Minnesota Legislature
Office of the Revisor of Statutes
Minnesota Administrative Rules
1309.0703 SECTION R703, EXTERIOR COVERING.
Subp. 3.
Section R703.6.
IRC Section R703.6 is amended to read as follows:
R703.6 Exterior plaster. Installation of these materials shall be in compliance with ASTM C 926-98a and ASTM C 1063-03 and provisions of this code.
R703.6.1 Lath. All lath and lath attachments shall be of corrosion-resistant materials. Expanded metal or woven wire lath shall be attached with 11 gage nails having a 7/16-inch (11.1 mm) head or 16 gage staples, spaced at no more than 6 inches (152 mm) or as otherwise approved. Nails or staples shall penetrate wood framing support members not less than 3/4-inch (19 mm).
R703.6.2.1 Weep screeds. A minimum 0.019-inch (No. 26 galvanized sheet gage), corrosion-resistant weep screed or plastic weep screed, with a minimum vertical attachment flange of 3-1/2 inches (89 mm) shall be provided at or below the foundation plate line on exterior stud walls in accordance with ASTM C 1063-03. The weep screed shall be placed a minimum of 4 inches (102 mm) above the earth or 2 inches (51 mm) above paved areas and shall be of a type that will allow trapped water to drain to the exterior of the building. The weather-resistant barrier shall lap the attachment flange. The exterior lath shall cover and terminate on the attachment flange of the weep screed.
R703.6.1.3 Control joints and expansion joints. Provisions for the control of expansion shall be determined by the exterior plaster application designer. ASTM C 1063-03 sections 7.11 4 - 7.11 4.4 do not apply.
R703.6.3 Water-resistive barriers. Water-resistive barriers shall be installed as required in Section R703.2 and, where applied over wood-based sheathing, shall include two layers of a water-resistive vapor-permeable barrier. Each layer shall meet both of the following requirements:
1. A water resistance not less than that of 60-minute Grade D paper; or a minimum hydrostatic head of 60.9 cm when tested in accordance with hydrostatic pressure test method AATCC 127-1998; or a minimum water transudation time of 60 minutes when tested in accordance with ASTM D-779.
2. A water vapor permeance not less than that of no. 15 felt; or a minimum permeance rating of 8.5 gr/h.ft.2 in Hg (US perm) (4.9 x 1010 kg/Pa.s.m2) when tested in accordance with Procedure B of ASTM E96.
Exception: One layer of water-resistive barrier complying with R703.2 is permitted when a drainage space that allows bulk water to flow freely behind the cladding is provided.
Subp. 3a.
Section R703.7.
IRC Section R703.7 is amended by adding the following sentence to the end of Section R703.7: For structures in 90 mph wind speed region apply Seismic Design Category A limitations and requirements of Exception 1 and Table R703.7(1).
Subp. 8a.
Section R703.7.4.2.
IRC Section R703.7.4.2 is amended to read as follows:
R703.7.4.2 Air space. The veneer shall be separated from the sheathing by an air space of a minimum of a nominal 1 inch (25 mm) but nor more than 4-1/2 inches (114 mm).
Exception: One layer of water-resistive barrier complying with Section R703.2 is permitted when a drainage space that allows bulk water to flow freely behind the cladding is provided.
Subp. 8b.
Section R703.7.4.3.
IRC Section R703.7.4.3 is amended to read as follows:
R703.7.4.3 Mortar or grout fill. As an alternate to the air space required by Section R703.7.4.2, mortar or grout shall be permitted to fill the air space. When the 1-inch (25.4 mm) space is filled with mortar, a weather-resistant membrane or building paper as described in Section R703.2 or R703.6.3 is required over studs or sheathing. When filling the air space, it is permitted to replace the sheathing and weather-resistant membrane or asphalt-saturated felt paper with a wire mesh and approved paper or an approved paper-backed reinforcement attached directly to the studs.
R703.7.4.4 Masonry veneer on sheathed substrates. On sheathed substrates, a corrosion-resistant, self-furring expanded metal lath shall be installed over the weather-resistant membrane or building paper with appropriate fasteners as described in Section R703.6.1. Fasteners shall penetrate wood supports a minimum of one inch.
Subp. 9.
Section R703.8.
IRC Section R703.8 is amended to read as follows:
R703.8 Flashing. Approved corrosion-resistant flashing shall be applied shingle-fashion in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashing shall be installed at all of the following locations:
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 for subsequent drainage.
2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.
3. Under and at the ends of masonry, wood, or metal copings and sills.
4. Continuously above all projecting wood trim.
5. Where exterior porches, decks, or stairs attach to a wall or floor assembly of wood-frame construction.
6. At wall and roof intersections.
7. At built-in gutters.
8. Where exterior material meets in other than a vertical line.
9. Where the lower portion of a sloped roof stops within the plane of an intersecting wall cladding in such a manner as to divert or kick out water away from the assembly.
R703.8.1 Pan flashing of windows and doors. A pan flashing shall be provided under all exterior windows and doors. Pan flashing shall be (a) sloped to drain water to the exterior surface of a weather-resistive barrier or flat with sealed back dam and side dams to prevent re-entry of water into the wall cavity or onto interior finishes, and (b) maintain the thermal envelope of the building. Pan flashing made from metal must be thermally isolated from interior surfaces.
Exceptions:
1. Windows or doors installed in accordance with the manufacturer's installation instructions which include an alternate flashing method.
2. Windows or doors in detached accessory structures.
3. Skylights, bow or bay windows.
4. Doors required to meet accessibility requirements that would prevent the installation of pan flashing.
5. Repairs or replacement of existing windows and doors.
6. When a method is provided by a registered design professional.
History:
27 SR 1475; 32 SR 12; L 2007 c 140 art 4 s 61; art 13 s 4
Published Electronically:
February 23, 2009
Official Publication of the State of Minnesota
Revisor of Statutes