ASTM C1860-23ce1

Standard Test Methods for Measurement of Tensile Strength or Bond Strength of Portland Cement-Based Plaster by Direct Tension

SIGNIFICANCE AND USE
4.1 The purpose of the test methods in this standard is to measure the tensile strength or bond strength of portland cement-based plaster to its substrate. The values obtained using the test methods are not purported to be representative of the actual wind load capacity or other structural properties of a specific portland cement-based plaster installation but may be helpful in assessing such load capacities.  
4.2 Because the test methods described in this standard are used for evaluation of portland cement-based plaster cured at least 28 days, load results obtained by either test method must be interpreted based on sound engineering practice, applicable building regulations, and codes having jurisdiction. The decision of whether to use the load results directly or to use the load results as modified by an appropriate safety factor to obtain acceptable working loads is left to the discretion of the test specifier. Determination of an appropriate safety factor shall be left to the discretion of the test specifier. Methods to calculate a safety factor and a maximum permitted working load are provided in the appendixes.  
4.3 When the test methods contained in this standard are used on test specimens installed on existing structures, the test results shall not be generalized to a larger wall area without sufficient test sampling. Such efforts should be based on engineering experience and judgment of the test specifier.
SCOPE
1.1 These test methods cover procedures for determining the tensile strength of a section of portland cement-based plaster, the bond strength between portland cement-based plaster and a solid plaster base, or the fastener pull-out or lath pull-over strength for portland cement-based plaster bases over framing in either an exterior (stucco) or interior application. The test procedures are destructive in nature within the localized test areas and, after testing is concluded, require appropriate repair of the finish system as well as any underlying materials damaged during testing.  
1.2 These test methods are suitable for use on portland cement-based plaster finish systems on both new and existing construction. Test methods shall be conducted a minimum of 28 days after application of the portland cement-based plaster. Mechanical Load Test Method A and Vacuum Chamber Testing shall be used to determine the tensile strength or bond strength of direct-applied portland cement-based plaster and may be useful in evaluating the efficacy of different surface preparation characteristics, bonding agents, or both. Mechanical Load Test Method B and Vacuum Chamber Testing shall be used to determine the tensile strength of portland cement-based plaster installed over mechanically attached lath.  
1.3 These test methods are suitable for use in both laboratory and field samples. No correlation shall be made between laboratory and field testing.  
1.4 These test methods are not intended to evaluate the performance of the underlying construction or framing members. Test results on a particular building may be variable depending on the specimen location, condition, and installation, and are subject to interpretation by the test specifier.  
1.5 These test methods are not intended to evaluate the performance of coatings applied to the surface of the portland cement-based plaster.  
1.6 These test methods are not intended to be a pre-construction qualifier to determine if the surfaces are appropriate for application of portland cement plaster. The test methods are intended to be used as a tool to quantitatively evaluate existing portland cement plaster cladding that is suspected of questionable bond or uncertain fastening to the substrate.  
1.7 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.  
1.8 This standard may involve...

General Information

• Status: Published
• Publication Date: 31-May-2023
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.02 - Specifications and Test Methods for Accessories and Related Products

Relations

• Refers: ASTM C219-24 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2024
• Refers: ASTM E2359/E2359M-13(2023) - Standard Test Method for Field Pull Testing of an In-Place Exterior Insulation and Finish System Clad Wall Assembly
• Effective Date: 01-Oct-2023
• Refers: ASTM C219-20a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Aug-2020
• Refers: ASTM C219-20 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2020
• Refers: ASTM C219-19a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 15-Nov-2019
• Refers: ASTM C219-19 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jun-2019
• Refers: ASTM C11-18a - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Oct-2018
• Refers: ASTM E2359/E2359M-13(2018) - Standard Test Method for Field Pull Testing of an In-Place Exterior Insulation and Finish System Clad Wall Assembly
• Effective Date: 01-Sep-2018
• Refers: ASTM C11-18 - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Jun-2018
• Refers: ASTM C11-17a - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Oct-2017
• Refers: ASTM C11-17 - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 15-May-2017
• Refers: ASTM C11-16 - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 15-May-2016
• Refers: ASTM C11-15a - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Oct-2015
• Refers: ASTM C11-15 - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Apr-2015
• Refers: ASTM C219-14 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jul-2014

Overview

ASTM C1860-23ce1 is the Standard Test Methods for Measurement of Tensile Strength or Bond Strength of Portland Cement-Based Plaster by Direct Tension. Developed by ASTM International, this standard outlines procedures for evaluating the tensile and bond strength of Portland cement-based plaster, commonly known as stucco, to its substrate. The methods detailed in ASTM C1860 are crucial for assessing the integrity of plaster systems in both new and existing buildings, ensuring durability and safety under various design loads.

