ASTM C474-15(2020)
(Test Method)Standard Test Methods for Joint Treatment Materials for Gypsum Board Construction
Standard Test Methods for Joint Treatment Materials for Gypsum Board Construction
ABSTRACT
These test methods cover the physical testing of joint treatment materials such as joint compound, paper joint tape, glass-mesh joint tape, and an assembly of joint compound and paper joint tape. These materials are used in gypsum board construction. The test methods are detailed for the following: joint compound tests—for viscosity, shrinkage, check cracking, and putrefaction; joint tape tests—for tensile strength, width, and thickness; paper joint tape tests—for dimensional stability; assemblages of paper joint tape and joint compound—for bond of paper joint tape to joint compound and cracking of joint compound at tape edges; and glass-mesh joint tape test—for skewness.
SCOPE
1.1 These test methods cover the physical testing of joint compound, paper joint tape, glass-mesh joint tape, and an assembly of joint compound and paper joint tape.
1.1.1 Joint treatment materials are specified in Specification C475/C475M.
1.1.2 The joint treatment material described in this standard are for use with gypsum board installed in accordance with Specification C840.
1.2 The test methods appear in the following order:
Joint Compound Tests:
Viscosity
5
Shrinkage
6
Check Cracking
7
Putrefaction
8
Joint Tape Tests:
Tensile Strength
9
Width
10
Thickness
11
Paper Joint Tape Tests:
Dimensional Stability
12
Assemblages of Paper Joint Tape and Joint Compound:
Bond of Paper Joint Tape to Joint Compound
15
Cracking of Joint Compound at Tape Edges
14
Glass-Mesh Joint Tape Test:
Skewness
13
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 The text of this standard 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 standard.
1.5 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.
1.6 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.
General Information
Relations
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.
Designation: C474 − 15 (Reapproved 2020)
Standard Test Methods for
Joint Treatment Materials for Gypsum Board Construction
This standard is issued under the fixed designation C474; 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 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 These test methods cover the physical testing of joint
ization established in the Decision on Principles for the
compound, paper joint tape, glass-mesh joint tape, and an
Development of International Standards, Guides and Recom-
assembly of joint compound and paper joint tape.
mendations issued by the World Trade Organization Technical
1.1.1 Joint treatment materials are specified in Specification
Barriers to Trade (TBT) Committee.
C475/C475M.
1.1.2 The joint treatment material described in this standard
2. Referenced Documents
are for use with gypsum board installed in accordance with
Specification C840.
2.1 ASTM Standards:
1.2 The test methods appear in the following order: C11Terminology Relating to Gypsum and Related Building
Materials and Systems
Joint Compound Tests:
Viscosity 5
C472Test Methods for Physical Testing of Gypsum, Gyp-
Shrinkage 6
sum Plasters, and Gypsum Concrete
Check Cracking 7
C475/C475MSpecification for Joint Compound and Joint
Putrefaction 8
Joint Tape Tests:
Tape for Finishing Gypsum Board
Tensile Strength 9
C840SpecificationforApplicationandFinishingofGypsum
Width 10
Board
Thickness 11
Paper Joint Tape Tests:
C1396/C1396MSpecification for Gypsum Board
Dimensional Stability 12
D685Practice for Conditioning Paper and Paper Products
Assemblages of Paper Joint Tape and Joint Compound:
for Testing
Bond of Paper Joint Tape to Joint Compound 15
Cracking of Joint Compound at Tape Edges 14
D828Test Method for Tensile Properties of Paper and
Glass-Mesh Joint Tape Test:
PaperboardUsingConstant-Rate-of-ElongationApparatus
Skewness 13
D1000 Test Methods for Pressure-Sensitive Adhesive-
1.3 The values stated in inch-pound units are to be regarded
Coated Tapes Used for Electrical and ElectronicApplica-
as standard. The values given in brackets are mathematical
tions
conversions to SI units that are provided for information only
D3699Specification for Kerosine
and are not considered standard.
