ASTM C841-03(2013)
(Specification)Standard Specification for Installation of Interior Lathing and Furring
Standard Specification for Installation of Interior Lathing and Furring
ABSTRACT
This specification covers the minimum requirements for, and the methods of application of, interior lathing and furring to receive gypsum plaster applied. Other materials are not prohibited from being used provided that their physical characteristics and durability under conditions of usage are at least equal in performance to those described. All materials shall be kept dry, preferably by being stored inside. Where necessary to be stored outside, materials shall be stacked off the ground, supported on a level platform, and protected from the weather and surface contamination. Materials shall be neatly stacked flat with care taken to avoid damage to edges, ends, or surfaces. The materials to be used are the following: tie wire and hanger wire, gypsum lath, expanded metal lath, welded wire lath, woven wire lath, nails, screws, staples, paper, and accessories such as control joints, cornerite, channels, rod and flat hangers, clips, and striplath. In general, during installation, the following shall be required: application of gypsum lath to supports, application of gypsum lath to wood supports, application of gypsum lath to metal supports, studless solid partitions (gypsum lath and plaster), application of metal plaster bases to framing members, studless solid partitions (metal lath and plaster), suspended and furred ceilings (metal lath and gypsum lath construction), main runners, cross furring, and metal furring for walls.
SCOPE
1.1 This specification covers the minimum requirements for, and the methods of application of, interior lathing and furring to receive gypsum plaster applied in accordance with Specification C842. Other materials are not prohibited from being used provided that their physical characteristics and durability under conditions of usage are at least equal in performance to those described.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 Details of construction for a specific assembly to achieve the required fire resistance shall be obtained from reports of fire-resistance tests, engineering evaluations, or listings from recognized fire testing laboratories.
1.4 Where a specific degree of sound control is required for plastered assemblies and constructions, details of construction shall be obtained from reports of sound tests of assemblies that have met the requirements of Test Method E492.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:C841 −03 (Reapproved 2013)
Standard Specification for
Installation of Interior Lathing and Furring
This standard is issued under the fixed designation C841; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope C514 Specification for Nails for the Application of Gypsum
Board
1.1 Thisspecificationcoverstheminimumrequirementsfor,
C754 Specification for Installation of Steel Framing Mem-
and the methods of application of, interior lathing and furring
bers to Receive Screw-Attached Gypsum Panel Products
to receive gypsum plaster applied in accordance with Specifi-
C842 Specification forApplication of Interior Gypsum Plas-
cation C842. Other materials are not prohibited from being
ter
used provided that their physical characteristics and durability
C847 Specification for Metal Lath
under conditions of usage are at least equal in performance to
C933 Specification for Welded Wire Lath
those described.
C954 SpecificationforSteelDrillScrewsfortheApplication
1.2 The values stated in inch-pound units are to be regarded
of Gypsum Panel Products or Metal Plaster Bases to Steel
as standard. The values given in parentheses are mathematical
Studs from 0.033 in. (0.84 mm) to 0.112 in. (2.84 mm) in
conversions to SI units that are provided for information only
Thickness
and are not considered standard.
C1002 Specification for Steel Self-Piercing Tapping Screws
1.3 Details of construction for a specific assembly to for Application of Gypsum Panel Products or Metal
achieve the required fire resistance shall be obtained from
Plaster Bases to Wood Studs or Steel Studs
reports of fire-resistance tests, engineering evaluations, or
C1007 Specification for Installation of Load Bearing (Trans-
listings from recognized fire testing laboratories.
verse and Axial) Steel Studs and Related Accessories
C1032 Specification for Woven Wire Plaster Base
1.4 Where a specific degree of sound control is required for
D1784 Specification for Rigid Poly(Vinyl Chloride) (PVC)
plastered assemblies and constructions, details of construction
Compounds and Chlorinated Poly(Vinyl Chloride)
shall be obtained from reports of sound tests of assemblies that
(CPVC) Compounds
have met the requirements of Test Method E492.
