ASTM C926-15a

Standard Specification for Application of Portland Cement-Based Plaster

ABSTRACT
This specification covers the standard requirements for the application of full thickness Portland cement-based plaster for exterior (stucco) and interior work. It also sets forth tables for proportioning of various plaster mixes and plaster thickness. The materials used shall consist of the following: cement which shall be a Portland cement, air-entraining Portland cement, masonry cement, blended hydraulic cement, air-entraining blended hydraulic cement, or plastic cement; Type S hydrated lime; aggregates such as perlite and sand for base and job-mixed finish coats; water to be used in mixing; admixtures; and fibers. Surfaces of solid bases such as masonry, stone, cast-in-place or precast concrete shall be prepared either by sandblasting, wire brushing, acid etching, chipping, or a combination thereof. Details on curing to resist cracking; materials protection and storage; environmental conditions; and application of plaster, finish-coat, and fog-coat, which shall be done by hand or machine up to the specified nominal thickness on metal and solid plaster bases are discussed.
SCOPE
1.1 This specification covers the requirements for the application of full thickness portland cement-based plaster for exterior (stucco) and interior work.  
1.2 This specification sets forth tables for proportioning of various plaster mixes and plaster thickness.  
Note 1: General information will be found in Annex A1. Design considerations will be found in Annex A2.  
1.3 The values stated in inch-pound units are to be regarded as the standard. The SI (metric) values given in parentheses are approximate and are provided for information purposes only.  
1.4 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.  
1.5 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.

General Information

• Status: Historical
• Publication Date: 31-May-2015
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.03 - Specifications for the Application of Gypsum and Other Products in Assemblies

Relations

• Replaces: ASTM C926-15 - Standard Specification for Application of Portland Cement-Based Plaster
• Effective Date: 01-Jun-2015
• Replaced By: ASTM C926-15b - Standard Specification for Application of Portland Cement-Based Plaster
• Effective Date: 15-Jul-2015
• Referred By: ASTM C1063-23 - Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1764-20 - Standard Test Methods for Non Metallic Plaster Bases (Lath) Used With Portland Cement Based Plaster in Vertical Wall Applications
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1861-23 - Standard Specification for Lathing and Furring Accessories, and Fasteners, for Interior and Exterior Portland Cement-Based Plaster
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1780-23a - Standard Practice for Installation Methods for Cement-based Adhered Masonry Veneer
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1788-20 - Standard Specification for Non Metallic Plaster Bases (Lath) Used With Portland Cement Based Plaster in Vertical Wall Applications
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1328/C1328M-23 - Standard Specification for Plastic (Stucco) Cement
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1324-20a - Standard Test Method for Examination and Analysis of Hardened Masonry Mortar
• Effective Date: 01-Jun-2015
• Referred By: ASTM C1787-23 - Standard Specification for Installation of Non Metallic Plaster Bases (Lath) Used with Portland Cement Based Plaster in Vertical Wall Applications
• Effective Date: 01-Jun-2015
• Referred By: ASTM E2266-22 - Standard Guide for Design and Construction of Low-Rise Frame Building Wall Systems to Resist Water Intrusion
• Effective Date: 01-Jun-2015

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:C926 −15a
StandardSpecification for
1
Application of Portland Cement-Based Plaster
This standard is issued under the fixed designation C926; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* C207Specification for Hydrated Lime for Masonry Pur-
poses
1.1 This specification covers the requirements for the appli-
C219Terminology Relating to Hydraulic Cement
cation of full thickness portland cement-based plaster for
C260Specification for Air-Entraining Admixtures for Con-
exterior (stucco) and interior work.
crete
1.2 This specification sets forth tables for proportioning of
C578Specification for Rigid, Cellular Polystyrene Thermal
various plaster mixes and plaster thickness.
Insulation
C595Specification for Blended Hydraulic Cements
NOTE 1—General information will be found in Annex A1. Design
considerations will be found in Annex A2.
C631Specification for Bonding Compounds for Interior
Gypsum Plastering
1.3 Thevaluesstatedininch-poundunitsaretoberegarded
C897Specification for Aggregate for Job-Mixed Portland
asthestandard.TheSI(metric)valuesgiveninparenthesesare
Cement-Based Plasters
approximate and are provided for information purposes only.
C932 Specification for Surface-Applied Bonding Com-
1.4 The text of this specification references notes and
pounds for Exterior Plastering
footnotes that provide explanatory material. These notes and
C1063Specification for Installation of Lathing and Furring
footnotes (excluding those in tables and figures) shall not be
to Receive Interior and Exterior Portland Cement-Based
considered as requirements of the specification.
Plaster
1.5 Details of construction for a specific assembly to
C1116 Specification for Fiber-Reinforced Concrete and
achieve the required fire resistance shall be obtained from
Shotcrete
reports of fire-resistance tests, engineering evaluations, or
C1328Specification for Plastic (Stucco) Cement
listings from recognized fire testing laboratories.
E90Test Method for Laboratory Measurement of Airborne
Sound Transmission Loss of Building Partitions and
2. Referenced Documents
Elements
2
E119Test Methods for Fire Tests of Building Construction
2.1 ASTM Standards:
and Materials
C11Terminology Relating to Gypsum and Related Building
E492Test Method for Laboratory Measurement of Impact
Materials and Systems
Sound Transmission Through Floor-Ceiling Assemblies
C25Test Methods for Chemical Analysis of Limestone,
Using the Tapping Machine
Quicklime, and Hydrated Lime
2.2 ANSI Standard:
C35Specification for InorganicAggregates for Use in Gyp-
3
A108.1Specification for Installation of Ceramic Tile
sum Plaster
C91Specification for Masonry Cement
3. Terminology
C150Specification for Portland Cement
C206Specification for Finishing Hydrated Lime 3.1 Terms shall be defined as in Terminologies C11 and
C219, except as modified herein.
3.2 Definitions of Terms Specific to This Standard:
1
This specification is under the jurisdiction of ASTM Committee C11 on
3.2.1 accelerator, n—an admixture that will shorten the
GypsumandRelatedBuildingMaterialsandSystemsandisthedirectresponsibility
setting time of plaster.
ofSubcommitteeC11.03onSpecificationsfortheApplicationofGypsumandOther
Products in Assemblies. 3.2.2 admixture, n—a material other than water, aggregate,
CurrenteditionapprovedJune1,2015.PublishedJuly2015.Originallyapproved
or basic cementitious material added to the batch before or
in 1981. Last previous edition approved in 2015 as C926–15. DOI: 10.1520/
during job mixing.
C0926-15A.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036.
*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
1