D3882Test Method for Bow and Skew in Woven and
1.4 The text of this standard references notes and footnotes
Knitted Fabrics
that provide explanatory material. These notes and footnotes
E100Specification for ASTM Hydrometers
(excluding those in tables and figures) shall not be considered
E177Practice for Use of the Terms Precision and Bias in
as requirements of the standard.
ASTM Test Methods
E691Practice for Conducting an Interlaboratory Study to
1.5 This standard does not purport to address all of the
Determine the Precision of a Test Method
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
2.2 TAPPI Standard:
priate safety, health, and environmental practices and deter-
T411 Thickness (Caliper) of Paper, Paperboard, and Com-
mine the applicability of regulatory limitations prior to use.
bined Board
These test methods are under the jurisdiction of ASTM Committee C11 on
Gypsum and Related Building Materials and Systems and are the direct responsi- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
bility of Subcommittee C11.02 on Specifications and Test Methods forAccessories contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and Related Products. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2020. Published June 2020. Originally the ASTM website.
approved in 1961. Last previous edition approved in 2015 as C474–15. DOI: Available from TechnicalAssociation of the Pulp and Paper Industry, Technol-
10.1520/C0474-15R20. ogy Park, P.O. Box 105113, Atlanta, GA 30348.
*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
C474 − 15 (2020)
3. Terminology 5.2.1 Sampling shall be in accordance with Specification
C475/C475M.
3.1 Definitions—For definitions of terms relating to
gypsum, see Terminology C11. 5.3 Specimen Preparation:
3.2 Definitions of Terms Specific to This Standard: 5.3.1 Prepare specimens in accordance with Section 4.
3.2.1 bond, n—in joint systems, the quality of adhesion
5.4 Apparatus:
between the paper joint tape and joint compound.
5.4.1 Viscosity Specimen Container,metalorplasticwithan
3.2.1.1 Discussion—A0% bond means that no paper fiber
open top having an inside diameter of 2 ⁄2to 3 in. [65 to
is adhering to the joint compound. 100% bond means that
75mm] and a height of 2 ⁄2to 3 in. [65 to 75 mm].
there is cohesive failure of the paper joint tape. 4
5.4.2 Viscometer , adjusted to operate at 78 6 1 r/min.
3.2.2 check cracking, n—in joint systems, short, narrow
5.4.3 Viscometer Pin (Spindle), having dimensions as fol-
cracks randomly oriented in the surface of the dried joint
lows:
compound.
in. [mm]
Shaft diameter 0.187 ± 0.015 [4.75 ± 0.38]
3.2.3 joint compound, powder, n—a drying-type or setting-
Pin diameter 0.094 ± 0.015 [2.39 ± 0.38]
type cementitious material to be mixed with water.
Immersion depth (from bottom of spindle) 1.625 ± 0.015 [41.3 ± 0.38]
Length of pin projecting from shaft 0.750 ± 0.015 [19.1 ± 0.38]
3.2.4 joint compound, ready-mix, n—a drying-type cemen-
Upper pin from bottom of shaft 0.313 ± 0.015 [7.95 ± 0.38]
titious material that is factory mixed in ready-to-use form.
Lower pin from bottom of shaft 0.125 ± 0.015 [3.28 ± 0.38]
5.5 Procedure:
4. Specimen Preparation
5.5.1 Fill the viscosity container with the mixed specimen
until level with the top of the container.
4.1 Joint Compound, Powder:
5.5.1.1 Remove all air bubbles by puddling the sample
4.1.1 Mix 300 g of joint compound, powder, with approxi-
container with a spatula and sharply rapping the bottom of the
mately 150 to 160 mL of water.
container on a hard flat surface.
4.1.2 Allow the specimen to stand for 30 min (Note 1),
5.5.2 Securethefilledcontainerinthecenteroftheviscom-
remix and adjust the temperature to 77 62°F[25 6 1 °C] by
eter spindle platform. Position the spindle so that the sample
placing the container holding the specimen in warm or cool
comes up to the immersion mark on the pin (spindle).
water.