D3678 Specification for Rigid Poly(Vinyl Chloride) (PVC)
Interior-Profile Extrusions
2. Referenced Documents
E492 Test Method for Laboratory Measurement of Impact
2.1 ASTM Standards:
Sound Transmission Through Floor-Ceiling Assemblies
A641/A641M Specification for Zinc–Coated (Galvanized)
Using the Tapping Machine
Carbon Steel Wire
2.2 National Association of Architectural Metal Manufac-
C11 Terminology Relating to Gypsum and Related Building
turers Standard
Materials and Systems
HMMA 840 Installation and Storage of Hollow Metal Doors
C37/C37M Specification for Gypsum Lath (Withdrawn
and Frames
2004)
3. Terminology
This specification is under the jurisdiction of ASTM Committee C11 on
3.1 Definitions—For definitions relating to ceilings and
Gypsum and Related Building Materials and Systems and is the direct responsibility
walls see Terminology C11.
ofSubcommitteeC11.03onSpecificationsfortheApplicationofGypsumandOther
3.2 Definitions of Terms Specific to This Standard:
Products in Assemblies.
Current edition approved Oct. 1, 2013. Published October 2013. Originally
3.2.1 base coat, n—the sum of the scratch and brown coats
approved in 1976. Last previous edition approved in 2008 as C841 – 03 (2008)ε1.
or the total coats in place prior to application of finish coats.
DOI: 10.1520/C0841-03R13.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Available from National Association of Architectural Metal Manufacturers
The last approved version of this historical standard is referenced on (NAAMM), 800 Roosevelt Road, Bldg. C, Suite 312, Glen Ellyn, IL 60137,
www.astm.org. http://www.naamm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C841−03 (2013)
3.2.2 contact ceiling, n—a ceiling in which the lath is
Wire Gage (U.S. Steel
A
Diameter, in. (mm) Wire Gage)
attached in direct contact with the construction above, without
0.0800 (2.03) No. 14
the use of main runners or cross furring.
0.0915 (2.32) No. 13
3.2.3 furred ceiling, n—a ceiling in which the furring used
0.1055 (2.68) No. 12
0.1205 (3.06) No. 11
for the support of the lath is attached directly to the structural
0.1350 (3.43) No. 10
members of the building.
0.1483 (3.77) No. 9
0.1620 (4.11) No. 8
3.2.4 suspended ceiling, n—a ceiling in which the main
_____________
runners and cross furring are suspended below the structural
A
Allowable variations in diameter shall be in accordance with tolerances as
members of the building.
established in A641/A641M.
3.2.5 main runners, n—the members that are attached to or
6.2 Gypsum Lath—Specification C37/C37M.
suspended from the construction above for the support of cross
furring.
6.3 Expanded Metal Lath—Specification C847.
3.2.6 cross furring, n—furring members that are attached at
6.4 Wire Lath:
right angles to the underside of the main runners or construc-
6.4.1 Welded Wire Lath, Specification C933.
tion above for support of the lath.
6.4.2 Woven Wire Lath, Specification C1032.
3.2.7 furring, n—spacer strips fastened to a wall, ceiling, or
planarelementthatcreateanevensurfacefortheapplicationof
6.5 Fasteners:
metal plaster bases or gypsum lath.
6.5.1 Nails for Attaching Gypsum Lath—Specification
3.2.8 primary members, n—the members (main runners or C514. Nail size shall be in accordance with Table 1.
structural supports) to which the cross furring is attached.
6.5.2 Nails for Attaching Metal Plaster Base—Galvanized
roofing nails or common nails. length shall be as specified in 7.
3.2.9 metal plaster bases, n—expanded metal lath, sheet
metal lath, welded or woven wire lath.
6.5.3 Screws—Specifications C954 or C1002.
3.2.10 face side (gypsum lath), n—the side opposite the 6.5.3.1 Screws for attaching gypsum lath shall be sized in
paper cover seam laps. accordance with Table 1.
6.5.3.2 Screws for attaching metal plaster base shall have a
3.2.11 surface transition, n—the change in width of a
⁄16 in. (11.1 mm) diameter pan washer head and a 0.120 in.
surface, usually as a result of penetrations (doors, windows) or
(3.0 mm) diameter shank.The length shall be sufficient enough
architectural demands.
toallowforthethreadedportionofthescrewtoprojectnotless
4. Delivery of Materials than ⁄8 in. (9.5 mm) through steel framing when the lath is
installed.
4.1 All materials shall be delivered in the original packages,
6.5.4 Staples—Staples for attaching gypsum lath shall con-
containers, or bundles bearing the brand name and manufac-
form to the requirements of Table 1.
turer’s (or supplier’s) identification.
