ASTM C687-18

Standard Practice for Determination of Thermal Resistance of Loose-Fill Building Insulation

SIGNIFICANCE AND USE
4.1 The thermal resistance, R, of an insulation is used to describe its thermal performance.  
4.2 The thermal resistance of an insulation is related to the density and thickness of the insulation. It is desirable to obtain test data on thermal resistances at thicknesses and densities related to the end uses of the product.  
4.3 In normal use, the thickness of these products range from less than 100 mm (4 in.) to greater than 500 mm (20 in.). Installed densities depend upon the product type, the installed thickness, the installation equipment used, the installation techniques, and the geometry of the insulated space.  
4.4 Loose-fill insulations provide coverage information using densities selected by manufacturers to represent the product settled densities. Generally, it is necessary to know the product thermal performance at a representative density. Some coverage charts utilize multiple densities to show that greater thickness installations usually result in higher installed densities. The use of multiple densities can be detected from the coverage chart by calculating the density for several different thermal resistance levels. (The density for a given thermal resistance can be calculated from the coverage chart by dividing the minimum mass per unit area by the minimum thickness.) If the calculated densities are significantly different at different thermal resistances, the multiple density strategy has been used.  
4.5 When applicable specifications or codes do not specify the nominal thermal resistance level to be used for comparison purposes, a recommended practice is to use the Rsi (metric) = 3.3 m2K/W (RIP = 19 [h ft2F/Btu]) label density and thickness for that measurement.  
4.6 If the density for test purposes is not available from the coverage chart, a test density shall be established by use of applicable specifications and codes or, if none apply, agreement between the requesting body and the testing organization.  
4.7 Generally, thin sections o...
SCOPE
1.1 This practice presents a laboratory guide to determine the thermal resistance of loose-fill building insulations at mean temperatures between −20 and 55°C (−4 to 131°F).  
1.2 This practice applies to a wide variety of loose-fill thermal insulation products including but not limited to fibrous glass, rock/slag wool, or cellulosic fiber materials; granular types including vermiculite and perlite; pelletized products; and any other insulation material installed pneumatically or poured in place. It does not apply to products that change their character after installation either by chemical reaction or the application of binders or adhesives, nor does it consider the effects of structures, containments, facings, or air films.  
1.3 Since this practice is designed for reproducible product comparison, it measures the thermal resistance of an insulation material which has been preconditioned to a relatively dry state. Consideration of changes of thermal performance of a hygroscopic insulation by sorption of water is beyond the scope of this practice.  
1.4 The sample preparation techniques outlined in this practice do not cover the characterization of loose-fill materials intended for enclosed applications. For those applications, a separate sample preparation technique that simulates the installed condition will be required. However, even for those applications, some other aspects of this practice are applicable.  
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.6 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.  
1.7 This international standard was developed in accordance with internationa...

General Information

• Status: Published
• Publication Date: 31-Aug-2018
• ICS: 91.120.10 - Thermal insulation of buildings
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.30 - Thermal Measurement

Relations

• Replaces: ASTM C687-17 - Standard Practice for Determination of Thermal Resistance of Loose-Fill Building Insulation
• Effective Date: 01-Sep-2018
• Refers: ASTM C168-24 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2024
• Refers: ASTM C739-24 - Standard Specification for Cellulosic Fiber Loose-Fill Thermal Insulation
• Effective Date: 01-Mar-2024
• Refers: ASTM C1363-24 - Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
• Effective Date: 01-Mar-2024
• Refers: ASTM C1363-19 - Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
• Effective Date: 01-Sep-2019
• Refers: ASTM C1045-19 - Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
• Effective Date: 01-Apr-2019
• Refers: ASTM C168-18 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2018
• Refers: ASTM C168-17 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jun-2017
• Refers: ASTM C653-17 - Standard Guide for Determination of the Thermal Resistance of Low-Density Blanket-Type Mineral Fiber Insulation
• Effective Date: 01-Mar-2017
• Refers: ASTM C168-15a - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Oct-2015
• Refers: ASTM C167-15 - Standard Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations
• Effective Date: 01-Sep-2015
• Refers: ASTM C518-15 - Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
• Effective Date: 01-Sep-2015
• Refers: ASTM C168-15 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jun-2015
• Refers: ASTM C1114-06(2013) - Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus
• Effective Date: 01-Sep-2013
• Refers: ASTM C1045-07(2013) - Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
• Effective Date: 01-Sep-2013

Overview

ASTM C687-18 is the internationally recognized standard practice for the determination of thermal resistance (R-value) of loose-fill building insulation. Published by ASTM International, this standard provides a comprehensive laboratory guide for evaluating the thermal performance of various loose-fill insulation materials used in building envelopes. The standard is applicable to a wide range of products, including fibrous glass, rock wool, slag wool, cellulosic fiber, vermiculite, perlite, and other granular or pelletized materials that are pneumatically installed or poured in place. ASTM C687-18 is a valuable reference for professionals involved in energy efficiency, building material testing, and compliance with insulation codes and regulations.

Key Topics

• Thermal Resistance (R-Value): Focuses on measuring the thermal resistance of insulation materials, a key indicator of their performance in reducing heat flow.
• Material Applicability: Covers a variety of loose-fill products, excluding those that chemically change after installation or require binders/adhesives.
• Testing Conditions: Specifies a mean temperature range of -20°C to 55°C (-4°F to 131°F) to reflect real-use conditions in diverse climates.
• Density and Thickness: Highlights the importance of testing thermal resistance at relevant installed densities and thicknesses, acknowledging their influence on R-value.
• Sample Preparation: Offers guidance for consistent specimen preparation, including pneumatic (blown-in) or poured-in-place methods, to replicate field installation.
• Test Methods: Recommends established ASTM test methods such as the Heat Flow Meter (C518), Guarded-Hot-Plate (C177), and Thin-Heater Apparatus (C1114).
• Result Comparisons: Ensures reproducibility and comparability of R-value data across manufacturers and product types.
• Safety and Compliance: Notes the responsibility of users to observe safety, health, and environmental practices during laboratory testing.