These test methods apply to both interior and exterior applications, utilizing direct tension and vacuum chamber approaches. Results are intended for use as part of engineering evaluations and are not a direct representation of actual wind load resistance or other structural properties.

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Key Topics

• Tensile Strength and Bond Strength Testing
  The standard details methods for determining:

  • Tensile strength of a plaster section
  • Bond strength between plaster and substrate
  • Fastener pull-out or lath pull-over strength (when installed over framing)

• Test Scope and Limitations

  • Suitable for Portland cement-based plaster on both new construction and retrofit or existing structures
  • Minimum curing of 28 days required before testing
  • Test results are not intended to represent entire wall areas without sufficient sampling and engineering interpretation

• Sampling and Testing Procedures

  • Describes both laboratory and field procedures
  • Specifies destructive testing methods-localized repair is required afterward
  • Explains targeted, blind, and proof sampling strategies
  • Details apparatus requirements, specimen preparation, and failure mode documentation

• Data Interpretation and Reporting

  • Emphasizes the need for interpretation in the context of building codes and engineering judgment
  • Offers guidance on test report content, including specimen location, test conditions, failure descriptions, and specimen dimensions
  • Safety factor determination and calculation methods provided in appendices

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Applications

ASTM C1860-23ce1 serves several practical applications for construction professionals, engineers, and building inspectors:

• Quality Assessment
  Verify bond and tensile strength of Portland cement plaster applied to both new buildings and repairs, helping ensure the cladding meets safety standards and performs as intended.

• Failure Investigation
  Diagnose issues in building envelopes where debonding, delamination, or suspected weakness in plaster systems is present. Targeted or blind sampling helps identify problematic areas.

• Compliance and Engineering Decisions
  Use test data to inform compliance with applicable building regulations or to assist in determining appropriate safety factors for specific installations.

• Performance Evaluation
  Evaluate the efficacy of various surface preparation methods and bonding agents by comparing the measured bond strengths under controlled, repeatable conditions.

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Related Standards

For comprehensive project evaluations or when specifying plaster systems, the following standards may also be relevant:

• ASTM C11 - Terminology Relating to Gypsum and Related Building Materials and Systems
• ASTM C219 - Terminology Relating to Hydraulic and Other Inorganic Cements
• ASTM E2359/E2359M - Test Method for Field Pull Testing of In-Place Exterior Insulation and Finish System Clad Wall Assemblies
• ASCE/SEI 7 - Minimum Design Loads for Buildings and Other Structures
• U.S. DOC Voluntary Product Standard PS 1 - Structural Plywood

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By following ASTM C1860-23ce1, stakeholders can obtain standardized, reliable data for assessing the adhesive and tensile integrity of Portland cement-based plaster systems. This process is essential for maintaining building safety, validating repair work, and ensuring long-term performance in both residential and commercial applications.

Keywords: ASTM C1860, Portland cement-based plaster, stucco, tensile strength, bond strength, direct tension test, vacuum chamber testing, construction standards, plaster evaluation, building code compliance.

Standards Content (Sample)

