.

(B) Item 2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.

(C) Item 3. Under and at the ends of masonry, wood or metal copings and sills.

(D) Item 4. Continuously above all projecting wood trim.

(E) Item 5. Where exterior porches, decks, or stairs attach to a wall or floor assembly of wood-frame construction.

(F) Item 6. At wall and roof intersections.

(G) Item 7. At built-in gutters.

(3) Section 703.7.3 Water-resistive barriers. This section has been modified to clarify the requirements for the water-resistive barrier, where applied over approved sheathing to drain to the outer water-resistive barrier. This section has been modified to read: 703.7.3 Water- resistive barriers. Water-resistive barriers shall be installed as required in Section R703.2 and, where applied over approved sheathing, shall include a water-resistive vapor-permeable barrier with a performance at least equivalent to two layers of Grade D paper. The individual layers shall be installed independently such that each layer provides a separate continuous plane and any flashing, installed in accordance with Section R703.4 and intended to drain to the outer water-resistive barrier. Exception: Where the water-resistive barrier that is applied over wood-based sheathing has a water resistance equal to or greater than that of 60 -minute Grade D paper and is separated from the stucco by an intervening, sustainably nonwater- absorbing layer or designed drainage space.

(4) Section R703.8 Anchored stone and masonry veneer, general. This section has been modified to specify anchored stone walls shall have an additional layer of No. 15 asphalt felt complying with ASTM D226 for Type I felt or other water-resistive barrier to provide a bond break between the primary water-resistive barrier and the back side of the stone and mortar. This section has been modified to read: R703.8 Anchored stone and masonry veneer, general. Anchored stone and masonry veneer shall be installed in accordance with this chapter, Table R703.3(1) and Figure R703.8. These veneers installed over a backing of wood or cold-formed steel shall be limited to the first story above grade plane and shall not exceed 5 inches (127 mm) in thickness. See Section R602.10 for wall bracing requirements for masonry veneer for wood-framed construction and Section R603.9.5 for wall bracing requirements for masonry veneer for cold-formed steel and connections. Anchored stone walls shall have an additional layer of No. 15 asphalt felt complying with ASTM D226 for Type I felt or other approved water-resistance barrier to provide a bond break between the primary water-resistive barrier and the back side of stone or mortar. Exceptions:

(A) Exception 1. For buildings in Seismic Design Categories A, B, and C, exterior stone or masonry veneer, as specified in Table R703.8(1) with a backing of wood or steel framing shall be permitted to the height specified in Table R703.8(1) above a noncombustible foundation.

(B) Exception 2. For detached one- and two-family dwellings in Seismic Design Categories D (subscript 0), D (subscript 1), and D (subscript 2), exterior stone or masonry veneer, as specified in Table 703.8(2) with a backing of wood framing shall be permitted to the height specified in Table 703.8(2) above a noncombustible foundation.

(5) Figure R703.8 Typical Masonry Veneer Wall Details. This figure has been modified to add footnotes "f" and "g" to the footnote section and amend the figure heading to include a superscript "f" and "g" to indicate the associated footnotes. This figure's footnotes have been modified to read:

(A) Footnote "a" reads: "See Sections R703.4, R703.8.5, and R703.8.6."

(B) Footnote "b" reads: "See Section R703.2 and R703.8.4."

(C) Footnote "c" reads: "See Section R703.8.4. and Table R703.8.4.2."

(D) Footnote "d" reads: "See Section R703.8.3."

(E) Footnote "e" reads: "Figure R703.8 illustrates typical construction details for a masonry veneer wall. For the actual mandatory requirements of this code, see the indicated sections of text. Other details of masonry veneer wall construction shall be permitted provided the requirements of the indicated sections of text are met.

(F) Footnote "f" reads: "Flashing to be done per Section R703.4, in accordance with a design from a registered design professional or in accordance with other approved methods or standard industry practices."