Applications

ASTM C687-18 is widely used in the building construction and insulation industry for:

• Product Certification: Providing manufacturers, laboratories, and certification bodies with a standardized procedure for verifying the R-value of loose-fill insulation products.
• Building Code Compliance: Supporting compliance with energy codes that require specific insulation performance in attics, walls, and floors.
• Quality Assurance: Allowing architects, specifiers, and quality control professionals to make informed decisions on insulation selection for thermal efficiency.
• Research and Product Development: Aiding researchers and product developers in comparing new materials or improving existing insulation products for better thermal performance.
• Consumer Information: Delivering accurate R-value information for comparison shopping and regulatory labeling.

Related Standards

Professionals referencing ASTM C687-18 should also consider the following related ASTM standards for a comprehensive approach to insulation testing and terminology:

• ASTM C167 - Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations
• ASTM C168 - Terminology Relating to Thermal Insulation
• ASTM C177 - Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
• ASTM C518 - Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
• ASTM C739 - Specification for Cellulosic Fiber Loose-Fill Thermal Insulation
• ASTM C1045 - Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
• ASTM C1114 - Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus
• ASTM C1363 - Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
• ASTM C1373 - Practice for Determination of Thermal Resistance of Attic Insulation Systems Under Simulated Winter Conditions

ASTM C687-18 plays a critical role in ensuring reliable and comparable thermal resistance data for loose-fill insulations, supporting energy efficiency and quality standards in the construction industry.