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.
´1
Designation: C1860 − 23c
Standard Test Methods for
Measurement of Tensile Strength or Bond Strength of
Portland Cement-Based Plaster by Direct Tension
This standard is issued under the fixed designation C1860; 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.
ε NOTE—Editorially corrected Appendix X4 in September 2023.
1. Scope 1.5 These test methods are not intended to evaluate the
performance of coatings applied to the surface of the portland
1.1 These test methods cover procedures for determining
cement-based plaster.
the tensile strength of a section of portland cement-based
plaster, the bond strength between portland cement-based 1.6 These test methods are not intended to be a pre-
plaster and a solid plaster base, or the fastener pull-out or lath construction qualifier to determine if the surfaces are appro-
pull-over strength for portland cement-based plaster bases over priate for application of portland cement plaster. The test
framing in either an exterior (stucco) or interior application. methods are intended to be used as a tool to quantitatively
The test procedures are destructive in nature within the evaluate existing portland cement plaster cladding that is
localized test areas and, after testing is concluded, require suspected of questionable bond or uncertain fastening to the
appropriate repair of the finish system as well as any underly- substrate.
ing materials damaged during testing.
1.7 The values stated in inch-pound units are to be regarded
1.2 These test methods are suitable for use on portland as standard. The values given in parentheses are mathematical
cement-based plaster finish systems on both new and existing conversions to SI units that are provided for information only
construction. Test methods shall be conducted a minimum of and are not considered standard.
28 days after application of the portland cement-based plaster.
1.8 This standard may involve hazardous materials,
Mechanical Load Test Method A and Vacuum Chamber Testing
operations, or equipment. This standard does not purport to
shall be used to determine the tensile strength or bond strength
address all of the safety concerns, if any, associated with its
of direct-applied portland cement-based plaster and may be
use. It is the responsibility of the user of this standard to
useful in evaluating the efficacy of different surface preparation
establish appropriate safety, health, and environmental prac-
characteristics, bonding agents, or both. Mechanical Load Test
tices and determine the applicability of regulatory limitations
Method B and Vacuum Chamber Testing shall be used to
prior to use.
determine the tensile strength of portland cement-based plaster
1.9 This international standard was developed in accor-
installed over mechanically attached lath.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
1.3 These test methods are suitable for use in both labora-
Development of International Standards, Guides and Recom-
tory and field samples. No correlation shall be made between
mendations issued by the World Trade Organization Technical
laboratory and field testing.
Barriers to Trade (TBT) Committee.
1.4 These test methods are not intended to evaluate the
performance of the underlying construction or framing mem-
2. Referenced Documents
bers. Test results on a particular building may be variable
2.1 ASTM Standards:
depending on the specimen location, condition, and
C11 Terminology Relating to Gypsum and Related Building
installation, and are subject to interpretation by the test
Materials and Systems
specifier.
C219 Terminology Relating to Hydraulic and Other Inor-
ganic Cements
E2359/E2359M Test Method for Field Pull Testing of an
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. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 1, 2023. Published June 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2018. Last previous edition approved in 2023 as C1860 – 23b. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1860-23CE01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C1860 − 23c
In-Place Exterior Insulation and Finish System Clad Wall sion of whether to use the load results directly or to use the load
Assembly results as modified by an appropriate safety factor to obtain
acceptable working loads is left to the discretion of the test
2.2 American Society of Civil Engineers Standard:
SEI/ASC 7 Minimum Design Loads for Buildings and Other specifier. Determination of an appropriate safety factor shall be
left to the discretion of the test specifier. Methods to calculate
Structures
a safety factor and a maximum permitted working load are
2.3 U.S. Department of Commerce Standard:
provided in the appendixes.
Voluntary Product Standard PS 1 Structural Plywood
4.3 When the test methods contained in this standard are
3. Terminology
used on test specimens installed on existing structures, the test
3.1 Terms shall be as defined in Terminology C11 and
results shall not be generalized to a larger wall area without
Terminology C219, except as modified herein.
sufficient test sampling. Such efforts should be based on
engineering experience and judgment of the test specifier.