5.5.3 Start the viscometer and record the viscosity reading
NOTE 1—Allow setting type compounds to stand for one half of their
on the digital display after 30 s. If the viscometer readout goes
setting times, as determined by Test Methods C472 but not more than
to a strip chart recorder, read the viscosity after the pen starts
30min, prior to remixing.
to trace a straight line (usually within 1 min); if the tracing
4.1.3 Measure the viscosity in accordance with Section 5.
remains inconsistent, estimate the average viscosity reading.
4.1.4 If the measured viscosity is not between 480 and
5.6 Report:
520Brabender units, repeat 4.1.1 – 4.1.3 through with an
5.6.1 Report the viscosity of the joint compound specimen
increase or decrease in water as necessary.
in Brabender units.
4.1.5 Record the volume of water used to adjust the viscos-
ity to 500 6 20 Brabender units (see Note 2).
5.7 Precision and Bias:
5.7.1 The precision of this test method is based on an
NOTE 2—Making note of the volumes of water, in millilitres per 100 g
interlaboratory study conducted in 2011. Seven laboratories
of material, used to adjust the viscosity, will facilitate specimen prepara-
tion in other tests.
using Brookfield equipment and eight laboratories using Bra-
bender equipment tested two different materials, by alternative
4.2 Joint Compound, Ready-Mix:
methods. Every test result represents an individual
4.2.1 Remix joint compound, ready-mix, to reincorporate
determination, and each lab was asked to report five replicate
any separated ingredients.Adjust the temperature to 77 62°F
results for each material/instrument combination. Except for
[25 6 1 °C] by placing the container holding the specimen in
the limited amount of data reported for several of the material/
warm or cool water.
instrument combinations, Practice E691 was followed for the
4.2.2 Measure the viscosity in accordance with Section 5.
design and analysis of the data.
4.2.3 If the viscosity is more than 520 Brabender units, add
5.7.1.1 Repeatability Limit (r)—Two test results obtained
water to achieve a viscosity of 500 6 20 Brabender units (see
within one laboratory shall be judged not equivalent if they
Note 2).
differ by more than the “r” value for that material; “r” is the
4.2.3.1 If the original sample viscosity is less than 480Bra-
interval representing the critical difference between two test
bender units, test as received.
results for the same material, obtained by the same operator
JOINT COMPOUND
5. Joint Compound Viscosity The sources of supply of the apparatus known to the committee at this time are
the Brabender “Visco-Corder” Model VC-E, manufactured by C.W. Brabender
5.1 Significance and Use:
Instruments Inc., South Hackensack, NJ. and the Brookfield R/S-SST Rheometer,
5.1.1 This test method provides a procedure for measuring manufactured by Brookfield Engineering Laboraties Inc., Middleboro, MA. If you
are aware of alternative suppliers, please provide this information to ASTM
joint compound viscosity.
International Headquarters. Your comments will receive careful consideration at a
5.2 Sampling: meeting of the responsible technical committee, which you may attend.
C474 − 15 (2020)
TABLE 1 Brookfield R/S SST (Brabender Units) TABLE 2 Brabender VC-E (Brabender Units)
Repeat- Reproduc- Repeat- Reproduc-
Repeat- Reproduc- Repeat- Reproduc-
ability ibility ability ibility
A A
Material Average ability ibility Material Average ability ibility
Standard Standard Standard Standard
x x
ID Limit Limit ID Limit Limit
Deviation Deviation Deviation Deviation
r R r R
S S S S
r R r R
Sample A 660.0 7.6 23.6 21.2 66.0 Sample A 602.7 7.2 28.3 20.1 79.3
Sample B 133.6 1.8 5.7 5.2 15.9 Sample B 123.1 1.9 8.0 5.4 22.4
A A
The average of the laboratories’ calculated averages. The average of the laboratories’ calculated averages.
using the same equipment on the same day in the same
laboratory. Repeatability limits are listed in Tables 1 and 2
6.4.2 Balance,havingasensitivityof10mg(Figs.1and2).
below.