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: C687 − 18
Standard Practice for
Determination of Thermal Resistance of Loose-Fill Building
Insulation
This standard is issued under the fixed designation C687; 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 ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This practice presents a laboratory guide to determine
mendations issued by the World Trade Organization Technical
thethermalresistanceofloose-fillbuildinginsulationsatmean
Barriers to Trade (TBT) Committee.
temperatures between−20 and 55°C (−4 to 131°F).
1.2 This practice applies to a wide variety of loose-fill
2. Referenced Documents
thermalinsulationproductsincludingbutnotlimitedtofibrous
2.1 ASTM Standards:
glass, rock/slag wool, or cellulosic fiber materials; granular
C167Test Methods forThickness and Density of Blanket or
types including vermiculite and perlite; pelletized products;
Batt Thermal Insulations
and any other insulation material installed pneumatically or
C168Terminology Relating to Thermal Insulation
poured in place. It does not apply to products that change their
C177Test Method for Steady-State Heat Flux Measure-
character after installation either by chemical reaction or the
ments and Thermal Transmission Properties by Means of
application of binders or adhesives, nor does it consider the
the Guarded-Hot-Plate Apparatus
effects of structures, containments, facings, or air films.
C518Test Method for Steady-State Thermal Transmission
1.3 Since this practice is designed for reproducible product
Properties by Means of the Heat Flow Meter Apparatus
comparison, it measuresthethermalresistanceofaninsulation
C653Guide for Determination of theThermal Resistance of
material which has been preconditioned to a relatively dry
Low-Density Blanket-Type Mineral Fiber Insulation
state. Consideration of changes of thermal performance of a
C739Specification for Cellulosic Fiber Loose-Fill Thermal
hygroscopic insulation by sorption of water is beyond the
Insulation
scope of this practice.
C1045Practice for Calculating Thermal Transmission Prop-
erties Under Steady-State Conditions
1.4 The sample preparation techniques outlined in this
C1114Test Method for Steady-State Thermal Transmission
practicedonotcoverthecharacterizationofloose-fillmaterials
Properties by Means of the Thin-Heater Apparatus
intended for enclosed applications. For those applications, a
C1363Test Method for Thermal Performance of Building
separate sample preparation technique that simulates the in-
Materials and Envelope Assemblies by Means of a Hot
stalled condition will be required. However, even for those
Box Apparatus
applications,someotheraspectsofthispracticeareapplicable.
C1373Practice for Determination of Thermal Resistance of
1.5 The values stated in SI units are to be regarded as the
Attic Insulation Systems Under Simulated Winter Condi-
standard. The values given in parentheses are for information
tions
only.
1.6 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Unless otherwise stated, the terms and definitions found
responsibility of the user of this standard to establish appro-
in Terminology C168 are applicable herein.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Significance and Use
1.7 This international standard was developed in accor-
4.1 The thermal resistance, R, of an insulation is used to
dance with internationally recognized principles on standard-
describe its thermal performance.
This practice is under the jurisdiction of ASTM Committee C16 on Thermal
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal
Measurement. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2018. Published October 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1971. Last previous edition approved in 2017 as C687–17. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C0687-18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C687 − 18
4.2 The thermal resistance of an insulation is related to the any thickness from the thermal resistivity obtained from tests
density and thickness of the insulation. It is desirable to obtain on the product at the minimum test thickness (see 4.7.1) and at
test data on thermal resistances at thicknesses and densities the density expected for the proposed thickness.
related to the end uses of the product.
4.9 In principle, any of the standard methods for the
determination of thermal resistance are suitable for loose-fill
4.3 In normal use, the thickness of these products range
from less than 100 mm (4 in.) to greater than 500 mm (20 in.). products.TheseincludeTestMethodsC177,C518, C1114,and
C1363. Of these test methods, the heat flow meter apparatus,
Installed densities depend upon the product type, the installed
thickness, the installation equipment used, the installation Test Method C518, is preferred.
techniques, and the geometry of the insulated space.
4.10 The thermal resistance of low-density insulations de-
4.4 Loose-fill insulations provide coverage information us- pend upon the direction of heat flow. Unless otherwise
specified, tests shall be performed for the maximum heat flow
ingdensitiesselectedbymanufacturerstorepresenttheproduct
settled densities. Generally,itisnecessarytoknowtheproduct condition, that is, a horizontal specimen with heat flow-up.
thermal performance at a representative density. Some cover-
4.11 Specimens shall be prepared in a manner consistent
age charts utilize multiple densities to show that greater
with the intended installation procedure. Products for pneu-
thickness installations usually result in higher installed densi-
matic installation shall be pneumatically applied (blown), and
ties. The use of multiple densities can be detected from the
products for pour-in-place installation shall be poured into
coverage chart by calculating the density for several different
specimen frames.
thermal resistance levels. (The density for a given thermal
4.12 Loosefill insulation installed in attic applications will
resistance can be calculated from the coverage chart by
have heat flow up during the winter. At winter design condi-
dividing the minimum mass per unit area by the minimum
tions in many areas, the winter design temperature difference
thickness.) If the calculated densities are significantly different
will cause convective heat transfer to occur within some
at different thermal resistances, the multiple density strategy
loose-fill insulations. The procedure outlined in Practice C687
has been used.
is not applicable to that measurement unless a Test Method
4.5 When applicable specifications or codes do not specify
C1363testapparatusisusedtoreproducethecorrectboundary
the nominal thermal resistance level to be used for comparison
conditions. To determine how seasonal differences can affect
purposes, a recommended practice is to use the R (met-
si product performance, use Practice C1373. Practice C1373
2 2
ric)=3.3 m K/W (R =19[hft F/Btu]) label density and
IP
measurestheexpectedwinterthermalperformanceofloose-fill
thickness for that measurement.
insulation under simulated winter design temperature condi-
tions and provides specimen requirements necessary for that
4.6 If the density for test purposes is not available from the
determination.
coverage chart, a test density shall be established by use of
applicablespecificationsandcodesor,ifnoneapply,agreement