3.2 Definitions:
3.2.1 adhesive, n—high strength adhesive of appropriate
5. Apparatus
type to adhere test module to plaster; expanding foam adhe-
sives shall be prohibited.
5.1 Mechanical Testing Apparatus:
3.2.2 bond strength, n—the maximum stress as measured in 5.1.1 Pull test frame fabricated from metal or wood, as
force per unit area that a plaster specimen can withstand in required, with capability of applying a concentric pull force to
direct tension before failure either (a) between any two stucco the test module and distributing reaction forces on adjacent
coats, or (b) between the base coat(s) and the substrate. wall components. It is intended that the pull test frame be
easily transportable and relocated so that it can readily be used
3.2.3 fastener pull-out, n—failure mode by which the fas-
on saw-horses, scaffolding, lifts, and swing-stages. The pull
tener released from the substrate in withdrawal.
test frame as specified in Test Method E2359/E2359M shall be
3.2.4 lath, n—a mechanically attached base material used to
permitted in this test method.
support plaster including metal plaster bases (expanded metal
5.1.2 A coupling device to connect the pull test module to
lath, woven wire plaster base, and welded wire lath) and
the load cell and test frame. The coupling device shall be
non-metallic plaster bases.
designed to withstand the tensile capacity of the device without
3.2.5 lath pull-over, n—failure mode by which the lath
yielding, and to transmit the tensile force parallel to and in line
(metal or non-metallic) pulls over the head of the fastener,
with centerline of the test specimen without imparting torsion
leaving the fastener intact.
or bending stress to the specimen. The coupling device shall be
3.2.6 proof, n—the maximum safe test load as set in this fitted with a metal rod fixed at the load cell and threaded at the
opposite end to permit the application of tensile loads to the
standard.
test module in a controlled manner with incrementally increas-
3.2.7 substrate, n—the surface to which the plaster is
ing load intensities.
attached, either directly or with lath (metal or non-metallic).
5.1.3 A load cell with force gauge having a capacity of at
3.2.8 tensile load, n—the load as measured in force that a
least the proof values specified in 7.1.3, and an accuracy of
plaster specimen can withstand in direct tension at failure.
62 %. Load cells shall be calibrated annually.
3.2.9 tensile strength, n—the stress as measured in force per
5.1.4 Electric angle grinder with masonry cutting blade of
unit area that a plaster specimen can withstand in direct tension
sufficient type and diameter to fully penetrate plaster thickness
before failure within any individual stucco coat.
and lath and grinding blade to level surface of plaster.
5.1.5 Miscellaneous hand tools, bolts, and connection hard-
4. Significance and Use
ware.
4.1 The purpose of the test methods in this standard is to
5.1.6 Test Method A (Direct-applied Stucco Testing):
measure the tensile strength or bond strength of portland
5.1.6.1 Pull test module consisting of a minimum 6 by 6 in.
cement-based plaster to its substrate. The values obtained using
(150 by 150 mm) and maximum 24 by 24 in. (610 by 610 mm)
the test methods are not purported to be representative of the
U.S. DOC Voluntary Product Standard PS 1 rated plywood
actual wind load capacity or other structural properties of a 3
minimum of ⁄4 in. (19 mm) nominal thickness bonding panel
specific portland cement-based plaster installation but may be
(one for each specimen intended for testing) and one minimum
helpful in assessing such load capacities. 1
⁄4 in. (6 mm) thick steel plate transfer panel sized to match
length and width of the wooden bonding panel which is moved
4.2 Because the test methods described in this standard are
from specimen to specimen (see Note 1). The steel transfer
used for evaluation of portland cement-based plaster cured at
panel shall include an integral steel nut located at the plan
least 28 days, load results obtained by either test method must
center of the plate of size to receive the threaded rod that
be interpreted based on sound engineering practice, applicable
connects the load cell to the transfer panel and provisions for
building regulations, and codes having jurisdiction. The deci-
⁄8 in. (22 mm) length, No. 14 wood screws to fasten the steel
transfer panel to the plywood bonding panel. Adhere one
Available from American Society of Civil Engineers (ASCE), 1801 Alexander
nominal ⁄4 in. (19 mm) thick wooden bonding panel to the
Bell Dr., Reston, VA 20191, http://www.asce.org.
surface of the stucco at each specimen location. For testing
Available from National Institute of Standards and Technology (NIST), 100
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. purposes, temporarily fasten the steel transfer panel at each
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C1860 − 23c
adhered plywood bonding panel in succession. Fasteners be- 5.2.3 An additional pressure tap and pressure sending de-
tween the steel transfer panel and plywood bonding panel shall vice (for example, a manometer) shall be installed to measure
