GUIDE SPECIFICATIONS 9 FOR EXPANDED METAL …

1 EMLA 920A Division ofNATIONAL ASSOCIATION OFARCHITECTURAL METAL MANUFACTURERSNAAMM EMLA 920-09 December 2009 METAL LATHING AND FURRING9 NAAMM EMLA 920-09 December 2009 METAL LATHING AND FURRING9-09 NAAMMSTANDARDGUIDE SPECIFICATIONSFOR EXPANDED METALLATHING AND FURRINGF ifth EditionEMLA22134_Cover 1/7/10 9:49 AM Page 2 DISCLAIMERThis manual was developed by representative members of theExpanded METAL Lath Association Division of the National Association ofArchitectural METAL Manufacturers (EMLA) to provide information andguidance on the manufacture of METAL lath SPECIFICATIONS . This manualcontains advisory information only and is published as a public serviceby NAAMM and its AND ITS EMLA DIVISION DIS-CLAIMALL LIABILITY OF ANY KIND FOR THE USE, APPLICATION,OR ADAPTATION OF MATERIAL PUBLISHED IN THIS Association of Architectural METAL Manufacturers800 Roosevelt Road Glen Ellyn, Illinois 60137 1-630-942-6591 Fax 1-312-332-0706 Website: 1981, 1984, 1986, 1991, 2003, 2009By National Association of Architectural METAL Manufacturers, All Rights Reserved22134_Cover 1/7/10 9:49 AM Page 3 TABLE OF CONTENTS1.

2 1 2. Referenced Documents .. 1 ASTM 1 Federal 13. Definitions .. 14. Delivery of Materials .. 15. Storage of 16. Materials, 17. Installation, General .. 28. METAL Lathing on Exteriors (Stucco): Materials .. 49. METAL Lathing on Exteriors (Stucco); Installation .. 510. Non-load Bearing Steel Stud PartitionsWith METAL Lath Both Sides: 611. Non-load Bearing Steel Stud PartitionsWith METAL Lath Both Sides: Installation .. 612. METAL Furring for Walls (Covered One Side): Materials .. 713. METAL Furring for Walls (Covered One Side): 714. Direct Attached Furring: Materials .. 815. Direct Attached Furring: 816. METAL Lath on Wood Studs: 817. METAL Lath on Wood Studs: Installation .. 818. Control Joints: Materials .. 819. Expansion Joints: 820. Contact Ceilings: Materials .. 1021. Contact Ceilings: 1022. Furred Ceilings: Materials .. 1023. Furred Ceilings: Installation.

3 1224. Suspended Ceilings: Materials .. 1225. Suspended Ceilings: Installation .. 1226. Beam Boxes: Materials .. 1427. Beam Boxes: 1628. Column Furring: 1629. Column Furring: Installation .. 1630. METAL Lath Reinforcement for Plaster BasesOther than METAL Lath: Materials .. 17 NAAMM EMLA 920-09 METAL LATHING AND FURRINGiHOW TO USE THESE SPECIFICATIONST hese SPECIFICATIONS are a GUIDE for the specification writer, inspector, and contractor concerned with theaspects of METAL lathing and furring for plastered construction. they provide detailed information about manymetal lath and plaster assemblies. In some instances, certain sections may not be applicable, however,Sections 1 through 7 are pertinent to all other sections and must be considered. Sections 6 & 7 containrequirements that apply to all others and should be included in any SPECIFICATIONS prepared using this docu-ment as a and explanatory notes, diagrams, etc.

4 Are inserted within the text where applicable anditalicized. Appendix A provides supplementary information and specification covers the recommended minimum requirements for lath and furring. Other materials maybe used provided their physical characteristics and durability under condition of usage are at least equal tothose 12/18/09 3:25 PM Page iiiMETAL LATHING AND FURRINGNAAMM EMLA Lath Reinforcement for Plaster 18 Design Assumptions and References .. 18 Appendix A .. 20 Ties and Splices .. 20 Lathing and Furring Connections .. 21 Penetration Flashing 24 Control Joints/Expansion Joints .. 25 Appendix B - Design Considerations .. 28 General Notes .. 33 Lathing and Stucco Terminology .. 34 DISCLAIMERThis manual was developed by representative members of theExpanded METAL Lath Association Division of the National Associationof Architectural METAL Manufacturers (EMLA) to provide information andguidance on the manufacture of METAL lath SPECIFICATIONS .

5 This manualcontains advisory information only and is published as a public serviceby NAAMM and its AND ITS ML/SFA DISCLAIMALL LIABILITY OF ANY KIND FOR THE USE, APPLICATION, ORADAPTATION OF MATERIAL PUBLISHED IN THIS 12/18/09 3:26 PM Page iiNAAMM EMLA 920-09 METAL LATHING AND FURRING11. SCOPEThis specification covers the minimum requirementsfor lathing and furring to receive full thickness plas-ter or stucco as specified in ASTM C842 and a specific degree of fire resistance isrequired, details of construction shall be in strictcompliance with reports and appropriate REFERENCED DOCUMENTSASTM StandardsA1008-00 Standard specification for Steel,Sheet, Cold-Rolled, Carbon, Structural, High-Strength: Low-Alloy and High-Strength Low-Alloy with Improved (metric) Commercial Quality gal-vanized steel replaced for Zinc-Coated(Galvanized) Carbon Steel (metric) Standard Specificationfor Steel, Sheet, and Strip, Hot-Rolled, CarbonStructural, High-strength Low-Alloy and HighStrength Low Alloy with Improved Zinc specification for NonstructuralSteel Framing for Application of PortlandCement Based for EXPANDED METAL for the Application ofPortland Cement for Steel Drill Screws for theApplication of Gypsum Panel Products or MetalPlaster Bases to Steel Studs from in.