6.4.3 Beaker, Ring Stand, and Wire Cradle (see Fig. 1).
5.7.1.2 Reproducibility Limit (R)—Two test results shall be
6.4.4 ForcedAir Drying Oven, capable of being maintained
judgednotequivalentiftheydifferbymorethanthe“R”value
at 90 to 120 °F [32 to 49 °C].
for that material; “R” is the interval representing the critical
6.4.5 Spatula, having a blade approximately 4 in. by ⁄2in.
difference between two test results for the same material,
[100 by 13 mm].
obtained by different operators using different equipment in
6.4.6 Steel-reinforced Broad Knife, a 5 to 8 in. [130 by
different laboratories. Reproducibility limits are listed in
200mm] drywall broad knife reinforced by a steel bar, 1 in.
Tables 1 and 2 below.
[25mm] wide by ⁄8in. [3 mm] thick, by the knife width,
5.7.1.3 The above terms (repeatability limit and reproduc-
attached to the back of the knife blade ⁄4in. [6 mm] from the
ibility limit) are used as specified in Practice E177.
edge.
5.7.1.4 Any judgment in accordance with statements 9.1.1
6.4.7 Hydrometer, having a range of 0.7 to 0.8 sp gr, in
and 9.2 would have an approximate 95% probability of being
accordance with Specification E100.
correct.
6.4.8 Volumetric Container, a container which has a volume
5.7.2 Bias—At the time of the study, there was no accepted
between 25 and 300 cm .
referencematerialsuitablefordeterminingthebiasforthistest
method, therefore no statement on bias is being made.
6.5 Reagents and Materials:
5.7.3 The precision statement was determined through sta-
6.5.1 Displacement Fluids.
tistical examination of 296 results, by alternative methods, on
6.5.1.1 Mineral Spirits, odorless.
two materials (described below).
6.5.1.2 Kerosine (see Specification D3699).
5.7.3.1 Sample A—A representative conventional weight
6.6 Preparation of Apparatus:
ready-mixed all-purpose joint compound prepared specifically
6.6.1 Support Plates—Cover three plastic or glass plates
for the round-robin test and distributed to all testing laborato-
with plastic or rubber film.
ries.
6.6.2 Obtain and record the tare weight of each assembly.
5.7.3.2 Sample B—A representative low-viscosity wall tex-
6.7 Calibration:
ture compound prepared specifically for the round-robin test
6.7.1 Volumetric Container—Determine the container vol-
and distributed to all testing laboratories.
ume in cubic centimetres and its tare weight in grams.
6. Shrinkage
6.7.2 Mineral Spirits, Kerosine—Using the hydrometer, de-
termine the specific gravity and record the result as density M,
6.1 Significance and Use:
g/mL.
6.1.1 Thistestisusedtomeasuretheamountofshrinkagein
joint compound. The degree of correlation between this test
6.8 Determination of Density of Wet Compound:
and service performance has not been determined.
6.8.1 Prepare a specimen to determine the density of wet
compound by weighing the specimen in the volumetric con-
6.2 Sampling:
tainer.
6.2.1 Sampling shall be in accordance with Specification
6.8.1.1 Adjust the temperature to 70 62°F[21 6 1 °C] by
C475/C475M.
placing the container holding the specimen in warm or cool
6.3 Specimen Preparation:
water.
6.3.1 Specimen preparation shall be in accordance with
6.8.1.2 Puddle the specimen within the container with the
Section 4.
spatula to remove entrapped air bubbles.
6.4 Apparatus:
6.8.1.3 Finish filling the container and strike off the surface
6.4.1 Plastic or Rubber Film, approximately 5 by 5 in. [130
flush with the top using the steel-reinforced broad knife.
by 130 mm]. Any thin, flexible film that peels clean from a
6.8.1.4 Weigh the filled container to the nearest 0.01 g.
partially dried patty may be used.
Record the weight of the filled container.
6.8.1.5 Determine the net weight of the compound in the
5 volumetric container by subtracting the weight obtained in
Rubber dental dam dusted with talc, polyethylene, or PTF
...
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