be spaced at a minimum 2 in. (50 mm) on center and maximum the pressure at the interface of the stucco and the solid substrate
2 in. (50 mm) edge distance. (See Figs. 1 and 2 for an example (in other words, the back side of the stucco) to ensure a
of a 12 by 12 in. (300 by 300 mm) test module.) differential pressure during testing and measure interior pres-
surization values, if any. Apply sealant around the exterior
NOTE 1—Pull test module shall be sized as large as possible to capture
circumference of the pressure tap and tubing to prevent
as large of a stucco area as possible. In consideration of geometrical
incorrect readings. This pressure tap shall be permitted to be
constraints and safety hazards associated with the weight and size of the
steel transfer panels sized to match the plywood bonding panels, a installed outside of the chamber to prevent damage during
minimum pull test module size of 6 by 6 in. (150 by 150 mm) shall be
testing. Location of the pressure tap outside of the confines of
permitted.
the vacuum chamber shall be limited to within 3 in. (75 mm)
5.1.7 Test Method B (For Testing Stucco over Mechanically
of the chamber. The devices shall be calibrated to indicate
Attached Lath): negative pressures in increments of no greater than 3 6 0.5 psf
5.1.7.1 Pull test module consisting of a 26 by 26 in. (660 by (145 6 20 Pa).
660 mm) U.S. DOC Voluntary Product Standard PS 1 rated
5.2.4 Vacuum generating equipment shall have sufficient
plywood minimum of ⁄4 in. (19 mm) nominal thickness bond-
capacity to create the negative pressures required for the test.
ing panel (one for each specimen intended for testing) and one
The chamber vacuum equipment shall be equipped with
26 by 26 by ⁄4 in. (660 by 660 by 6 mm) thick steel plate
controls to maintain the constant negative pressure at each test
transfer panel which is moved from specimen to specimen. The pressure increment.
steel transfer panel shall include an integral steel nut located at
5.2.5 Measurement of stucco surface deflections within the
the plan center of the plate of size to receive the threaded rod
test area shall be permitted. A deflection measurement device
that connects the load cell to the transfer panel and provisions
(such as a dial indicator), with graduations of at least 0.002 in.
for ⁄8 in. (22 mm) length, No. 14 wood screws to fasten the
(0.05 mm) units and having at least a 2 in. (50 mm) range,
steel transfer panel to the plywood bonding panel. Adhere one
mounted at the center of a 2 by 2 in. (50 by 50 mm) aluminum
⁄4 in. (19 mm) thick wooden bonding panel to the surface of
bar or member of equivalent stiffness with a length equivalent
the stucco at each specimen location. For testing purposes,
to the long dimension of the test chamber shall be provided for
temporarily fasten the steel transfer panel at each adhered
such measurement. The deflection measurement device shall
plywood bonding panel in succession. Fasteners between the
be installed with a clear distance of at least 2 in. (50 mm) from
steel transfer panel and plywood bonding panel shall be spaced
the stucco surface to allow for measurement.
at a minimum 2 in. (50 mm) on center and maximum 2 in.
5.2.6 A cutting device (for example, an electric angle
(50 mm) edge distance. (See Figs. 3 and 4 for an example of a
grinder) with a masonry cutting blade of sufficient type and
26 by 26 in. (660 by 660 mm) test module.)
diameter to fully penetrate plaster thickness and lath (where
5.1.8 As an alternate to the ⁄4 in. (6 mm) steel transfer panel
applicable).
specified in 5.1.6.1 and 5.1.7.1, the test specifier shall be
5.2.7 Miscellaneous hand tools, bolts, and connection hard-
permitted to substitute a minimum ⁄4 in. (19 mm) U.S. DOC
ware.
Voluntary Product Standard PS 1 rated plywood transfer panel
of equivalent dimensions.
6. Test Specimen
5.1.9 An exploded view of the test assembly components
6.1 Sampling:
(pull test frame, coupling device, load cell, and pull test
module as described in 5.1.1, 5.1.2, 5.1.3, 5.1.6, and 5.1.7, 6.1.1 Sampling locations and number of specimens shall be
respectively) is shown in Fig. 5. The feet of the pull test frame determined by test specifier.
shall be of size and thickness to adequately distribute the loads
6.1.2 Test Method A (direct-applied stucco testing) sam-
to the wall without interfering with the performance of the test.
pling shall fall within three categories as specified in this
section.
5.2 Vacuum Chamber Apparatus:
6.1.2.1 Blind Sampling—Sampling specified without any
5.2.1 Chamber test frame shall be constructed of acrylic,
knowledge, perception, or expectation of the results shall be
polycarbonate, metal, or wood with a clear plastic window to
referred to as blind sampling. Locations and number of blind
permit viewing of the test specimen. The test frame shall be
sampling specimens shall be determined by the test specifier.
sufficiently strong to withstand the necessary anticipated nega-
6.1.2.2 Targeted Sampling—Where sampling is targeted in
tive pressure.
areas with suspect deficiencies, such sampling shall be identi-
5.2.2 A pressure sensing device (for example, a manometer)
fied and the means by which the targeted areas were identified
for measuring the negative pressure shall be located inside the
