ASTM C916-20

Standard Specification for Adhesives for Duct Thermal Insulation

ABSTRACT
This specification covers minimum material requirements, and safety precautions in application, for adhesives to bond thermal insulation duct liner on the interior surfaces of sheet metal air conditioning ducts; and for coating exposed edges and joints of duct liner thermal insulation to minimize erosion of insulation fibers by air movement. Adhesives shall be classified as follows: Type I; Type II; Type III; and Type IV. The following test methods shall be performed: bonding strength; bond retention after heat aging; flame spread and smoke developed; edge-burning test; storage stability; and precision and bias.
SCOPE
1.1 This specification covers minimum material requirements, and safety precautions in application, for adhesives to bond thermal insulation duct liner on the interior surfaces of sheet metal air conditioning ducts; and for coating exposed edges and joints of duct liner thermal insulation to minimize erosion of insulation fibers by air movement.  
1.2 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.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Sections 7 and 9.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 29-Feb-2020
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.33 - Insulation Finishes and Moisture

Relations

• Replaces: ASTM C916-14 - Standard Specification for Adhesives for Duct Thermal Insulation
• Effective Date: 01-Mar-2020
• Refers: ASTM C168-24 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2024
• Refers: ASTM E84-23d - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Dec-2023
• Refers: ASTM E84-23c - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Sep-2023
• Refers: ASTM D93-20 - Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
• Effective Date: 01-Aug-2020
• Refers: ASTM E84-19b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM E84-19a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 15-Apr-2019
• Refers: ASTM E84-19 - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Mar-2019
• Refers: ASTM E84-18b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Oct-2018
• Refers: ASTM E84-18a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2018
• Refers: ASTM C168-18 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2018
• Refers: ASTM E84-18 - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Mar-2018
• Refers: ASTM E84-17a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Nov-2017
• Refers: ASTM D903-98(2017) - Standard Test Method for Peel or Stripping Strength of Adhesive Bonds
• Effective Date: 01-Nov-2017
• Refers: ASTM E84-17 - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Aug-2017

Overview

ASTM C916-20: Standard Specification for Adhesives for Duct Thermal Insulation sets forth the minimum material requirements and safety precautions for adhesives used in bonding thermal insulation duct liners to the interior surfaces of sheet metal air conditioning ducts. This standard also covers the use of adhesives for coating exposed edges and joints of duct liner insulation, specifically to minimize erosion of insulation fibers caused by air movement. Its comprehensive requirements help ensure reliable performance, fire safety, and compliance in HVAC duct insulation installations.

Key Topics

• Adhesive Application and Performance

  • Coverage of adhesives applied to interior duct surfaces and exposed insulation edges/joints
  • Essential for minimizing fiber erosion, promoting durability and safety in HVAC systems

• Adhesive Classification

  • Four adhesive types based on flammability and fire-resistant properties:
    • Type I: Nonflammable, passes edge-burning test
    • Type II: Nonflammable, does not pass edge-burning test
    • Type III: Flammable, passes edge-burning test
    • Type IV: Flammable, does not pass edge-burning test

• Testing and Quality Requirements

  • Bonding strength (under standard, humid, and heated conditions)
  • Bond retention after heat aging
  • Flame spread and smoke developed (per ASTM E84)
  • Edge-burning tests for specific types
  • Storage stability for at least 6 months
  • Additional considerations: viscosity, bonding time, solids content, color, and odor (as mutually agreed)

• Safety and Labeling

  • Explicit safety instructions and threshold limit value (TLV) labeling for volatile solvent content
  • Special precautions for Types III and IV adhesives due to flammability
  • Requirements for marking containers with type, manufacturer, content, use instructions, and safety information

Applications

• HVAC Ductwork

  • Used to bond thermal insulation duct liners directly to the interior surfaces of metal air conditioning ducts in residential, commercial, and industrial buildings

• Insulation Edge Sealing

  • Applied to exposed edges and joints of insulation to reduce fiber loss caused by air movement through ducts

