ASTM C843-99(2006)
(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 E 90, C 423, or E 492. Note 1
To ensure desirable results, coordinate this specification with Specification C 844. Note 2
General information regarding matters of a contractual nature concerning veneer plaster work is found in . Additional technical information related to veneer plastering is provided in .
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 2006)
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 Department of Defense.
1. Scope C11 TerminologyRelatingtoGypsumandRelatedBuilding
Materials and Systems
1.1 This specification covers the minimum requirements for
C423 Test Method for Sound Absorption and Sound Ab-
and methods of applying gypsum veneer plaster.
sorption Coefficients by the Reverberation Room Method
1.2 Where a specific degree of fire resistance is required for
C587 Specification for Gypsum Veneer Plaster
veneer plaster systems, applicable building code regulations
C588/C588M Specification for Gypsum Base for Veneer
shall be followed.
Plasters
1.2.1 Details of construction for a specific assembly to
C631 Specification for Bonding Compounds for Interior
achieve the required fire resistance shall be obtained from
Gypsum Plastering
reports of fire-resistance tests, engineering evaluations, or
C844 Specification for Application of Gypsum Base to
listings from recognized fire testing laboratories.
Receive Gypsum Veneer Plaster
1.3 Where a specific degree of sound control is required for
C1047 Specification forAccessories for GypsumWallboard
veneer plaster assemblies and constructions, details of con-
and Gypsum Veneer Base
struction shall be in compliance with official reports of tests
E90 Test Method for Laboratory Measurement of Airborne
conducted in recognized sound testing laboratories in accor-
Sound Transmission Loss of Building Partitions and Ele-
dance with the applicable sound tests of Test Methods E90,
ments
C423,or E492.
E492 Test Method for Laboratory Measurement of Impact
NOTE 1—To ensure desirable results, coordinate this specification with
Sound Transmission Through Floor-Ceiling Assemblies
Specification C844.
Using the Tapping Machine
NOTE 2—General information regarding matters of a contractual nature
concerning veneer plaster work is found in Appendix X1. Additional
3. Terminology
technical information related to veneer plastering is provided inAppendix
3.1 Definitions:
X2.
3.1.1 See Terminology C11.
1.4 The values stated in inch-pound units are to be regarded
3.2 Definitions of Terms Specific to This Standard:
as the standard. The values given in parentheses are for
3.2.1 base coat, n—veneer plaster trowel or machine ap-
information only.
plied as the first coat of a two-component system.
1.5 The text of this specification references notes and
3.2.2 finish coat, n—veneer finish plaster trowel or machine
footnotes which provide explanatory material. These notes and
applied as the second coat over the base coat plaster in a
footnotes (excluding those in tables and figures) shall not be
two-component system.
considered as requirements of the specification.
3.2.2.1 smooth-trowel finish, n—afinishresultingfromsteel
troweling with a minimum of water after the plaster has
2. Referenced Documents
2 become firm.Asmooth finish free of trowel marks, blemishes,
2.1 ASTM Standards:
or other imperfections.
3.2.2.2 texture finish, n—a finish resulting from (1) trowel
This specification is under the jurisdiction of ASTM Committee C11 on
applicationfollowedbyfloatingortexturingofthesurfacewith
GypsumandRelatedBuildingMaterialsandSystemsandisthedirectresponsibility
any of a variety of tools using a minimum of water or (2)
of Subcommittee C11.03 on Specifications for Application of Gypsum and Other
machine application, left as applied or followed by hand
Products in Assemblies.
Current edition approved May 1, 2006. Published May 2006. Originally texturing.
´1
approved in 1976. Last previous edition approved in 1999 as C843 – 99 . DOI:
10.1520/C0843-99R06.
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 Withdrawn. The last approved version of this historical standard is referenced
the ASTM website. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C843 – 99 (2006)
3.2.3 joint-reinforcing embedment, n—the cementitious ma- 7.6 Accessories—Specification C1047.
terial used to embed the strip material that is compatible with
the veneer plaster used.
8. Surface Preparation
3.2.4 one-component system, n—a veneer plaster system
8.1 Examination—Carefullyexamineallsurfaces,including
designed for application directly over approved bases in a
but not limited to, unit masonry, monolithic concrete, gypsum
single plaster mix applied in a single coat or double-back
bases of all types, and accessories to receive veneer plaster,
operation with the same material.
before the veneer plaster is applied. Notify the proper authori-
3.2.5 reinforced joint, n—a joint between gypsum base that
ties promptly of all unsatisfactory conditions. The examination
is reinforced with strip material embedded in a cementitious
shall determine whether the gypsum base has been exposed to
material.
excessive sunlight. Do not apply veneer plaster until after such
3.2.6 reinforcing, n—joint reinforcing tape or mesh (strip
unsatisfactory conditions are rectified to the satisfaction of the
material) that is applied over flat joints and interior angles.
plastering contractor.
