ASTM C1320-20

Standard Practice for Installation of Mineral Fiber Batt and Blanket Thermal Insulation for Light Frame Construction

SIGNIFICANCE AND USE
4.1 This practice recognizes that effectiveness, safety, and durability of insulation depend not only on the quality of the insulating materials but also on their proper installation.  
4.2 This practice provides general procedures that will help to ensure installation of insulation in a safe and effective manner. It shall be noted that actual conditions in existing buildings vary greatly and in some cases additional care shall be taken to ensure effective and safe installation.
SCOPE
1.1 This practice covers procedures for the installation of mineral fiber batt and blanket thermal insulation in ceilings, attics, floors, and walls of new or existing housing and other light frame construction.  
1.2 This practice covers the installation process from pre-installation inspection through post-installation inspection. It does not cover the production of the insulation materials.  
1.3 This practice is not intended to replace installation instructions by manufacturers, but it shall be used in conjunction with such instructions. This practice is not intended to supersede local, state, or federal codes.  
1.4 This practice assumes that the installer possesses a working knowledge of applicable codes and regulations, safety practices, tools, equipment, and methods necessary for the installation of thermal insulation materials. It also assumes that the installer understands the fundamentals of construction that affect the installation of insulation.  
1.5 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.  
1.6 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 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: 91.100.60 - Thermal and sound insulating materials
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.23 - Blanket and Loose Fill Insulation

Relations

• Replaces: ASTM C1320-10(2016) - Standard Practice for Installation of Mineral Fiber Batt and Blanket Thermal Insulation for Light Frame Construction
• 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 C755-20 - Standard Practice for Selection of Water Vapor Retarders for Thermal Insulation
• Effective Date: 01-Mar-2020
• Refers: ASTM C755-19b - Standard Practice for Selection of Water Vapor Retarders for Thermal Insulation
• Effective Date: 15-Oct-2019
• Refers: ASTM C755-19a - Standard Practice for Selection of Water Vapor Retarders for Thermal Insulation
• Effective Date: 01-Sep-2019
• Refers: ASTM D3833/D3833M-96(2019) - Standard Test Method for Water Vapor Transmission of Pressure-Sensitive Tapes
• Effective Date: 01-Aug-2019
• Refers: ASTM E84-19b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM C755-19 - Standard Practice for Selection of Water Vapor Retarders for Thermal Insulation
• Effective Date: 15-Apr-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

Overview

ASTM C1320-20 outlines the standard practice for the installation of mineral fiber batt and blanket thermal insulation in ceilings, attics, floors, and walls of light frame construction for both new and existing buildings. Developed by ASTM International, this guideline is essential for ensuring that insulation is installed safely, effectively, and in full compliance with building codes and industry best practices. The standard recognizes that correct installation is just as critical as the quality of the insulation material in achieving optimal thermal performance, safety, and longevity.

Key Topics

• Scope of Application: Covers installation procedures for mineral fiber batt and blanket insulation in residential and light commercial buildings, addressing ceilings, attics, walls, and floor assemblies.
• Pre-Installation Requirements: Includes inspection of the installation area for structural issues, moisture damage, and proper ventilation provisions prior to installing insulation.
• Installation Procedures: Addresses handling, fitting, and placement of insulation materials, ensuring there are no gaps, compression, or blockages of ventilation. Emphasizes fitting insulation snugly around obstructions and maintaining required thickness for rated R-values.
• Vapor Retarder Placement: Provides guidance on vapor retarder facing installation, the orientation of vapor retarders, and local code requirements for face or inset stapling.
• Safety Practices: Details the importance of protective clothing, electrical safety, minimum clearances around heat-producing devices, and compliance with fire codes.
• Post-Installation Inspection: Ensures the insulation is properly installed with no voids or compression, venting is maintained, and proper documentation (such as attic cards or receipts indicating coverage and R-value) is provided for building owners.

Applications

ASTM C1320-20 serves a wide range of practical applications in the construction industry focused on energy efficiency and safety:

• New Construction: Provides a standardized approach for contractors and builders to install mineral fiber batts and blankets in new housing or light commercial structures, ensuring energy-efficient and code-compliant thermal protection.
• Retrofit Projects: Offers a clear methodology for upgrading thermal performance in existing buildings, especially where attics, crawlspaces, and walls require additional insulation.
• Building Inspections: Acts as a reference for building inspectors and energy auditors to verify that insulation is properly installed according to industry best practices.
• Specifier Reference: Used by architects, designers, and engineers specifying mineral fiber batt and blanket insulation to ensure their designed assemblies meet performance requirements.
• Contractor Training: Provides training guidance for insulation installers to follow a consistent, safe, and effective installation process.