• Fire-Safe Installations

  • Ensures that insulation adhesives meet critical flammability standards, reducing fire hazards and meeting code requirements for building materials

• Quality Control in Manufacturing and Construction

  • Provides test methods for strength, durability, and fire safety, supporting both project specification and quality assurance

Related Standards

• ASTM C168: Terminology Relating to Thermal Insulation
• ASTM D93: Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
• ASTM D903: Test Method for Peel or Stripping Strength of Adhesive Bonds
• ASTM D1151: Practice for Effect of Moisture and Temperature on Adhesive Bonds
• ASTM E84: Test Method for Surface Burning Characteristics of Building Materials
• NFPA No. 30: Flammable and Combustible Liquids Code
• SMACNA Duct Liner Application Standard: Guidance on duct liner installation
• ACGIH Threshold Limit Values: Inhalation exposure limits for workplace safety

Practical Value

The use of adhesives conforming to ASTM C916-20 delivers improved indoor air quality, consistent insulation performance, and enhanced fire safety in HVAC systems. Specification of this standard in project documents ensures compliance with industry best practices, regulatory requirements, and effective risk management in duct thermal insulation installations. Using ASTM-compliant adhesives also supports long-term HVAC efficiency and reliability while safeguarding installer and occupant safety.

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: C916 −20
Standard Specification for
Adhesives for Duct Thermal Insulation
This standard is issued under the fixed designation C916; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope E84 Test Method for Surface Burning Characteristics of
Building Materials
1.1 This specification covers minimum material
requirements, and safety precautions in application, for adhe- 2.2 Other Standards:
sives to bond thermal insulation duct liner on the interior NFPA No. 30, Flammable and Combustible Liquids Code
surfaces of sheet metal air conditioning ducts; and for coating SMACNA Duct Liner Application Standard
exposed edges and joints of duct liner thermal insulation to ACGIH Threshold Limit Values
minimize erosion of insulation fibers by air movement.
3. Terminology
1.2 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical 3.1 Definitions:
conversions to SI units that are provided for information only
3.1.1 threshold limit value (TLV)—the concentration in
and are not considered standard. parts of vapor per million parts of air, by volume at 25°C and
101.3 kPa (1 atm) pressure. This value is an indication of the
1.3 This standard does not purport to address all of the
relative inhalation toxicity hazard of vapors from volatile
safety concerns, if any, associated with its use. It is the
solvents used in adhesives. Data on TLV of materials are
responsibility of the user of this standard to establish appro-
published annually by ACGIH.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.1.2 For definitions of other terms on thermal insulating
For specific precautionary statements, see Sections 7 and 9.
materials used in this specification, see Terminology C168.
1.4 This international standard was developed in accor-
3.2 Definitions of Terms Specific to This Standard:
dance with internationally recognized principles on standard-
3.2.1 flammable vehicle—in an adhesive, the liquid portion
ization established in the Decision on Principles for the
having a flash point as determined by Test Methods D93.
Development of International Standards, Guides and Recom-
3.2.2 nonflammable vehicle— in an adhesive, the liquid
mendations issued by the World Trade Organization Technical
portion having no flash point as determined by Test Methods
Barriers to Trade (TBT) Committee.
D93.
2. Referenced Documents
4. Classification of Adhesives
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation 4.1 Adhesives supplied under this specification are classi-
D93 Test Methods for Flash Point by Pensky-Martens fied as follows:
Closed Cup Tester
4.1.1 Type I—An adhesive in which the vehicle is nonflam-
D903 Test Method for Peel or Stripping Strength of Adhe- mable in the liquid (wet) state and which will pass the
sive Bonds
edge-burning test of 6.2.
D1151 Practice for Effect of Moisture and Temperature on
4.1.2 Type II—An adhesive in which the vehicle is nonflam-
Adhesive Bonds
mable in the liquid (wet) state and which will not pass the
edge-burning test of 6.2.
This specification is under the jurisdiction of ASTM Committee C16 on
Thermal Insulation and is the direct responsibility of Subcommittee C16.33 on
Insulation Finishes and Moisture.
Current edition approved March 1, 2020. Published March 2020. Originally Available from National Fire Protection Association (NFPA), 1 Batterymarch