6.5.4.1 Staples for attaching metal plaster base shall be
5. Storage of Materials
0.062 in. (1.6 mm) diameter, round or flattened steel wire with
⁄4 in. (19.0 mm) crown. Lengths shall be as specified for
5.1 All materials shall be kept dry, preferably by being
individual systems.
stored inside. Where necessary to be stored outside, materials
shall be stacked off the ground, supported on a level platform,
6.6 Paper or Other Backing—When used on metal plaster
and protected from the weather and surface contamination.
bases, over solid backing, backing shall be securely held in
5.2 Materials shall be neatly stacked flat with care taken to place by, or attached to the metal plaster base. Metal plaster
base shall allow for ⁄4 in. (6.4 mm) self furring. The backing
avoid damage to edges, ends, or surfaces.
shall permit embedment of plaster.
6. Materials
6.7 Accessories—Shall be steel, coated, with a protective
6.1 Wire Specification A641/A641M, Class 1 coating (gal-
rust inhibitive coating after fabrication, or fabricated from
vanized) soft temper.
zinc-coated (galvanized) steel, aluminum, zinc alloy, or high
6.1.1 Tie Wire and Hanger Wire—Zinc-coated (galvanized)
impact plastic. Plastic accessories shall be nmanufactured in
soft-annealed steel, or a material having equivalent size,
accordance with Specifcation D1784 or Specification D3678.
corrosion resistance and strength. Wire diameters (uncoated)
Aluminum accessories shall be clear plastic coated. All acces-
specified herein correspond with United States steel wire gage
soriesshallhaveperforatedorexpandedflangesorclipsshaped
numbers as follows:
so as to permit complete imbedment in the plaster, to provide
means for secure alignment, and to secure attachment of the
Wire Gage (U.S. Steel
A
Diameter, in. (mm) Wire Gage)
accessory to the underlying surface. Accessories shall be
0.0348 (0.88) No. 20
designed for the intended use and to receive or to permit
0.0410 (1.04) No. 19
application of the specified plaster thickness.
0.0475 (1.21) No. 18
0.0540 (1.37) No. 17
6.7.1 Thickness of base material for accessories shall be not
0.0625 (1.59) No. 16
less than as shown in the following:
C841−03 (2013)
A,B
TABLE 1 Screws, Nails and Staples for Attaching Gypsum Lath to Horizontal and Vertical Wood Supports
Maximum Spacing, in. (mm) Minimum Gage Requirements, in. (mm)
Diameter of
Flat Head or Gage of
Distance Number of Approximate Depth of
Width of Thickness Length of Blued Nails Shank of
Between Attachments Spacing c to c of Support
Lath of Lath Leg or Crown Nails or
Supports per Bearing Attachments Penetration
A
Width of Staples
A
Staples
3 1 3 19
16 (406) ⁄8 (9.5) 16 (406) 4 5 (127) 1 ⁄8 (28.6) ⁄4 (19) ⁄64 (7.5) 13
A A A A
5 7
1 (25.4) ⁄8 (15.9) ⁄16 (11) 16
3 1 1 3 19
24 (610) ⁄8 (9.5) 16 (406) 6 4 ⁄2 (114) 1 ⁄8 (28.6) ⁄4 (19) ⁄64 (7.5) 13
A A A A
5 7
1 (25.4) ⁄8 (15.9) ⁄16 (11) 16
1 1 3 19
16 (406) ⁄2 (12.7) 24 (610) 4 5 (127) 1 ⁄4 (32) ⁄4 (19) ⁄64 (7.5) 13
A A A A
1 5 7
1 ⁄8 (28.6) ⁄8 (15.9) ⁄16 (11) 16
1 1 1 3 19
24 (610) ⁄2 (12.7) 24 (610) 6 4 ⁄2 (114) 1 ⁄4 (32) ⁄4 (19) ⁄64 (7.5) 13 (330)
A A A A
1 5 7
1 ⁄8 (28.6) ⁄8 (15.9) ⁄16 (11) 16
3 1 1 3
48 (1219) ⁄8 (9.5) 16 (406) 8 4 ⁄2 (114) 1 ⁄8 (28.6) ⁄4 (19)
A A
1 5
⁄2 (12.7) 24 (610) 1 (25.4) ⁄8 (15.9)
1 3
1 ⁄4 (32) ⁄4 (19)
A A
1 5
1 ⁄8 (28.6) ⁄8 (15.9)
A
Galvanized staples.