5. Apparatus
between the requesting body and the testing organization.
5.1 Thermal test apparatus used for this practice shall meet
4.7 Generally, thin sections of these materials are not
these requirements.
uniform. Thus, the test thickness must be greater than or equal
5.1.1 Conformance to Standards—The apparatus shall con-
to the product’s representative thickness if the results are to be
form to all requirements of the ASTM thermal test method
consistent and typical of use.
used.
NOTE 1—The representative thickness is specific for each product and
5.1.2 Size and Error—The apparatus shall be capable of
is determined by running a series of tests in which the density is held
testing specimens up to at least 150-mm (6-in.) thickness with
constant but the thickness is increased. The representative thickness is
an estimated error not greater than 1% attributed to thickness/
defined here as that thickness above which there is no more than a 2%
guard dimensions. (Parametric studies using a mathematical
change in the resistivity of the product. The representative thickness is a
functionofproductblowndensity.Ingeneral,asthedensitydecreases,the
model of the proposed apparatus will give insight to this
representative thickness increases. Fortunately, most products are de-
evaluation. For example see Table1 in the 1976 revision of
signed to be blown over a small range of densities. This limited range
Test Method C518. )
yields a range of representative thicknesses between 100 to 200 mm (4 to
8 in.) for most products. To simplify the process for this Practice, the
NOTE 2—Thermal test apparatus in use for this practice have overall
representative thickness for the C687 tests shall be determined at the
plate dimensions of 457 to 1220 mm (18 to 48 in.) square with metering
midpoint of the blown density range. Once this is accomplished, all
areas 152 to 457 mm (6 to 18 in.) square. Other sizes are acceptable if
thermal testing on this product is conducted at a thickness that is greater
proper consideration of the size-thickness restrictions as outlined in the
or equal to the representative thickness.
test method are observed in their design. (See Practice C1045 for
additional discussion.)
4.7.1 For this practice, the minimum test thickness shall be
5.1.3 Temperature—As a minimum, the apparatus shall be
100 mm (4 in.) or the representative thickness, whichever is
larger. If the test is to represent an installation at a lesser capableoftestingatameantemperatureof23.9°C(75°F)with
a temperature difference of 20 to 28°C (36 to 50°F). The
thickness, the installed thickness shall be used.
4.8 Because of the high cost of construction and operation
of large test equipment, it is impractical to test at the higher
See Table1, “Maximum Spacing Between Warm and Cold Plates of Heat
thicknesses at which products are used. For purposes of this
Flowmeter Apparatus,” of Test Method C518–76 published in 1985 Annual Book
practice, it is acceptable to estimate the thermal resistance at of ASTM Standards, Vol 04.06.
C687 − 18
NOTE 1—Dimensions to match thermal test apparatus.
FIG. 1 Rigid Test Frame
equipment shall be calibrated at the same temperatures as the Choose the combination of hopper, blower, and hose size and
test conditions. Some existing test apparatus have been de- length that is representative of common use for the application
signed to provide measurements over a range of mean tem- of the material to be tested. The following machine specifica-
peraturesfrom−20to55°C(−4to131°F)andforawiderrange tions have been developed for use with mineral wool and
of temperature differences. cellulosic materials.
5.1.4 Humidity—The absolute humidity within the test ap- 5.2.1.1 Mineral Fiber Insulations:
paratus shall be maintained low enough to prevent condensa- (1)Blowing Machine—A commercial blowing machine
tion within the specimen or on the cold plate(s). A maximum with a design capacity for delivering the subject material at a
9°C (48°F) dew point is consistent with the recommended rate between 4 and 15 kg (9 to 33 lb)/min.
material conditioning levels. (2)BlowingHose—Themachineshallutilize46m(150ft)
5.1.5 OrientationandDirectionofHeatFlow—Thethermal oftypical75to100mm(3to4in.)diameterflexible,internally
test apparatus shall be capable of testing horizontal specimens corrugated blowing hose. At least 30 m (100 ft) of the hose
withheatflow-up.Thisorientationrepresentsthemostadverse shall be elevated between 3 and 6 m (10 and 20 ft) above the
heat flow condition for testing between two solid boundaries. outlet of the blowing machine to simulate a typical installation
5.1.6 Thermal Test Specimen Frame—The test frame shall configuration. The hose shall have no more than eight 90°
be sized to match the test apparatus and shall be made of bends and all bends shall be greater than 1.2-m (4-ft) radius.
materials having low thermal conductivity (<0.12W/m K) and Before each sample preparation session, examine the hose for
minimum thickness. A thin, thermally insignificant, screen or materialremainingfrompreviousblows.Dislodgeanyremain-
membrane is stretched across the bottom to support the ing material by mechanically agitating the hose when the
material. Frames have fixed rigid sides or fold-down, machine is running. Repeat as necessary to maintain a clean
collapsible, or compressible sides (see Fig. 1 and Fig. 2). hose for each specimen.
5.2 Specimen Preparation Equipment: NOTE3—Incaseofdispute,formineralfiberinsulationsa75mm(3in.)
hose shall be used to prepare the specimens.
5.2.1 Blowing Machine—A blowing apparatus is required
when pneumatically applied specimens are to be tested. 5.2.1.2 Cellulosic Insulations:
C687 − 18
FIG. 2 Collapsible Test Frame (an Example)
(1)Blowing Machine—Use commercial blowing equip- shall determine the test area weight to within 0.5%.Asecond
ment designed for cellulosic material, that is, hopper, blower, device is required during sample preparation and conditioning
and 30 m (100 ft) of typical 50 to 75 mm (2 to 3 in.) diameter to determine the sample plus frame weight. This device shall
hose. determine the combined weight to within 0.5%.
(2)Settled Density Catch Containers—Containers shall be
5.2.4 Conditioning Room—An enclosure held at near con-
sizedtomatchthetestframesandshallbemadeofplywoodor
stant temperature and humidity is required to stabilize the
similar materials. A thin sheet of plywood attached across the
materials or products prior to testing. The conditions are
bottom supports the insulation. Frames shall have fixed sides.
generallygiveninproductspecificationsorinotherappropriate
documents. In the absence of specific directions, conditioning
NOTE 4—In case of dispute, for cellulosic insulations a 51 mm (2 in.)
shall be carried out in an atmosphere of 23 6 2°C (75 6 4°F)
hose shall be used to prepare the specimens
and a relative humidity not greater than 45% (see 5.1.4).
5.2.2 Test Area Specimen Cutter—Ameans for isolating the
5.2.5 Specimen Support Sheet—Astiff cardboard or equiva-
material within the metering area is required for the density
lent sheet to be used to support the specimen during
determination.Theisolatedregionshallhaveanareaandshape
preparation, conditioning, and transport.
identical to the metering area. Fig. 3 provides an example of a