---------------------- Page: 1 ----------------------
C926−15a
3.2.3 acid etching, n—the cleansing and controlled erosion 3.2.11.9 skim coat, n—a thin finish coat applied to an
of a solid surface, using an acid wash. existing plaster surface or other substrate to improve appear-
ance.
3.2.4 air entrainment, n—the use of an air-entraining ad-
mixtureorair-entrainingcementitiousmaterialinaplastermix
3.2.11.10 three-coat work, n—application of plaster in three
to yield a controlled quantity of minute (typically between 10
successive coats with time between coats for set
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C926 − 15 C926 − 15a
Standard Specification for
1
Application of Portland Cement-Based Plaster
This standard is issued under the fixed designation C926; 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 This specification covers the requirements for the application of full thickness portland cement-based plaster for exterior
(stucco) and interior work.
1.2 This specification sets forth tables for proportioning of various plaster mixes and plaster thickness.
NOTE 1—General information will be found in Annex A1. Design considerations will be found in Annex A2.
1.3 The values stated in inch-pound units are to be regarded as the standard. The SI (metric) values given in parentheses are
approximate and are provided for information purposes only.
1.4 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of the specification.
1.5 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.
2. Referenced Documents
2
2.1 ASTM Standards:
C11 Terminology Relating to Gypsum and Related Building Materials and Systems
C25 Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated Lime
C35 Specification for Inorganic Aggregates for Use in Gypsum Plaster
C91 Specification for Masonry Cement
C150 Specification for Portland Cement
C206 Specification for Finishing Hydrated Lime
C207 Specification for Hydrated Lime for Masonry Purposes
C219 Terminology Relating to Hydraulic Cement
C260 Specification for Air-Entraining Admixtures for Concrete
C578 Specification for Rigid, Cellular Polystyrene Thermal Insulation
C595 Specification for Blended Hydraulic Cements
C631 Specification for Bonding Compounds for Interior Gypsum Plastering
C897 Specification for Aggregate for Job-Mixed Portland Cement-Based Plasters
C932 Specification for Surface-Applied Bonding Compounds for Exterior Plastering
C1063 Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster
C1116 Specification for Fiber-Reinforced Concrete and Shotcrete
C1328 Specification for Plastic (Stucco) Cement
E90 Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements
E119 Test Methods for Fire Tests of Building Construction and Materials
E492 Test Method for Laboratory Measurement of Impact Sound Transmission Through Floor-Ceiling Assemblies Using the
Tapping Machine
1
This specification is under the jurisdiction of ASTM Committee C11 on Gypsum and Related Building Materials and Systems and is the direct responsibility of
Subcommittee C11.03 on Specifications for the Application of Gypsum and Other Products in Assemblies.
Current edition approved Feb. 1, 2015June 1, 2015. Published February 2015July 2015. Originally approved in 1981. Last previous edition approved in 20142015 as
C926 – 14a.C926 – 15. DOI: 10.1520/C0926-15.10.1520/C0926-15A.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
1

---------------------- Page: 1 ----------------------
C926 − 15a
2.2 ANSI Standard:
3
A108.1 Specification for Installation of Ceramic Tile
3. Terminology
3.1 Terms shall be defined as in Terminologies C11 and C219, except as modified herein.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 accelerator, n—an admixture that will shorten the setting time of plaster.
3.2.2 admixture, n—a material other than water, aggregate, or basic cementitious material added to the batch before or during
job mixing.
3.2.3 acid etching, n—the cleansing and controlled erosion of a solid surface, using an acid wash.
3.2.4 air entrainment, n—the use of an air-entraining admixture or air-entraining cementitious material
...