approved in 1979. Last previous edition approved in 2014 as C916 – 14. DOI: Park, Quincy, MA 02169-7471, http://www.nfpa.org.
10.1520/C0916-20. Sheet Metal and Air Conditioning Contractors National Assn., 4201 Lafayette
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Center Drive, Chantilly, VA 20151–1219, http://www.smacna.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from American Conference of Governmental Industrial Hygienists,
Standards volume information, refer to the standard’s Document Summary page on Inc. (ACGIH), 1330 Kemper Meadow Dr., Suite 600, Cincinnati, OH 45240,
the ASTM website. http://www.acgih.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C916 − 20
4.1.3 Type III—An adhesive in which the vehicle is flam- 7.2.1 Prepare the specimens in accordance with Test
mable in the liquid (wet) state and which will pass the Method D903. The specimens shall be composed of 18-gage
edge-burning test of 6.2. (0.05-in., 1.3-mm) galvanized steel bonded to 8-oz (0.3-kg/m )
4.1.4 Type IV—An adhesive in which the vehicle is flam- cotton canvas. The galvanized steel shall have been cleaned
mable in the liquid (wet) state and which will not pass the with solvent and dried.
edge-burning test of 6.2. 7.2.2 Apply the adhesive by brushing or spraying in accor-
dance with the manufacturer’s recommendation for thickness.
5. Ordering Information
Apply the adhesive to the metal surface only. As soon as the
applied adhesive has become tacky as determined by finger
5.1 Attentionofthepurchaserisdirectedtothefactthatfour
types of adhesives are available under this specification. If the pressure, bond the canvas to the metal. Immediately after
bonding, roll the canvas with a hand roller weighing 5 lb per
purchaser does not specify which type is desired, the supplier
shallfurnishTypeIonly.Otherpurchaseroptionsaredescribed lineal inch of roller (90 kg/m) (that is, a roller 4 in. long should
have a total weight of 20 lb), to ensure uniform contact
in 6.1.4 and 6.1.5.
between adherends. Condition the specimens for 24 h at a
6. Physical Requirements
relative humidity of 50 6 2 % at 73.4 6 2°F (23 6 1°C). Test
the specimens as described in Test Method D903 except that
6.1 Requirements Applicable to All Types:
the rate of travel of the power-actuated grip of the testing
6.1.1 Bonding Strength—The adhesive shall have a bonding
machine shall be 2 in. (50 mm)/min.
strength of not less than 0.5 lb/in. (9.0 g/mm) of width after
testing under each condition of room temperature, high
7.3 Bonding Strength at High Humidity—Prepare the speci-
humidity, and heating, as specified in 7.2, 7.3, and 7.4.
mensasdescribedin7.2exceptthatafterthe24-hconditioning
6.1.2 Bond Retention After Heat-Aging—Duct liner fiber
period specified, further condition the specimens by exposure
shall remain bonded to at least 75 % of the total area of each
to a relative humidity of 95 % minimum at 73.4 6 2°F (23 6
specimen after testing as specified in 7.5.
1°C) for 24 h. Conduct the testing as specified in Test Method
6.1.3 Flame Spread and Smoke Developed—Adhesive for
D903immediatelyafterremovalofthetestspecimensfromthe
duct liner shall have a fire hazard classification not to exceed
conditioning atmosphere and preferably under the same con-
25 for flame spread and 50 for smoke developed. Classification
ditions. The rate of jaw separation of the testing machine shall
shall be determined by Test Method E84. A report from a
be 2 in. (50 mm)/min.
qualified testing laboratory to indicate that fire hazard classi-
7.4 Bonding Strength at While Heated—Prepare the speci-
fication does not exceed that specified is acceptable.Tests shall
mensasdescribedin7.2exceptthatafterthe24-hconditioning
be conducted as stated in 7.6.
period specified, further condition the specimens for 7 days in
6.1.4 Storage Stability—The adhesive shall meet the re-
acirculatingairovenmaintainedatatemperatureof158 62°F
quirements specified herein after completion of storage for a
(70 6 1°C). Conduct the testing as specified in Test Method
period of 6 months under the conditions specified in 7.8.If
D903 at a temperature of 158 6 2°F (70 6 1°C) at 2 in.
acceptable to the purchaser, and instead of performing a
(50mm)/min jaw separation speed.
storage stability test on each shipment, the manufacturer shall
7.5 Bond Retention After Heat Aging—Prepare a flat piece
provide evidence that previous commercial lots of the adhesive
of 18-gage (0.05-in., 1.3-mm) galvanized steel 6 by 16 in. (150
have met satisfactorily the 6 months storage stability require-
by 400 mm) by cleaning with solvent and drying. Apply the
ment.
adhesive to one side by brushing or spraying in accordance
6.1.5 Other Physical Requirements—Other requirements
with the manufacturer’s recommendation for thickness. As
may be mutually agreed up
...