Related Standards

ASTM C1320-20 references several other key standards and codes critical for mineral fiber insulation installation:

• ASTM C168: Terminology related to thermal insulation.
• ASTM C665: Specification for mineral-fiber blanket thermal insulation for light frame construction and manufactured housing.
• ASTM C755: Practice for selection of water vapor retarders for thermal insulation.
• ASTM D3833/D3833M: Test method for water vapor transmission of pressure-sensitive tapes.
• ASTM E84: Test method for surface burning characteristics of building materials.
• NFPA 31, 54, 70, 211: National Fire Protection Association codes for the installation of heating equipment, fuel gas, electrical installations, and chimneys.
• ICC International Residential Code: Provisions for ventilation and construction requirements.
• CPSC Product Safety Fact Sheet No. 518: Guidance on residential electrical system safety.

Practical Value

Utilizing ASTM C1320-20 ensures proper installation of mineral fiber insulation, promoting energy efficiency, occupant safety, and building durability. Adhering to this standard helps minimize thermal bridging, avoid installation defects, and maintain compliance with local, state, and federal codes. The document serves as an authoritative reference for achieving reliable, high-quality thermal insulation performance in light frame construction projects.

Keywords: ASTM C1320, mineral fiber insulation, batt insulation, blanket insulation, light frame construction, thermal insulation installation, energy efficiency, building codes, insulation 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: C1320 − 20
Standard Practice for
Installation of Mineral Fiber Batt and Blanket Thermal
Insulation for Light Frame Construction
This standard is issued under the fixed designation C1320; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers procedures for the installation of
C168Terminology Relating to Thermal Insulation
mineral fiber batt and blanket thermal insulation in ceilings,
C665Specification for Mineral-Fiber BlanketThermal Insu-
attics, floors, and walls of new or existing housing and other
lation for Light Frame Construction and Manufactured
light frame construction.
Housing
1.2 This practice covers the installation process from pre-
C755Practice for Selection of Water Vapor Retarders for
installation inspection through post-installation inspection. It
Thermal Insulation
does not cover the production of the insulation materials.
D3833/D3833MTest Method for Water Vapor Transmission
1.3 This practice is not intended to replace installation of Pressure-Sensitive Tapes
instructions by manufacturers, but it shall be used in conjunc-
E84Test Method for Surface Burning Characteristics of
tion with such instructions. This practice is not intended to Building Materials
supersede local, state, or federal codes.
2.2 Other Standards:
NFPA-31 Standard for the Installation of Oil Burning
1.4 This practice assumes that the installer possesses a
Equipment
workingknowledgeofapplicablecodesandregulations,safety
NFPA-54National Fuel Gas Code
practices, tools, equipment, and methods necessary for the
NFPA-70National Electric Code
installationofthermalinsulationmaterials.Italsoassumesthat
NFPA-211Standard for Chimneys, Fireplaces,Vents and
the installer understands the fundamentals of construction that
Solid-Fuel Burning Appliances
affect the installation of insulation.
ICC International Residential Code
1.5 The values stated in inch-pound units are to be regarded
CPSC Product Safety Fact Sheet No. 518“The Home
as standard. The values given in parentheses are mathematical 5
Electrical System”
conversions to SI units that are provided for information only
and are not considered standard.
3. Terminology
1.6 This standard does not purport to address all of the
3.1 Definitions—Definitions relating to thermal insulation
safety concerns, if any, associated with its use. It is the
in Terminology C168 apply to terms used in this practice.
responsibility of the user of this standard to establish appro-
3.2 Description of Terms Specific to This Standard:
priate safety, health, and environmental practices and deter-
3.2.1 conditioned space—space in a building that is served
mine the applicability of regulatory limitations prior to use.
by a heating or cooling system.
1.7 This international standard was developed in accor-
3.2.2 installer—the person or persons who apply thermal
dance with internationally recognized principles on standard-
insulation materials in buildings whether or not such person or
ization established in the Decision on Principles for the
persons have contracted with the owner to perform the work.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
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.
1 3
This practice is under the jurisdiction of ASTM Committee C16 on Thermal Available from National Fire Protection Association (NFPA), 1 Batterymarch
Insulation and is the direct responsibility of Subcommittee C16.23 on Blanket and Park, Quincy, MA 02169-7471, http://www.nfpa.org.
Loose Fill Insulation. Available from International Code Council (ICC), 500 New Jersey Ave., NW,
Current edition approved March 1, 2020. Published March 2020. Originally 6th Floor, Washington, DC 20001-2070, http://www.iccsafe.org.
approved in 1995. Last previous edition approved in 2016 as C1320–10 (2016). AvailablefromU.S.ConsumerProductSafetyCommission(CPSC),4330East
DOI: 10.1520/C1320-20. West Hwy., Bethesda, MD 20814, http://www.cpsc.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1320 − 20
3.2.3 mineral fiber batt and blanket thermal insulating 6.6 Inspect attic floors for openings that might permit
materials—those materials that meet the minimum require- entrance of air from conditioned spaces below. Do not install
ments set forth in Specification C665. insulation in such areas until the owner has been informed and
has certified that these conditions have been corrected.
3.2.4 owner—the person, partnership, corporation, agency,
or other entity who owns the building to be insulated whether
7. Installation Procedures
such ownership is by virtue of deed, contract, or any other
instrument for acquiring legal title under the laws of the State
7.1 General:
in which the building is located.
7.1.1 Handle the insulation material in accordance with the
3.2.5 vapor retarder—membrane or tape that has a water manufacturer’s instructions and keep free of extraneous mate-
−11
rials. Keep materials dry, off the ground, and protected from
vapor permeance (perm) rating of 1 perm (5.7×10
−1
−1 −2
kg·Pa ·s ·m ) or less as defined in Practice C755 or Test water.
Method D3833/D3833M respectively. 7.1.2 It is difficult to describe every situation that will be
encounteredbytheinsulationinstaller.Ingeneral,however,the
4. Significance and Use
installershallbeguidedbytheneedtoreduceheatflowaround
4.1 This practice recognizes that effectiveness, safety, and
or through obstructions and to protect mechanical systems.
durability of insulation depend not only on the quality of the
Wherever insulation is installed in a building, it is very
insulating materials but also on their proper installation.
important that it fit snugly on all sides. If the insulation is too
long for a space, cut it to the correct size. If it is too short, cut
4.2 This practice provides general procedures that will help
a piece to fill the void.
to ensure installation of insulation in a safe and effective
7.1.3 Install the insulation in such a way that the thickness
manner. It shall be noted that actual conditions in existing
specified by the manufacturer is met or exceeded. Avoid
buildings vary greatly and in some cases additional care shall
compression of the insulation where ever possible. Failure to
be taken to ensure effective and safe installation.
achieve the manufacturer’s labeled thickness will reduce the
5. Safety Precautions
R-value.
5.1 The installer shall wear proper clothing and equipment 7.1.4 When a vapor retarder facing is provided with the
as recommended by the insulation manufacturer.
insulation,itcanbepressurefitwithnostaplingorfacestapled
or inset stapled. Both inset and face staple methods are widely
5.2 In areas where insulation is to be installed, components
used and are acceptable procedures. Inset stapling is usually
of the electrical system shall be in good condition. If there is
preferred by the wall finish trades because it allows adhesive
reason to believe the electrical system is faulty, do not install
applicationofthewallboard.Someareasrequirefacestapling.
insulation in such areas until the owner has been informed and
Always check the local code requirements.
repair has been accomplished.
7.1.4.1 Position the vapor retarder toward the winter-warm
NOTE 1—The CPSC Product Safety Fact Sheet No. 518 has identified
side, except in a hot, humid climate where local requirements
the following signs of electrical deficiencies: lights dimming, fuses
or practices differ regarding the placement of vapor retarders.
blowing, circuit breakers tripping frequently, electrical sparks and “glow-
7.1.4.2 FrictionfitbattssuchasR13,R15,R21,R22,R30C,
ing” from receptacles, light flickering, and coverplates on switches and
outlets that are warm or hot to the touch. or R38C as well as kraft faced batts without attached stapling
flanges do not have to be stapled in place. The higher density
6. Pre-installation Inspection and Preparation
or increased glass batt width of these products helps hold them
6.1 Inspect the roof, walls, ceilings, and attic floors to
inplacewithoutameasurablelossinthemoistureprotectionof
identify areas where previous or existing moisture problems
thevaporretarder.Makesuretheinsulationfacingisflushwith
have caused paint peeling, warpage, staining, visible fungus
the face of the stud. The insulation shall fit snugly at the sides
growth, rotting, or other structural damage. Do not install
and ends while completely filling the cavity for sidewall
insulation in such areas until the owner has been informed and
applications with the insulation contacting all six sides of the
hascertifiedthattheseconditionshavebeencorrectedandtheir
cavity.
sour
...