6 In. in for Steel Drill Screws forthe Application of Gypsum Panel Products orMetal Plaster specification forInstallation of Lathing and Furring to ReceiveInterior and Exterior Portland SpecificationsUU-B-790aBuilding Paper, Vegetable Fiber,(Kraft, Waterproofed, Water Repellent and FireResistant).3. trim, for the purposes of this specifica-tion, shall mean all parts or assemblies used inconjunction with METAL lath and plaster construc-tion to establish grounds, reinforcement, bound-aries, stress relief or isolation, aesthetic appealor to fulfill a utilitarian function principallydesigned to augment the finished plaster or stuc-co installation. They are generally characterizedby such products as corner beads, casing beadsor plaster stop, control joints or expansion joints,foundation weep screeds, drip screeds, reveals,and ventilation screeds or any other membersdeemed necessary to complement the functionof the primary plaster DELIVERY OF materials shall be delivered in the originalpackages, containers or bundles bearing thebrand name and manufacturer s (or supplier s)

7 STORAGE OF materials shall be kept dry, preferably bybeing stored inside and protected from damageto materials or packaging for necessary to store lath outside, materi-als shall be stacked off the ground, supportedon a level platform, and protected from theweather and surface contamination and dam-age to ends, edges or MATERIALS, Lath- as specified in ASTM C847, with orwithout paper backing, shall be fabricated fromhot dipped galvanized steel with a minimumG60 zinc of copper bearing steel for METAL lath isnow obsolete and no longer should be cited incurrent term galvanized refers to carbon steel thathas been coated or galvanized with zinc by thehot-dip term zinc alloy denotes material comprisedof almost pure zinc throughout the thickness ofthe product, with only enough alloy elementsfor of diamond mesh METAL lath (approx-imately 1/4 inch) may be accomplished by rollingintermittent dimples or continuously embossedribs into the mesh.

8 These ribs run longitudinallydown the length of the sheet of Trim- All trim to be anchored in the plas-ter may have perforated, EXPANDED , or solidflanges shaped so as to permit full embedmentSPECIFICATIONS FOR METAL LATHING AND FURRING22134_Body 12/17/09 3:34 PM Page 12 METAL LATHING AND FURRINGNAAMM EMLA 920-09in the plaster to provide a means for accuratealignment, and to secure attachment of the trimto the plaster base. This helps to avoid cracks inthe stucco. Trim shall be designed to receive orto accommodate application of the specifiedplaster trim shall be fabricated from hot-dippedgalvanized steel or zinc steel, with a minimum G60 coat-ing as specified in ASTM A653, and a thick-ness of .0172 as specified in ASTM alloy, as specified in ASTM trim thickness shall be as follows:TABLE 1 AccessoryBase MaterialSteelZinc Alloy(in.)(in.)Corner alloy plaster trims shall be used for instal-lations where abnormal corrosion is possibledue to high humidity and continual moistureexposure as in bath and shower rooms, green-houses, swimming pool areas, etc.

9 , or whereadverse atmospheric conditions may exist,(high saline content or acid rain) such as incoastal regions or heavy industrial reinforcement ( lb/sq. yd.) galvanizedexpanded METAL strip lath bent to form cornerreinforcement. It shall have legs of not less than 2in. in in flat configuration (strip-lath) mayalso be applied diagonally across corner asreinforcement of concentrated stress areas onflat surfaces, such as at corners of door or win-dow openings with strip width not less than 4 furring channels shall have a mini-mum galvanized G60 coating per ASTM A653and physical prosperities shall be as follows:they shall be formed from steel having a mini-mum 33,000 psi yield strength, minimum flangewidth of 1/2inch minimum, in. minimumbare steel thickness and have the followingminimum weights in pounds per 1000 linier (in) Weight (galvanized)3/4 2771 1/2 41425062 1 as specified in ASTM A641, galvanized,soft temper class 1 coating and Strap hangers shall be of mild steelper ASTM A1008 with rust inhibitive coating orgalvanized commercial quality steel per ASTMA653 minimum G60 shall be formed from galvanized steelwire as specified in ASTM A641 from hot-dipped galvanized steel as specified in shall be galvanized roofing nails (type II,style 20) or galvanized common nails (type II,style 10) as specified in Fed.

10 Spec. FF-N-105B and as shown in Table 2:TABLE 2 NAILSR oofing Nails- Type II, Style 20 ShankHeadLength(in)(in)(in) 1 3/4 Common Nails- Type II, Style 10 ShankHeadLength(in)(in)(in) 1 1 1 1 for attaching METAL lath to wood sup-ports shall be in. (16ga) round or flat-tened with min. 3/4 in. crown. (see ) shall be self-drilling or self-taping asrequired in accordance with ASTM C954 orC1002. (See ) attaching METAL lath to steel framing,they shall have a 7/16 in. diameter panwafer head and a in diameter (#8)shank long enough to penetrate framinga minimum of 3/8 attaching lath to horizontal metalsupport members lath shall be attachedwith screws described above and mustcontact at least three strands of lath. Thismay require the use of 1" X 1/4" 16 ga. cut INSTALLATION, GENERALM etal lath shall be of appropriate type and weightfor the application (horizontal or vertical) and thespacing of supports as set forth in Tables 3 & 12/17/09 3:34 PM Page 2 NAAMM EMLA 920-09 METAL LATHING AND FURRING3 TABLE 3 VERTICAL ASSEMBLIES (WALLS) MAXIMUMSUPPORT SPACING, TypeLath MetalAlbs/sq yd)StudsConcreteStudsDia.