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: C916 − 14 C916 − 20
Standard Specification for
Adhesives for Duct Thermal Insulation
This standard is issued under the fixed designation C916; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers minimum material requirements, and safety precautions in application, for adhesives to bond
thermal insulation duct liner on the interior surfaces of sheet metal air conditioning ducts; and for coating exposed edges and joints
of duct liner thermal insulation to minimize erosion of insulation fibers by air movement.
1.2 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.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific precautionary statements, see Sections 7 and 9.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D903 Test Method for Peel or Stripping Strength of Adhesive Bonds
D1151 Practice for Effect of Moisture and Temperature on Adhesive Bonds
E84 Test Method for Surface Burning Characteristics of Building Materials
2.2 Other Standards:
NFPA No. 30, Flammable and Combustible Liquids Code
SMACNA Duct Liner Application Standard
ACGIH Threshold Limit Values
3. Terminology
3.1 Definitions:
3.1.1 threshold limit value (TLV)—the concentration in parts of vapor per million parts of air, by volume at 25°C and 101.3 kPa
(1 atm) pressure. This value is an indication of the relative inhalation toxicity hazard of vapors from volatile solvents used in
adhesives. Data on TLV of materials are published annually by ACGIH.
3.1.2 For definitions of other terms on thermal insulating materials used in this specification, see Terminology C168.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 flammable vehicle—in an adhesive, the liquid portion having a flash point as determined by Test Methods D93.
This specification is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.33 on Insulation Finishes
and Moisture.
Current edition approved Sept. 1, 2014March 1, 2020. Published September 2014March 2020. Originally approved in 1979. Last previous edition approved in 20072014
as C916 – 85C916 – 14.(2007). DOI: 10.1520/C0916-14.10.1520/C0916-20.
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.
Available from National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02169-7471, http://www.nfpa.org.
Sheet Metal and Air Conditioning Contractors National Assn., 4201 Lafayette Center Drive, Chantilly, VA 20151–1219, http://www.smacna.org.
Available from American Conference of Governmental Industrial Hygienists, Inc. (ACGIH), 1330 Kemper Meadow Dr., Suite 600, Cincinnati, OH 45240,
http://www.acgih.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C916 − 20
3.2.2 nonflammable vehicle— in an adhesive, the liquid portion having no flash point as determined by Test Methods D93.
4. Classification of Adhesives
4.1 Adhesives supplied under this specification are classified as follows:
4.1.1 Type I—An adhesive in which the vehicle is nonflammable in the liquid (wet) state and which will pass the edge-burning
test of 6.2.
4.1.2 Type II—An adhesive in which the vehicle is nonflammable in the liquid (wet) state and which will not pass the
edge-burning test of 6.2.
4.1.3 Type III—An adhesive in which the vehicle is flammable in the liquid (wet) state and which will pass the edge-burning
test of 6.2.
4.1.4 Type IV—An adhesive in which the vehicle is flammable in the liquid (wet) state and which will not pass the edge-burning
test of 6.2.
5. Ordering Information
5.1 Attention of the purchaser is directed to the fact that four types of adhesives are available under this specification. If the