B
Screws for attaching gypsum lath to wood supports shall be Type W as described in Specification C1002.
6.7.7 Striplath—Shall be not less than 1.75 lb/yd (0.85
Base Material (mm) Thickness of
Base Material, in.
kg/m ) expanded metal lath, or woven or welded fabric of not
Uncoated steel/zinc 0.014 (0.36)
less than 0.041 in. (1.04 mm) thick weighing not less than 1.75
PVC 0.030 (0.76)
2 2
lb/yd (0.85 kg/m ) fabricated from galvanized steel.
Aluminum 0.050 (1.27)
6.7.2 Control Joints—Shall be formed by using a single
7. Installation
prefabricated member or fabricated by installing casing beads
7.1 General Requirements for Application of Lath and
back to back with a flexible barrier membrane behind casing
Accessories:
beads. The separation spacing shall be not less than ⁄8 in. (3.2
7.1.1 Lath shall be installed with the long dimension at right
mm) or as required by the anticipated thermal exposure range.
angles to supports, unless otherwise specified.
6.7.3 Cornerite—shall be not less than 1.75 lb/yd (0.85
7.1.2 Corner beads shall be installed to protect all external
kg/m ) expanded metal lath, galvanized, or given a protective
corners and to establish grounds. Corner beads shall be
coating of rust inhibitive paint after fabrication, or woven or
attached to the substrate in such a manner as to ensure proper
welded fabric not less than 0.041 in. (1.04 mm) thick an
2 2
alignment during application of plaster.
weighing not less than 1.75 lb/yd (0.85 kg/m ), fabricated
7.1.3 Metal accessories shall be installed so that flanges and
from galvanized wire. When shaped for angle reinforcing,
clipsprovidedfortheirattachmentarecoveredbythebasecoat
cornerite shall have outstanding legs of not less than 2 in. (50.8
plaster.
mm).
7.1.4 Control Joints—Shall be installed in ceilings greater
6.7.4 Channels—Shall be cold-rolled steel, free of rust with
2 2
than 2500 ft (232 m ) in area and in partition, wall, and wall
a coating of rust inhibitive paint or galvanized. Channels used
furring runs greater than 30 ft (9 m) in length. The distance
in areas subject to corrosive action of salt air or other corrosive
between ceiling control joints shall not be more than 50 ft (15
environments, shall be hot-dip galvanized. Weight of the
m) in either direction. A control joint shall be installed where
channel shall be not less than as shown in the following:
the ceiling framing or furring changes direction. The distance
Size Weight
betweencontroljointsinwallsorwallfurringshallbenotmore
in. (mm) lb/1000 lf (kg/m)
⁄4 (19) 277 (0.412)
than 30 ft (9 m). A control joint shall be installed where an
1 ⁄2 (38) 414 (0.616)
expansion joint occurs in the base exterior wall or ceiling. A
2 (50) 506 (0.753)
ceiling height door frame, installed in accordance with the
2 ⁄2 (64) 597 (0.888)
spacing requirements set forth in this section, is not prohibited
6.7.5 Rod and flat (strap) hangers shall be mild steel, zinc from being used as a control joint.
coated or protected with a rust-inhibiting paint. 7.1.5 Where partition assemblies require the installation of
6.7.6 Clips—Devices for attaching framing members to control joints over the head of door frames to relieve stresses
supports or to each other; for attaching lath to framing within the assemblies, such control joints shall be installed in
members; or for securing lath to lath, shall be formed of the following manner:
zinc-coated (galvanized) steel wire or sheet, and of sufficient 7.1.5.1 Wherecontroljointsarelocatedattheverticalcenter
size and strength to support the intended load of the door opening two metal studs shall be installed not more
C841−03 (2013)
than ⁄2 in. (12.7 mm) apart over the center of the span at the 7.4 Application of Gypsum Lath to Metal Supports:
head of the frame, with the lath installed so that a vertical joint 7.4.1 Gypsum lath shall be attached to horizontal or vertical
occurs between the studs. A prefabricated control joint or metal supports with staples, screws, or nails, or
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.