diecutterusedforthispurpose.Theuseofacompressionplate 5.2.6 Specimen Preparation Room—A semi-enclosed area
to compress an area larger than the metering area, prior to where the test material is blown into the specimen frame is
meteringareamaterialremovalisrecommended.Thecompres- required. This enclosure protects the blowing operation from
sion plate shall extend at least 75 mm (3 in.) beyond the wind or strong air currents. The room size shall not influence
metering area boundary. the blowing stream from the hose. Minimum room dimensions
5.2.3 Weighing Devices—A device is required to weigh the of3by3by2.5m(10by10by8ft)aregenerallyadequatefor
testareamaterialafterthethermaltestiscomplete.Thisdevice this purpose. Experience has shown that, to obtain uniform
C687 − 18
6. Sampling
6.1 Sampling plans given in the material specifications,
regulations, or other appropriate documents shall be followed
when applicable. In the absence of such directions, material
fromatleasttworandomlychosenpackagesshallbecombined
in equal portions (weight) and placed in the blowing machine
so as to combine materials as uniformly as practicable.
Alternatively, multiple tests are performed where each speci-
men is made from a single package.
6.2 The insulation material shall be preconditioned at labo-
ratory conditions (see 5.2.4) prior to the specimen blowing, if
necessary, to remove excess moisture added during the manu-
facturing process. Preconditioning of materials not only en-
sures controlled blowing conditions but reduces the time
required to condition the prepared specimen prior to thermal
testing. For cellulosic materials, the preconditioning guideline
is defined in Specification C739.
7. Specimen Preparation
7.1 Pneumatic Application—General Materials:
7.1.1 Theproceduredescribedinthissectionisintendedfor
products which are normally installed pneumatically which do
not exhibit settling under normal installed conditions. Use 7.2
forpneumaticallyinstalledproductswherethespecimenprepa-
ration is modified to accommodate a correction for settling
after installation.
NOTE 5—For commonly available loose-fill insulations, state and
federalenergycodes,ASTMmaterialspecifications,andtheFederalTrade
Commission have identified those materials that apply a correction for
settling when determining thermal performance. It is beyond the scope of
this practice to outline the procedures for this determination.
7.1.2 Thespecimenpreparationroomshallbecleanandfree
Note 1—Use of a pressure plate to compress a loose-fill specimen prior to cut-
of old insulation prior to the start of specimen preparation.
ting the metering area.
NOTE 6—Many factors influence the characteristics of the blown
insulation.These include blowing rate, machine adjustments, the size and
length of the hose, and the angle and dimensions of the hose outlet in
relation to the test frame. Trained operators are required to duplicate
field-installedconditioning.Someusersofthismethodhaveconstructeda
support structure that holds the hose end at the proper orientation. This
removes some of the operator dependency during the blowing operation.
NOTE 7—For ease of specimen preparation, the specimen shall be
blown close to the desired test density. Operators have the option to
establish a target weight of insulation required to fill the test frame as a
controlduringthespecimenpreparationprocess.Byplacingthespecimen
frameandsupportsheetonascaleinthespecimenpreparationroomwhile
blowing occurs, it is possible to fill the container with the mass of the
insulation targeted for the test. Another option is to eliminate these extra
steps. The reported test density, however, is obtained from the metering
area density measurement conducted after the thermal test.
7.1.3 If the specimen is to be blown to a predetermined
density, calculate the target weight of insulation required to fill
the test frame to the target thickness and density. If the intent
Note 2—Use of a hydraulic die cutter to cut the metering area. Note the com-
is to test the material at whatever density is blown, then this
pressed specimen after using the pressure plate.
calculation is not required.
7.1.4 Assembletheblowingmachine,hose,andhoselength
FIG. 3 Test Area Cutter
combinationasappropriateforthematerialbeingprepared(see
specimens, it is necessary to blow an area greater than the recommendations in 5.2.1.1).
dimensions of the specimen frame. The recommended area to 7.1.5 Set the blowing machine adjustments and select the
be covered is at least 2.5 times the minimum test frame feed rates in accordance with the insulation manufacturer’s
dimension. recommendations. If the insulation manufacturer does not
C687 − 18
providethisinformation,consultthemachinemanufacturerfor 7.1.14 Remove the surrounding excess material from the
recommended settings. Record the machine settings used. area of the test frame. Move the specimen frame and support
sheet to a flat level table.
7.1.6 Place at least two packages (see 6.1) of the insulation
7.1.15 Remove excess material to reach a level thickness
material into the blowing machine hopper. If the hopper is too
that is no greater than 115% of target test thickness. Do not
small to hold two packages of material, fill the hopper to
disturb the remaining material, preserving it in the as-blown
capacity with equal portions of material from two packages.
condition.
7.1.7 Place the thermal specimen holder on the specimen
7.1.16 Move the specimen frame and its accompanying
support sheet in the center of the specimen preparation area
support sheet to the specimen conditioning room.
(see Note 7).
7.1.17 Condition the specimen and frame for sufficient time
7.1.8 Turn on the blowing machine with the hose outlet
to reach constant weight (less than 1.0% weight change in 24
directed away from the test specimen frame. Do not blow the
h).
thermaltestspecimenuntilasteadyflowofinsulationmaterial
has been achieved.
7.2 Pneumatic Application—Settled Density Method:
7.2.1 This method is intended for pneumatically installed
7.1.9 Oncesteadyflowisachieved,(approximately30to45
s), direct the hose outlet toward the test specimen frame. The productswherethespecimenpreparationismodifiedtoaccom-
modate a correction for settling after installation.
hoseoutletshallbehorizontalandataheightabovethebottom
ofthetestspecimenframeofnolessthan0.9mandnogreater
NOTE 11—Although this section is specific to cellulosic insulations, the
than 1.2 m (3 to 4 ft). This height is measured from the
principles outlined are used for other insulations requiring correction for
centerline of the hose opening.
settled density, providing that the appropriate blowing equipment and
settling simulation method (see 7.2.13) is used. Reference shall be made
7.1.10 The end of the loose-fill trajectory falls beyond the
to the appropriate material specification to make this determination.
test specimen frame at the start of the blow.The operator shall
slowly step back, allowing the end of the trajectory to fall into 7.2.2 Assembletheblowingmachine,hose,andhoselength
combination as appropriate for the insulation material being
the specimen frame.While continuing to back up, the operator
slowly changes the direction of the hose approximately 645° prepared. (See recommendations in 5.2.1.2.)
in a horizontal plane to uniformly fill the test specimen frame. 7.2.3 With the blower turned off, turn o
...

