New Mexico Administrative Code › Title 14 - HOUSING AND CONSTRUCTION › Chapter 7 - BUILDING CODES GENERAL › Part 3 - 2021 NEW MEXICO RESIDENTIAL BUILDING CODE › Section 14.7.3.15 - CHAPTER 7 WALL COVERING

Current through Register Vol. 35, No. 13, July 16, 2024
See this chapter of the IRC except as provided below.
A.
Section R702.7 Vapor
				retarders.
See this section of the IRC except as follows: Vapor retarder
				materials shall be classified in accordance with Table R702.7(1). A vapor
				retarder shall be provided on the interior side of frame walls of the class
				indicated in Table R702.7(2), including compliance with Table R702.7(3) or
				R702.7(4) where applicable. An approved design using accepted engineering
				practice for hygrothermal analysis shall be permitted as an alternative. The
				climate zone shall be determined in accordance with the Climate Zone Chart in
				14.7.6 NMAC, New Mexico Residential Energy Conservation Code.
B.
Section R703 Exterior
				covering.
See this section of the IRC except as follows.
(1)
Section R703.7.2 Plaster.
Insert the following at the end of the second paragraph: Plastering with
				Portland cement plaster shall be not less than three coats when applied over
				metal lath or wire lath and shall be not less than two coats when applied over
				masonry, concrete, pressure-preservative treated wood, or decay-resistant wood
				as specified in Section R317.1 or gypsum backing. If the plaster surface is
				completely covered by veneer or other facing material or is completely
				concealed, plaster application need be only two coats, provided the total
				thickness is as set forth in Table R702.1 (1). On wood-frame construction with
				an on-grade floor slab system, exterior plaster shall be applied to cover, but
				not extend below, lath, paper, and screed. All residual plaster or stucco
				material that accumulates at the base of the wall shall be removed before it is
				allowed to cure and no horizontal plaster or stucco material shall remain on
				the adjacent grade, footing, footing trench or, when provided, weep screed. All
				residual stucco material shall be removed from roof surfaces and roof
				substrates before it is allowed to cure. The proportion of aggregate to
				cementitious materials shall be as set forth in Table R702.1(3).
Exception:
Exterior plaster may be continued below the weep screed
				to below grade provided there is a complete break in the drainage plane of the
				building at the location of the horizontal weep screed. Weep holes in the
				screed shall not be plugged during the application of plaster materials used to
				cover foundation insulation.
(2)
Section R703.7.2.1 Weep screeds.
Delete the text of this section
				of the IRC and substitute with the following: When an approved acrylic based
				exterior finish stucco system or acrylic based color coat is applied, a minimum
				0.019 inch (0.48 mm) (No. 26 galvanized sheet gage), corrosion-resistant weep
				screed or plastic weep screed, with a minimum vertical attachment flange of
				three half inches (89 mm) shall be provided at or below the foundation plate
				line on exterior stud wall in accordance with ASTM C 926. The weep screed shall
				be placed a minimum of four inches (51mm) above the earth or half inch 13 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 lap the attachment flange of the
				weep screed. Weep screeds are not required under covered porches or covered
				patios.
(3)
Section R703.7.3
				Water-resistive barriers.
Delete this section of the IRC and substitute
				with the following: Water-restive barriers shall be installed as required in
				Section R703.2 and where applied over wood-based sheathing, shall include a
				water-resistive vapor-permeable barrier with performance at least equivalent to
				two layers of Grade D paper. Such felt or material shall be applied
				horizontally, with the upper layer lapped over the lower layer not less than
				two inches (51mm). Where vertical joints occur, the material and or felt shall
				be lapped not less than six inches (152mm).