ASTM C843-99(2012)
(Specification)Standard Specification for Application of Gypsum Veneer Plaster
Standard Specification for Application of Gypsum Veneer Plaster
ABSTRACT
This specification covers the minimum requirements for gypsum veneer plaster and includes application methods on systems such as electric heat cable systems but not exceeding a specified temperature. Applicable building code regulations should be followed when a specific degree of fire resistance is required. Plaster and other cementitious materials should be kept dry until these are ready to be used and should be kept off the ground, under cover, and away from damp walls and surfaces.
SCOPE
1.1 This specification covers the minimum requirements for and methods of applying gypsum veneer plaster.
1.2 Where a specific degree of fire resistance is required for veneer plaster systems, applicable building code regulations shall be followed.
1.2.1 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.
1.3 Where a specific degree of sound control is required for veneer plaster assemblies and constructions, details of construction shall be in compliance with official reports of tests conducted in recognized sound testing laboratories in accordance with the applicable sound tests of Test Methods E90, C423, or E492.
Note 1—To ensure desirable results, coordinate this specification with Specification C844.
Note 2—General information regarding matters of a contractual nature concerning veneer plaster work is found in Appendix X1. Additional technical information related to veneer plastering is provided in Appendix X2.
1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.
General Information
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C843 −99 (Reapproved 2012)
Standard Specification for
Application of Gypsum Veneer Plaster
This standard is issued under the fixed designation C843; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This specification covers the minimum requirements for
C11 Terminology Relating to Gypsum and Related Building
and methods of applying gypsum veneer plaster.
Materials and Systems
1.2 Where a specific degree of fire resistance is required for
C423 Test Method for SoundAbsorption and SoundAbsorp-
veneer plaster systems, applicable building code regulations
tion Coefficients by the Reverberation Room Method
shall be followed.
C587 Specification for Gypsum Veneer Plaster
1.2.1 Details of construction for a specific assembly to
C588/C588M Specification for Gypsum Base for Veneer
achieve the required fire resistance shall be obtained from
Plasters (Withdrawn 2005)
reports of fire-resistance tests, engineering evaluations, or
C631 Specification for Bonding Compounds for Interior
listings from recognized fire testing laboratories.
Gypsum Plastering
C844 Specification for Application of Gypsum Base to
1.3 Where a specific degree of sound control is required for
Receive Gypsum Veneer Plaster
veneer plaster assemblies and constructions, details of con-
C1047 Specification for Accessories for Gypsum Wallboard
struction shall be in compliance with official reports of tests
and Gypsum Veneer Base
conducted in recognized sound testing laboratories in accor-
E90 Test Method for Laboratory Measurement of Airborne
dance with the applicable sound tests of Test Methods E90,
Sound Transmission Loss of Building Partitions and
C423,or E492.
Elements
NOTE 1—To ensure desirable results, coordinate this specification with
E492 Test Method for Laboratory Measurement of Impact
Specification C844.
Sound Transmission Through Floor-Ceiling Assemblies
NOTE 2—General information regarding matters of a contractual nature
Using the Tapping Machine
concerning veneer plaster work is found in Appendix X1. Additional
technical information related to veneer plastering is provided in Appendix
3. Terminology
X2.
3.1 Definitions:
1.4 The values stated in inch-pound units are to be regarded
3.1.1 See Terminology C11.
as the standard. The values given in parentheses are for
3.2 Definitions of Terms Specific to This Standard:
information only.
3.2.1 base coat, n—veneer plaster trowel or machine ap-
plied as the first coat of a two-component system.
1.5 The text of this specification references notes and
footnotes which provide explanatory material. These notes and 3.2.2 finish coat, n—veneer finish plaster trowel or machine
footnotes (excluding those in tables and figures) shall not be applied as the second coat over the base coat plaster in a
considered as requirements of the specification. two-component system.
3.2.2.1 smooth-trowel finish, n—a finish resulting from steel
troweling with a minimum of water after the plaster has
This specification is under the jurisdiction of ASTM Committee C11 on
GypsumandRelatedBuildingMaterialsandSystemsandisthedirectresponsibility For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ofSubcommitteeC11.03onSpecificationsfortheApplicationofGypsumandOther contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Products in Assemblies. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved March 1, 2012. Published June 2012. Originally the ASTM website.
approved in 1976. Last previous edition approved in 2006 as C843–99 (2006). DOI: The last approved version of this historical standard is referenced on
10.1520/C0843-99R12. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C843−99 (2012)
become firm.Asmooth finish free of trowel marks, blemishes, 7. Materials
or other imperfections.
7.1 Gypsum Base for Veneer Plasters (hereinafter referred
3.2.2.2 texture finish, n—a finish resulting from (1) trowel to as “gypsum base”) Specification C588/C588M.
applicationfollowedbyfloatingortexturingofthesurfacewith
7.2 Veneer Plasters—Specification C587.
any of a variety of tools using a minimum of water or (2)
7.3 Reinforcing—Noncorrosive strip providing the joint
machine application, left as applied or followed by hand
strength requirements of Specification C587.
texturing.
7.4 Liquid Bonding Compounds—Specification C631 (see
3.2.3 joint-reinforcing embedment, n—the cementitious ma-
X2.3).
terial used to embed the strip material that is compatible with
the veneer plaster used.
7.5 Water—Water shall be clean, fresh, and of potable water
quality.
