ASTM C1764-20

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Designation: C1764 − 12 (Reapproved 2018) C1764 − 20
Standard Test Methods for
Non Metallic Plaster Bases (Lath) Used withWith Portland
Cement Based Plaster in Vertical Wall Applications
This standard is issued under the fixed designation C1764; 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.
1. Scope
1.1 These test methods evaluate the performance of vertical wall applications of non metallic plaster bases used with Portland
Cement Based Plastercement based plaster under a variety of test exposures.
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in
each system mayare not benecessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be
used independently of the other. Combiningother, and values from the two systems may result in non-conformance with the
standard.shall not be combined.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C926 Specification for Application of Portland Cement-Based Plaster
E330/E330M Test Method for Structural Performance of Exterior Windows, Doors, Skylights and Curtain Walls by Uniform
Static Air Pressure Difference
E631 Terminology of Building Constructions
E2098/E2098M Test Method for Determining Tensile Breaking Strength of Glass Fiber Reinforcing Mesh for Use in Class PB
Exterior Insulation and Finish Systems (EIFS), after Exposure to a Sodium Hydroxide Solution
2.2 ICC-ES Acceptance Criteria:
AC 191 Acceptance Criteria for Metal Plaster Bases (Lath)
3. Terminology
3.1 Definitions—For definitions of terms used in these test methods, refer to Terminology E631.
These test methods are under the jurisdiction of ASTM Committee C11 on Gypsum and Related Building Materials and Systems and is the direct responsibility of
Subcommittee C11.02 on Specifications and Test Methods for Accessories and Related Products.
Current edition approved Oct. 1, 2018Oct. 15, 2020. Published October 2018November 2020. Originally approved in 2012. Last previous edition approved in 20162018
as C1764 – 12 (2016).(2018). DOI: 10.1520/C1764-12R18.10.1520/C1764-20.
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.
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C1764 − 20
3.1 Definitions:
3.1.1 For definitions of terms used in these test methods, refer to Terminology E631.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 non metallic, plaster base (lath)—material used a product manufactured from non metal materials that serves as a base for
Portland Cement Based Plaster that is flat or self furred.cement based plaster.
3.2.1.1 Discussion—
Examples of non metallic materials are plastic, glass fiber, and nylon
4. Significance and Use
4.1 General:
4.1.1 Non metallic reinforced Portland Cement Based Plastercement based plaster are vertically applied exterior wall claddings
that may be subject to variety of conditions over the claddings service life. The series of tests described in this standard evaluates
These test methods evaluate performance under a variety of test conditions and exposures. Any given project may not be subject
to all of the test conditions described herein and all of the test methods may not evaluate all exposures for a given project.
4.2 Transverse Load:
4.2.1 This test method determines the ultimate wind load resistance of the wall assembly including influence of the framing,
sheathing, and means of attachment.
4.3 Vertical Load:
4.3.1 The weight and attachment mechanism of Portland Cementcement Based Plaster results in a vertical load transfer to the
plaster base. This test method determines the ultimate vertical load capacity of the cladding assembly based on taking the specimen
to failure.
4.4 Embedment:
4.4.1 Plaster bases serve as a key, reinforcement and attachment mechanism for Portland Cement Based Plaster.cement based
plaster. The thickness, profile, and material properties of the plaster bases must be such that it is adequately embedded in the
Portland Cement Based Plaster.cement based plaster. This can be accomplished through use of a self furred non metallic plaster
base or other means such as furring strips. This test proceduremethod determines the effectiveness of the furring mechanism to
ensure that the minimum embedment is obtained.
4.5 Fastener Pull Through Resistance:
4.5.1 The non metallic lath is secured to the building frame or substrate with fasteners. This test method evaluates the fastener
attachment effectiveness.
4.6 Alkali Resistance (Glass Fiber Lath(Test Method Applies to Glass Fiber Materials Only):
4.6.1 Per In accordance with Test Method E2098/E2098M.
5. Sampling, Test Specimens, and Test Units
5.1 The number, size and configuration of the test specimens shall be as per in accordance with each test proceduremethod, with
the exception of Transverse Load tests which shall incorporate wood or steel framing as determined by the user. Samples shall be
representative of standard products and construction methods.
6. Test Specimens
6.1 Transverse Load:
C1764 − 20
6.1.1 Construct three test specimens. Test specimen size shall be minimum 4 by 8 ft (1.2 by 2.4 m) and constructed representative
of end use conditions. Framing members shall be wood or steel as determined by the user. Specification C926 Portland Cement
Based Plastercement based plaster shall be mixed and applied in the configuration of the test specimen.
6.2 Vertical Load:
6.2.1 Construct three test frames measuring 12 by 20 in. (305 by 508 mm) using nominal 2 by 4 in. (50 by 100 mm) wood lumber
with specific gravity of 0.42. The test frame shall have one intermediate stud with top and bottom plates and sheathed one side
1 1
with ⁄2 in. (13 mm) thick gypsum sheathing. Attach studs to plates using 2two 16d (3 ⁄2 in. (89 mm) length) nails and sheathing
to framing using 6d (2 in. length) common nails or equal fastened 8 in. (200 mm) on center. A test panel shall be prepared
measuring 6 in. (152 mm) high by 16 in. (406 mm) (406 mm) wide and consisting of a water-resistive barrier (provided to prevent
adhesion of the test panel to the test frame); non metallic plaster base, which is attached through the water-resi
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