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: C687 − 17 C687 − 18
Standard Practice for
Determination of Thermal Resistance of Loose-Fill Building
Insulation
This standard is issued under the fixed designation C687; 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 practice presents a laboratory guide to determine the thermal resistance of loose-fill building insulations at mean
temperatures between −20 and 55°C (−4 to 131°F).
1.2 This practice applies to a wide variety of loose-fill thermal insulation products including but not limited to fibrous glass,
rock/slag wool, or cellulosic fiber materials; granular types including vermiculite and perlite; pelletized products; and any other
insulation material installed pneumatically or poured in place. It does not apply to products that change their character after
installation either by chemical reaction or the application of binders or adhesives, nor does it consider the effects of structures,
containments, facings, or air films.
1.3 Since this practice is designed for reproducible product comparison, it measures the thermal resistance of an insulation
material which has been preconditioned to a relatively dry state. Consideration of changes of thermal performance of a hygroscopic
insulation by sorption of water is beyond the scope of this practice.
1.4 The sample preparation techniques outlined in this practice do not cover the characterization of loose-fill materials intended
for enclosed applications. For those applications, a separate sample preparation technique that simulates the installed condition will
be required. However, even for those applications, some other aspects of this practice are applicable.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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:
C167 Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations
C168 Terminology Relating to Thermal Insulation
C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus
C518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
C653 Guide for Determination of the Thermal Resistance of Low-Density Blanket-Type Mineral Fiber Insulation
C739 Specification for Cellulosic Fiber Loose-Fill Thermal Insulation
C1045 Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
C1114 Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus
C1363 Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
C1373 Practice for Determination of Thermal Resistance of Attic Insulation Systems Under Simulated Winter Conditions
This practice is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal Measurement.
Current edition approved March 15, 2017Sept. 1, 2018. Published April 2017October 2018. Originally approved in 1971. Last previous edition approved in 20122017 as
C687 – 12.C687 – 17. DOI: 10.1520/C0687-17.10.1520/C0687-18.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C687 − 18
3. Terminology
3.1 Unless otherwise stated, the terms and definitions found in Terminology C168 are applicable herein.
4. Significance and Use
4.1 The thermal resistance, R, of an insulation is used to describe its thermal performance.
4.2 The thermal resistance of an insulation is related to the density and thickness of the insulation. It is desirable to obtain test
data on thermal resistances at thicknesses and densities related to the end uses of the product.
4.3 In normal use, the thickness of these products range from less than 100 mm (4 in.) to greater than 500 mm (20 in.). Installed
densities depend upon the product type, the installed thickness, the installation equipment used, the installation techniques, and the
geometry of the insulated space.
4.4 Loose-fill insulations provide coverage information using densities selected by manufacturers to represent the product
settled densities. Generally, it is necessary to know the product thermal performance at a representative density. Some coverage
charts utilize multiple densities to show that greater thickness installations usually result in higher installed densities. The use of
multiple densities can be detected from the coverage chart by calculating the density for several different thermal resistance levels.
(The density for a given thermal resistance can be calculated from the coverage chart by dividing the minimum mass per unit area
by the minimum thickness.) If the calculated densities are significantly different at different thermal resistances, the multiple
density strategy has been used.
4.5 When applicable specifications or codes do not specify the nominal thermal resistance level to be used for comparison
2 2
purposes, a recommended practice is to use the R (metric) = 3.3 m K/W (R = 19 [h ft F/Btu]) label density and thickness for
si IP
that measurement.
4.6 If the density for test purposes is not available from the coverage chart, a test density shall be established by use of
applicable specifications and codes or, if none apply, agreement between the requesting body and the testing organization.
4.7 Generally, thin sections of these materials are not uniform. Thus, the test thickness must be greater than or equal to the
product’s representative thickness if the results are to be consistent and typical of use.
NOTE 1—The representative thickness is specific for each product and is determined by running a series of tests in which the density is held constant
but the thickness is increased. The representative thickness is defined here as that thickness above which there is no more than a 2 % change in the
resistivity of the product. The representative thickness is a function of product blown density. In general, as the density decreases, the representative
thickness increases. Fortunately, most products are designed to be blown over a small range of densities. This limited range yields a range of representative
thicknesses between 100 to 200 mm (4 to 8 in.) for most products. To simplify the process for this Practice, the representative thickness for the C687
tests shall be determined at the midpoint of the blown density range. Once this is accomplished, all thermal testing on this product is conducted at a
thickness that is greater or equal to the representative thickness.
4.7.1 For this practice, the minimum test thickness shall be 100 mm (4 in.) or the representative thickness, whichever is larger.
If the test is to represent an installation at a lesser thickness, the installed thickness shall be used.
4.8 Because of the high cost of construction and operation of large test equipment, it is impractical to test at the higher
thicknesses at which products are used. For purposes of this practice, it is acceptable to estimate the thermal resistance at any
thickness from the thermal resistivity obtained from tests on the product at the minimum test thickness (see 4.7.1) and at the density
expected for the proposed thickness.
4.9 In principle, any of the standard methods for the determination of thermal resistance are suitable for loose-fill products.
These include Test Methods C177, C518, C1114, and C1363. Of these test methods, the heat flow meter apparatus, Test Method
C518, is preferred because of its lower cost and shorter testing time.preferred.