(for example, acoustical sounding) shall be described in the
chamber or located outside the chamber such that a pressure
report.
tap is located within the chamber to measure internal negative
pressure. The device shall be calibrated to indicate negative 6.1.2.3 Proof Sampling—Where sampling is targeted in
pressures in increments of no greater than 3 6 0.5 psf (145 6 areas to validate or verify that the stucco is properly bonded
20 Pa). The design or safety features of the device shall not be (proof sampling), such sampling shall be identified and the
changed to increase negative pressures above the design or means by which the targeted areas were identified (for
allowable values of the chamber. example, acoustical sounding) shall be described in the report.
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C1860 − 23c
FIG. 1 Example of 12 by 12 in. (300 by 300 mm) Bonding Panel
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C1860 − 23c
FIG. 2 Sample Layout of 12 in. (300 mm) Square Steel Bolting Template
6.1.3 Test Method B (stucco over mechanically attached specified vacuum cannot be obtained. Where the specified
lath testing) sampling shall be blind or targeted as defined in vacuum cannot be obtained because of the surface texture in
6.1.2.1 and 6.1.2.2, respectively. the surface of the stucco, preparation of the surface via hand
grinding shall be permitted.
6.2 Surface Preparation:
6.2.1 Mechanical Tensile Load Apparatus (Methods A and 6.3 Mechanical Tensile Load Testing—Test Method A:
B). 6.3.1 Where testing is to be performed at a targeted area of
6.2.1.1 Remove all surface contaminants, loose debris, and suspected unbonded or debonded stucco (determined through
dust that may interfere with bond. sounding or another applicable method), the area to be tested
6.2.1.2 If surface texture profile of plaster is such that good shall be a square equal to the suspected area of unbonded or
bond cannot be achieved, grind the surface texture to a level debonded stucco multiplied by a factor of two, up to a
surface that permits good bond. maximum area of 24 by 24 in. (610 by 610 mm). Where testing
6.2.2 Vacuum Test Method—Surface preparation of surfaces is randomized, the area to be tested shall be sized to match the
is generally not required for the vacuum test method unless the wood bonding panel as described in 5.1.6.1.
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C1860 − 23c
FIG. 3 Example of 26 in. (660 mm) Square Plywood Bonding Panel for Framing Members Spaced at 24 in. (610 mm) or Less
6.3.2 Where test samples are located adjacent to utility is complete, apply air impermeable tape over the scored joint to
penetrations, geometric conditions (for example, changes in prevent air leakage during testing.
planarity, corners, edges, etc.), or other features that will not 6.3.4 Attach the plywood bonding panel to the surface of the
allow for safe mounting or operation of the testing apparatus, test specimen using the adhesive. Apply sufficient amount(s) of
the test specifier shall be permitted to modify the size and adhesive to allow for development of proof loading. Ensure
location of the test. These modifications shall be reported, that the plywood is centered on the test specimen and the edges
described, and justified in the report in accordance with Section of the plywood align with the edges of the score cut. Apply and
9 of this test method. cure the adhesive in accordance with the manufacturer’s
6.3.3 Mark an outline over the area to be tested as described instructions. Prevent adhesive that drips down the side of the
in 6.3.1. Cut along the outline through the full depth of the specimen and into the annular cut from setting by wiping clean;
stucco and lath, taking care to avoid damaging the substrate. if setting occurs, cutting along the outline of the specimen shall
Ensure that the cut depth and width is adequate to isolate the be repeated. Temporarily brace the panel to the specimen as
test area and prevent influence of the test results. After cutting necessary to prevent slippage while adhesive cures. Provide
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C1860 − 23c
FIG. 4 Sample Layout of 26 in. (660 mm) Square Steel Bolting Template for Framing Members Spaced at 24 in. (610 mm) or Less
temporary protection as required by the adhesive manufactur- centered on the test specimen and the edges of the plywood
er’s installation instructions. align with the edges of the cut. Apply and cure the adhesive in
accordance with the manufacturer’s instructions. Prevent ad-
6.4 Mechanical Tensile Load Testing—Test Method B:
hesive that drips down the side of the specimen and into the
6.4.1 Determine the location of framing members within the
annular cut from setting by wiping clean; if setting occurs,
sampling location via non-destructive testing methods, such as
cutting along the outline of the specimen shall be repeated.
infrared thermography.
Temporarily brace the panel to the specimen as necessary to
6.4.2 Mark a 26 by 26 in. (660 by 660 mm) outline centered
prevent slippage while adhesive cures.
over the framing members. Cut along the outline through the
full depth of the stucco and plaster base, only scoring the 6
...