3.2.4 one-component system, n—a veneer plaster system
designed for application directly over approved bases in a
7.6 Accessories—Specification C1047.
single plaster mix applied in a single coat or double-back
operation with the same material.
8. Surface Preparation
3.2.5 reinforced joint, n—a joint between gypsum base that
8.1 Examination—Carefully examine all surfaces, including
is reinforced with strip material embedded in a cementitious
but not limited to, unit masonry, monolithic concrete, gypsum
material.
bases of all types, and accessories to receive veneer plaster,
before the veneer plaster is applied. Notify the proper authori-
3.2.6 reinforcing, n—joint reinforcing tape or mesh (strip
ties promptly of all unsatisfactory conditions. The examination
material) that is applied over flat joints and interior angles.
shall determine whether the gypsum base has been exposed to
3.2.7 two-component system, n—a veneer plaster system
excessive sunlight. Do not apply veneer plaster until after such
involving two separate materials mixed and applied separately
unsatisfactory conditions are rectified to the satisfaction of the
for base coat and finish coat.
plastering contractor.
3.2.8 veneer plaster system, n—gypsum veneer plaster ap-
NOTE 4—The bond of alkaline veneer plaster to gypsum base may be
plied to (1) a gypsum base in accordance with 10.1 or (2)
impaired if the base is exposed to direct light or sunlight for extended
properly prepared masonry or monolithic concrete surfaces,
periods.
neither side of which is exposed to moisture. The plaster shall
8.1.1 Do not apply veneer plaster over any surfaces of unit
be applied with one or more components not exceeding ⁄4 in.
masonry or concrete that have been coated with any bitumi-
(6.4 mm) in total thickness.
nouscompoundorotherwaterproofingordamproofingorform
release agent.
4. Delivery of Materials
8.2 Conditioning of Surfaces:
4.1 All manufactured materials shall be delivered in the
8.2.1 Immediately before the plaster is applied, wet down
original packages, containers, or cartons bearing the brand
the masonry surfaces on which suction shall be reduced.
name and manufacturer identification.
Visible water shall not remain on the surface.
8.2.2 Carefully examine accessories, such as corner beads,
5. Protection of Materials
control joints, casing beads, etc., to ensure that they are
5.1 Plasters and other cementitious materials shall be kept
straight, curved, plumb, level, square, or true to the required
dry until ready to be used; they shall be kept off the ground,
angles and have been applied in a manner to ensure full
under cover, and away from damp walls and surfaces.
coverage of flanges before the plaster is applied.
8.3 Monolithic Concrete Surfaces—Clean monolithic con-
6. Environmental Conditions
crete surfaces of all dust, loose particles, and other foreign
matter. Completely remove all grease, oil, noncompatible
6.1 Temperature—When the ambient outside temperature at
curing compounds, and form releasing agents. Remove all
the building site is less than 55 °F (13 °C), maintain a
ridges and protrusions greater that ⁄8 in. (3.2 mm) and fill all
temperatureinthebuildingofnotlessthan55°F(13°C)ornot
more than 80 °F (27 °C) for not less than 24 h prior to the depressions greater than ⁄4 in. (6.4 mm) level with portland
cement mortar and allow to set and dry. Any further prepara-
application of veneer plaster and for one week after the veneer
plaster has set or until the veneer plaster has dried. Distribute tion shall be as recommended by the veneer plaster manufac-
turer.
heat evenly in all work areas, and use deflection or protective
screens to prevent concentrated or uneven heat or cold on the
8.4 Gypsum Base Joint Reinforcement—Reinforce all inte-
veneer plaster.
rior angles and flat joints prior to application of the veneer
plaster over the base.
NOTE 3—The requirements in 6.1 will minimize the cracking of veneer
plaster due to structural movements caused by thermal changes from 8.4.1 Interior Angles—Position and secure reinforcement
temperature extremes; and dry-outs due to hot spots caused by concen-
with staples (on 12-in. (305-mm) centers, one side only),
trated heat.
veneer plaster, or other cementitious material compatible with
6.2 Ventilation—Ventilation shall be provided to remove the veneer plaster or by using self-adhering strip reinforce-
excess water given off through the drying process. ment. When stapling, staple along the ceiling edge only for
C843−99 (2012)
wall-to-ceiling angles and along one edge for wall-to-wall veneer plaster products. In the absence of explicit directions,
angles. When securing reinforcement with veneer plaster, follow the recommendations in X2.1.
reinforcement shall be thoroughly embedded so that embed-
9.2 Setting Time—Setting times are carefully controlled by
ment material is both under and covering reinforcement.
the manufacturer. Do not make adjustments to the setting time
8.4.2 Flat Joints—Center reinforcement over the joint line
on the job. If problems with setting develop under unusual job
of the gypsum base and secure with staples or veneer plaster if
conditions, consult the manufacturer of the veneer plaster for
not using self-adhering reinforcement. Keep reinforcement
recommendations.
tight and flat against the gypsum base, and when stapling,
9.2.1 Donotusegauging,molding,orcastingplasters,lime,
position the staples no farther than 24 in. (610 mm) apart,
gypsum, Keene’s cement, portland cement, etc. to adjust the
staggered along each edge. Embed reinforcement and continue
veneer plaster setting time.
application of the veneer plaster over the field of the base.
9.3 Occasionally, special textures are desired that require
(Warning—This method provides minimum reinforcement of
additional sand. Approval of the veneer plaster manufacturer
the joints. To mi
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