4.10 The thermal resistance of low-density insulations depend upon the direction of heat flow. Unless otherwise specified, tests
shall be performed for the maximum heat flow condition, that is, a horizontal specimen with heat flow-up.
4.11 Specimens shall be prepared in a manner consistent with the intended installation procedure. Products for pneumatic
installation shall be pneumatically applied (blown), and products for pour-in-place installation shall be poured into specimen
frames.
4.12 Loosefill insulation installed in attic applications will have heat flow up during the winter. At winter design conditions in
many areas, the winter design temperature difference will cause convective heat transfer to occur within some loose-fill insulations.
The procedure outlined in Practice C687 is not applicable to that measurement unless a Test Method C1363 test apparatus is used
to reproduce the correct boundary conditions. To determine how seasonal differences can affect product performance, use Practice
C1373. Practice C1373 measures the expected winter thermal performance of loose-fill insulation under simulated winter design
temperature conditions and provides specimen requirements necessary for that determination.
5. Apparatus
5.1 Thermal test apparatus used for this practice shall meet these requirements.
5.1.1 Conformance to Standards—The apparatus shall conform to all requirements of the ASTM thermal test method used.
C687 − 18
5.1.2 Size and Error—The apparatus shall be capable of testing specimens up to at least 150-mm (6-in.) thickness with an
estimated error not greater than 1 % attributed to thickness/guard dimensions. (Parametric studies using a mathematical model of
the proposed apparatus will give insight to this evaluation. For example see Table 1 in the 1976 revision of Test Method C518. )
NOTE 2—Thermal test apparatus in use for this practice have overall plate dimensions of 457 to 1220 mm (18 to 48 in.) square with metering areas
152 to 457 mm (6 to 18 in.) square. Other sizes are acceptable if proper consideration of the size-thickness restrictions as outlined in the test method are
observed in their design. (See Practice C1045 for additional discussion.)
5.1.3 Temperature—As a minimum, the apparatus shall be capable of testing at a mean temperature of 23.9°C (75°F) with a
temperature difference of 20 to 28°C (36 to 50°F). The equipment shall be calibrated at the same temperatures as the test
conditions. Some existing test apparatus have been designed to provide measurements over a range of mean temperatures from −20
to 55°C (−4 to 131°F) and for a wider range of temperature differences.
5.1.4 Humidity—The absolute humidity within the test apparatus shall be maintained low enough to prevent condensation within
the specimen or on the cold plate(s). A maximum 9°C (48°F) dew point is consistent with the recommended material conditioning
levels.
5.1.5 Orientation and Direction of Heat Flow—The thermal test apparatus shall be capable of testing horizontal specimens with
heat flow-up. This orientation represents the most adverse heat flow condition for testing between two solid boundaries.
5.1.6 Thermal Test Specimen Frame—The test frame shall be sized to match the test apparatus and shall be made of materials
having low thermal conductivity (<0.12 W/m K) and minimum thickness. A thin, thermally insignificant, screen or membrane is
stretched across the bottom to support the material. Frames have fixed rigid sides or fold-down, collapsible, or compressible sides
(see Fig. 1 and Fig. 2).
5.2 Specimen Preparation Equipment:
NOTE 1—Dimensions to match thermal test apparatus.
FIG. 1 Rigid Test Frame
See Table 1, “Maximum Spacing Between Warm and Cold Plates of Heat Flowmeter Apparatus,” of Test Method C518 – 76 published in 1985 Annual Book of ASTM
Standards, Vol 04.06.
C687 − 18
FIG. 2 Collapsible Test Frame (an Example)
5.2.1 Blowing Machine—A blowing apparatus is required when pneumatically applied specimens are to be tested. Choose the
combination of hopper, blower, and hose size and length that is representative of common use for the application of the material
to be tested. The following machine specifications have been developed for use with mineral wool and cellulosic materials.
5.2.1.1 Mineral Fiber Insulations:
(1) Blowing Machine—A commercial blowing machine with a design capacity for delivering the subject material at a rate
between 4 and 15 kg (9 to 33 lb)/min.
(2) Blowing Hose—The machine shall utilize 46 m (150 ft) of typical 75 to 100 mm (3 to 4 in.) diameter flexible, internally
corrugated blowing hose. At least 30 m (100 ft) of the hose shall be elevated between 3 and 6 m (10 and 20 ft) above the outlet
of the blowing machine to simulate a typical installation configuration. The hose shall have no more than eight 90° bends and all
bends shall be greater than 1.2-m (4-ft) radius. Before each sample preparation session, examine the hose for material remaining
from previous blows. Dislodge any remaining material by mechanically agitating the hose when the machine is running. Repeat
as necessary to maintain a clean hose for each specimen.
NOTE 3—In case of dispute, for mineral fiber insulations a 75 mm (3 in.) hose shall be used to prepare the specimens.
5.2.1.2 Cellulosic Insulations:
(1) Blowing Machine—Use commercial blowing equipment designed for cellulosic material, that is, hopper, blower, and 30 m
(100 ft) of typical 50 to 75 mm (2 to 3 in.) diameter hose.
(2) Settled Density Catch Containers—Containers shall be sized to match the test frames and shall be made of plywood or
similar materials. A thin sheet of plywood attached across the bottom supports the insulation. Frames shall have fixed sides.
NOTE 4—In case of dispute, for cellulosic insulations a 51 mm (2 in.) hose shall be used to prepare the specimens
C687 − 18
5.2.2 Test Area Specimen Cutter—A means for isolating the material within the metering area is required for the density
determination. The isolated region shall have an area and shape identical to the metering area. Fig. 3 provides an example of a die
Note 1—Use of a pressure plate to compress a loose-fill specimen prior to cut-
ting the metering area.
Note 2—Use of a hydraulic die cutter to cut the metering area. Note the com-
pressed specimen after using the pressure plate.
FIG. 3 Test Area Cutter
C687 − 18
cutter used for this purpose. The use of a compression plate to compress an area larger than the metering area, prior to metering
area material removal is recommended. The compression plate shall extend at least 75 mm (3 in.) beyond the metering area
boundary.
5.2.3 Weighing Devices—A device is required to weigh the test area material after the thermal test is complete. This device shall
determine the test area weight to within 0.5 %. A second device is required during sample preparation and conditioning to
determine the sample plus frame weight. This device shall determine the combined weight to within 0.5 %.
5.2.4 Conditioning Room—An enclosure held at near constant temperature and humidity is required to stabilize the materials
or products prior to testing. The conditions are generally given in product specifications or in other appropriate documents. In the