(G) Footnote "g" reads: "Flashing depicted under sill and above windows are not required with windows that have flanges for their primary attachment. Flange type windows shall be counter flashed into the weather-resistant barrier or installed per Section R703.4 and per window manufacturer's installation instructions."

(6) Figure R703.8.2.1 Exterior Masonry Veneer Support by Steel Angles. This figure has been modified by adding a footnote to the figure. The figure heading has been modified to have a superscript letter "a" to indicate a new footnote is applicable. Footnote "a" has been added to read:

a. Flashing to be done per Section R703.4, in accordance with a design from a registered design professional or other approved methods as defined by the code for wall flashing.

(7) Figure R703.8.2.2 Exterior Masonry Veneer Support by Roof Members. This figure has been modified by adding a footnote "a" to the figure. The figure heading has been modified to have a superscript letter "a" to indicate a new footnote is applicable. Footnote "a" has been added to read:

a. Flashing to be done per Section R703.4, in accordance with a design from a registered design professional or other approved methods as defined by the code for wall flashing.

(8) Section R703.8.3.1 Allowable span. This section has been modified to provide guidance to builders using, a typical for Oklahoma, lintel. This section has been modified to read: R703.8.3.1 Allowable span. The allowable span shall not exceed the values set forth in Table R703.8.3.1. Additionally, a 3 inches x 3 inches x 3/16 inch (76 mm x 76 mm x 4.8 mm) steel angle 6 feet (1829 mm) long may be used to support 3 vertical feet (914 mm) of masonry veneer and a 3 inches x 3 inches x 3/16 inch (76 mm x 76 mm 4.8 mm) steel angle 5 feet (1524 mm) long may be used to support 4 1/4 vertical feet (1295 mm) of masonry veneer.

(9) Section R703.9.1 Exterior insulation and finish systems (EIFS). This section has been modified to clarify EFIS shall be installed in accordance with the same product manufacturer's instructions to ensure product/material compatibility and performance. This section has been modified to read: R703.91. Exterior insulation and finish systems (EIFS). EIFS shall comply with the following:

(A) Item 1. ASTM E2568.

(B) Item 2. EIFS shall be limited to applications over substrates of concrete or masonry wall assemblies.

(C) Item 3. Flashing of EIFS shall be provided in accordance with the requirements of Section R703.4.

(D) Item 4. EIFS shall be installed in accordance with same manufacturer's instruction as to ensure product/material compatibility and performance.

(E) Item 5. EIFS shall terminate not less than 6 inches (152 mm) above the finished ground level.

(F) Item 6. Decorative trim shall not be face-nailed through the EIFS.

(10) Section R703.9.2 Exterior insulation and finish systems (EIFS) with drainage. This section has been modified to clarify EFIS shall be installed in accordance with the same product manufacturer's instructions to ensure product/material compatibility and performance. This section has been modified to read: R703.9.2 Exterior insulation and finish systems (EIFS) with drainage. EIFS with drainage shall comply with the following:

(A) Item 1. ASTM E2568.

(B) Item 2. EIFS with drainage shall be required over all wall assemblies with the exception of substrates of concrete or masonry wall assemblies.

(C) Item 3. EIFS with drainage shall have an average minimum drainage efficiency of 90 percent when tested in accordance with ASTM E2273.

(D) Item 4. The water-resistive barrier shall comply with Section R703.2 or ASTM 2570.

(E) Item. 5. The water-resistive barrier shall be applied between the EIFS and the wall sheathing.

(F) Item 6. Flashing of EIFS with drainage shall be provided in accordance with the requirements of Section R703.4.

(G) Item 7. EIFS with drainage shall be installed in accordance with the same manufacturer's instructions to ensure product/material compatibility and performance.

(H) Item 8. EIFS with drainage shall terminate not less than 6 inches (152 mm) above the finished ground level.

(I) Item 9. Decorative trim shall not be face-nailed through the EIFS.

Okla. Admin. Code § 748:20-6-12

Amended and renumbered from 748:20-5-10 by Oklahoma Register, Volume 39, Issue 24, September 1, 2022, eff. 9/14/2022