purchaser does not specify which type is desired, the supplier shall furnish Type I only. Other purchaser options are described in
6.1.4 and 6.1.5.
6. Physical Requirements
6.1 Requirements Applicable to All Types:
6.1.1 Bonding Strength—The adhesive shall have a bonding strength of not less than 0.5 lb/in. (9.0 g/mm) of width after testing
under each condition of room temperature, high humidity, and heating, as specified in 7.2, 7.3, and 7.4.
6.1.2 Bond Retention After Heat-Aging—Duct liner fiber shall remain bonded to at least 75 % of the total area of each specimen
after testing as specified in 7.5.
6.1.3 Flame Spread and Smoke Developed—Adhesive for duct liner shall have a fire hazard classification not to exceed 25 for
flame spread and 50 for smoke developed. Classification shall be determined by Test Method E84. A report from a qualified testing
laboratory to indicate that fire hazard classification does not exceed that specified is acceptable. Tests shall be conducted as stated
in 7.6.
6.1.4 Storage Stability—The adhesive shall meet the requirements specified herein after completion of storage for a period of
6 months under the conditions specified in 7.8. If acceptable to the purchaser, and instead of performing a storage stability test on
each shipment, the manufacturer shall provide evidence that previous commercial lots of the adhesive have met satisfactorily the
6 months storage stability requirement.
6.1.5 Other Physical Requirements—Other requirements may be mutually agreed upon between the purchaser and the seller.
These requirements may include viscosity, bonding time, solids content, color, and odor.
6.2 Edge Burning Test for Types I and III Adhesives—In addition to the general requirements stated above, Types I and III
adhesives shall meet the following requirement: When tested by the method described in 7.7, there shall be no residual flame or
continuous burning of any specimen for more than 3 s after the test flame is extinguished.
7. Test Methods
7.1 Significance and Use—The tests described herein are intended to evaluate the suitability of the adhesive for service in
bonding fibrous glass thermal insulation duct liner by exposing specimens to simulated service conditions. The edge-burning test
(7.7) is useful for distinguishing between adhesive types to identify flame-retardance after curing of the adhesive.
7.2 Bonding Strength at Room Temperature:
7.2.1 Prepare the specimens in accordance with Test Method D903. The specimens shall be composed of 18-gage (0.05-in.,
1.3-mm) galvanized steel bonded to 8-oz (0.3-kg/m ) cotton canvas. The galvanized steel shall have been cleaned with solvent and
dried.
7.2.2 Apply the adhesive by brushing or spraying in accordance with the manufacturer’s recommendation for thickness. Apply
the adhesive to the metal surface only. As soon as the applied adhesive has become tacky as determined by finger pressure, bond
the canvas to the metal. Immediately after bonding, roll the canvas with a hand roller weighing 5 lb per lineal inch of roller (90
kg/m) (that is, a roller 4 in. long should have a total weight of 20 lb), to ensure uniform contact between adherends. Condition
the specimens for 24 h at a relative humidity of 50 6 2 % at 73.4 6 2°F (23 6 1°C). Test the specimens as described in Test
Method D903 except that the rate of travel of the power-actuated grip of the testing machine shall be 2 in. (50 mm)/min.
7.3 Bonding Strength at High Humidity—Prepare the specimens as described in 7.2 except that after the 24-h conditioning
period specified, further condition the specimens by exposure to a relative humidity of 95 % minimum at 73.4 6 2°F (23 6 1°C)
for 24 h. Conduct the
...