3.2.7 two-component system, n—a veneer plaster system
NOTE 4—The bond of alkaline veneer plaster to gypsum base may be
involving two separate materials mixed and applied separately
impaired if the base is exposed to direct light or sunlight for extended
for base coat and finish coat.
periods.
3.2.8 veneer plaster system, n—gypsum veneer plaster ap-
8.1.1 Do not apply veneer plaster over any surfaces of unit
plied to (1) a gypsum base in accordance with 10.1 or (2)
masonry or concrete that have been coated with any bitumi-
properly prepared masonry or monolithic concrete surfaces,
nouscompoundorotherwaterproofingordamproofingorform
neither side of which is exposed to moisture. The plaster shall
release agent.
be applied with one or more components not exceeding ⁄4 in.
8.2 Conditioning of Surfaces:
(6.4 mm) in total thickness.
8.2.1 Immediately before the plaster is applied, wet down
4. Delivery of Materials
the masonry surfaces on which suction shall be reduced.
Visible water shall not remain on the surface.
4.1 All manufactured materials shall be delivered in the
original packages, containers, or cartons bearing the brand 8.2.2 Carefully examine accessories, such as corner beads,
control joints, casing beads, etc., to ensure that they are
name and manufacturer identification.
straight, curved, plumb, level, square, or true to the required
5. Protection of Materials
angles and have been applied in a manner to ensure full
5.1 Plasters and other cementitious materials shall be kept
coverage of flanges before the plaster is applied.
dry until ready to be used; they shall be kept off the ground,
8.3 Monolithic Concrete Surfaces—Clean monolithic con-
under cover, and away from damp walls and surfaces.
crete surfaces of all dust, loose particles, and other foreign
matter. Completely remove all grease, oil, noncompatible
6. Environmental Conditions
curing compounds, and form releasing agents. Remove all
6.1 Temperature—When the ambient outside temperature at 1
ridges and protrusions greater that ⁄8 in. (3.2 mm) and fill all
the building site is less than 55 °F (13 °C), maintain a 1
depressions greater than ⁄4 in. (6.4 mm) level with portland
temperatureinthebuildingofnotlessthan55°F(13°C)ornot
cement mortar and allow to set and dry. Any further prepara-
more than 80 °F (27 °C) for not less than 24 h prior to the
tion shall be as recommended by the veneer plaster manufac-
application of veneer plaster and for one week after the veneer
turer.
plaster has set or until the veneer plaster has dried. Distribute
8.4 Gypsum Base Joint Reinforcement—Reinforce all inte-
heat evenly in all work areas, and use deflection or protective
rior angles and flat joints prior to application of the veneer
screens to prevent concentrated or uneven heat or cold on the
plaster over the base.
veneer plaster.
8.4.1 Interior Angles—Position and secure reinforcement
with staples (on 12-in. (305-mm) centers, one side only),
NOTE 3—The requirements in 6.1 will minimize the cracking of veneer
veneer plaster, or other cementitious material compatible with
plaster due to structural movements caused by thermal changes from
temperature extremes; and dry-outs due to hot spots caused by concen- the veneer plaster or by using self-adhering strip reinforce-
trated heat.
ment. When stapling, staple along the ceiling edge only for
wall-to-ceiling angles and along one edge for wall-to-wall
6.2 Ventilation—Ventilation shall be provided to remove
angles. When securing reinforcement with veneer plaster,
excess water given off through the drying process.
reinforcement shall be thoroughly embedded so that embed-
7. Materials
ment material is both under and covering reinforcement.
7.1 Gypsum Base for Veneer Plasters (hereinafter referred 8.4.2 Flat Joints—Center reinforcement over the joint line
to as “gypsum base”) Specification C588/C588M. of the gypsum base and secure with staples or veneer plaster if
7.2 Veneer Plasters—Specification C587. not using self-adhering reinforcement. Keep reinforcement
7.3 Reinforcing—Noncorrosive strip providing the joint tight and flat against the gypsum base, and when stapling,
strength requirements of Specification C587. position the staples no farther than 24 in. (610 mm) apart,
7.4 Liquid Bonding Compounds—Specification C631 (see staggered along each edge. Embed reinforcement and continue
X2.3). application of the veneer plaster over the field of the base.
7.5 Water—Watershallbeclean,fresh,andofpotablewater (Warning—This method provides minimum reinforcement of
quality. the joints. To minimize incidence and severity of joint ridging
C843 – 99 (2006)
and cracking, use one of the following methods (8.4.2.1, 9.2.1 Donotusegauging,molding,orcastingplasters,lime,
8.4.2.2,or 8.4.2.3) in the absence of any specific method gypsum, Keene’s cement, portland cement, etc. to adjust the
recommendedbytheveneerplastermanufacturer.Wherepaper
veneer plaster setting time.
tape and setting-type joint compounds are used, use 8.4.2.3.)
9.3 Occasionally, special textures are desired that require
8.4.2.1 Reinforcement over Set Veneer Plaster—Tightly
additional
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