absence of specific directions, conditioning shall be carried out in an atmosphere of 23 6 2°C (75 6 4°F) and a relative humidity
not greater than 45 % (see 5.1.4).
5.2.5 Specimen Support Sheet—A stiff cardboard or equivalent sheet to be used to support the specimen during preparation,
conditioning, and transport.
5.2.6 Specimen Preparation Room—A semi-enclosed area where the test material is blown into the specimen frame is required.
This enclosure protects the blowing operation from wind or strong air currents. The room size shall not influence the blowing
stream from the hose. Minimum room dimensions of 3 by 3 by 2.5 m (10 by 10 by 8 ft) are generally adequate for this purpose.
Experience has shown that, to obtain uniform specimens, it is necessary to blow an area greater than the dimensions of the
specimen frame. The recommended area to be covered is at least 2.5 times the minimum test frame dimension.
6. Sampling
6.1 Sampling plans given in the material specifications, regulations, or other appropriate documents shall be followed when
applicable. In the absence of such directions, material from at least two randomly chosen packages shall be combined in equal
portions (weight) and placed in the blowing machine so as to combine materials as uniformly as practicable. Alternatively, multiple
tests are performed where each specimen is made from a single package.
6.2 The insulation material shall be preconditioned at laboratory conditions (see 5.2.4) prior to the specimen blowing, if
necessary, to remove excess moisture added during the manufacturing process. Preconditioning of materials not only ensures
controlled blowing conditions but reduces the time required to condition the prepared specimen prior to thermal testing. For
cellulosic materials, the preconditioning guideline is defined in Specification C739.
7. Specimen Preparation
7.1 Pneumatic Application—General Materials:
7.1.1 The procedure described in this section is intended for products which are normally installed pneumatically which do not
exhibit settling under normal installed conditions. Use 7.2 for pneumatically installed products where the specimen preparation is
modified to accommodate a correction for settling after installation.
NOTE 5—For commonly available loose-fill insulations, state and federal energy codes, ASTM material specifications, and the Federal Trade
Commission have identified those materials that apply a correction for settling when determining thermal performance. It is beyond the scope of this
practice to outline the procedures for this determination.
7.1.2 The specimen preparation room shall be clean and free of old insulation prior to the start of specimen preparation.
NOTE 6—Many factors influence the characteristics of the blown insulation. These include blowing rate, machine adjustments, the size and length of
the hose, and the angle and dimensions of the hose outlet in relation to the test frame. Trained operators are required to duplicate field-installed
conditioning. Some users of this method have constructed a support structure that holds the hose end at the proper orientation. This removes some of the
operator dependency during the blowing operation.
NOTE 7—For ease of specimen preparation, the specimen shall be blown close to the desired test density. Operators have the option to establish a target
weight of insulation required to fill the test frame as a control during the specimen preparation process. By placing the specimen frame and support sheet
on a scale in the specimen preparation room while blowing occurs, it is possible to fill the container with the mass of the insulation targeted for the test.
Another option is to eliminate these extra steps. The reported test density, however, is obtained from the metering area density measurement conducted
after the thermal test.
7.1.3 If the specimen is to be blown to a predetermined density, calculate the target weight of insulation required to fill the test
frame to the target thickness and density. If the intent is to test the material at whatever density is blown, then this calculation is
not required.
7.1.4 Assemble the blowing machine, hose, and hose length combination as appropriate for the material being prepared (see
recommendations in 5.2.1.1).
7.1.5 Set the blowing machine adjustments and select the feed rates in accordance with the insulation manufacturer’s
recommendations. If the insulation manufacturer does not provide this information, consult the machine manufacturer for
recommended settings. Record the machine settings used.
7.1.6 Place at least two packages (see 6.1) of the insulation material into the blowing machine hopper. If the hopper is too small
to hold two packages of material, fill the hopper to capacity with equal portions of material from two packages.
7.1.7 Place the thermal specimen holder on the specimen support sheet in the center of the specimen preparation area (see Note
7).
C687 − 18
7.1.8 Turn on the blowing machine with the hose outlet directed away from the test specimen frame. Do not blow the thermal
test specimen until a steady flow of insulation material has been achieved.
7.1.9 Once steady flow is achieved, (approximately 30 to 45 s), direct the hose outlet toward the test specimen frame. The hose
outlet shall be horizontal and at a height above the bottom of the test specimen frame of no less than 0.9 m and no greater than
1.2 m (3 to 4 ft). This height is measured from the centerline of the hose opening.
7.1.10 The end of the loose-fill trajectory falls beyond the test specimen frame at the start of the blow. The operator shall slowly
step back, allowing the end of the trajectory to fall into the specimen frame. While continuing to back up, the operator slowly
changes the direction of the hose approximately 645° in a horizontal plane to uniformly fill the test specimen frame. The operator
continues to make passes back and forth until the specimen frame is filled to approximately one half of the target thickness.
7.1.11 When the test specimen frame is approximately one half full, point the hose away from the test frame and stop the
blowing machine. Remove all excess insulation from around the test frame, being careful not to disturb the insulation inside.
Carefully rotate the test frame and support sheet 180° from their original position. Do not jar the frame or cause any unnecessary
settling of the insulation. During handling of the blown specimen, keep the support sheet firmly against the bottom of the specimen
frame.
NOTE 8—For some insulation materials, it is not necessary to rotate the specimen frame during blowing in order to prepare a uniform specimen.
However, in case of dispute, the specimen preparation procedure listed, herein, shall be followed.
7.1.12 Restart the blowing machine, establish flow as in 7.1.8, and continue to fill the test specimen frame.
7.1.13 Continue blowing the material into the test frame until it is uniformly full and there is a slight excess above the target
test thickness. Do not exceed 20 % excess thickness while blowing. For specimen preparation controlled by weight, the control
must be a ma
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