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: C1320 − 10 (Reapproved 2016) C1320 − 20
Standard Practice for
Installation of Mineral Fiber Batt and Blanket Thermal
Insulation for Light Frame Construction
This standard is issued under the fixed designation C1320; 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 covers procedures for the installation of mineral fiber batt and blanket thermal insulation in ceilings, attics,
floors, and walls of new or existing housing and other light frame construction.
1.2 This practice covers the installation process from pre-installation inspection through post-installation inspection. It does not
cover the production of the insulation materials.
1.3 This practice is not intended to replace installation instructions by manufacturers, but it shall be used in conjunction with
such instructions. This practice is not intended to supersede local, state, or federal codes.
1.4 This practice assumes that the installer possesses a working knowledge of applicable codes and regulations, safety practices,
tools, equipment, and methods necessary for the installation of thermal insulation materials. It also assumes that the installer
understands the fundamentals of construction that affect the installation of insulation.
1.5 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.
1.6 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:
C168 Terminology Relating to Thermal Insulation
C665 Specification for Mineral-Fiber Blanket Thermal Insulation for Light Frame Construction and Manufactured Housing
C755 Practice for Selection of Water Vapor Retarders for Thermal Insulation
D3833/D3833M Test Method for Water Vapor Transmission of Pressure-Sensitive Tapes
E84 Test Method for Surface Burning Characteristics of Building Materials
2.2 Other Standards:
NFPA-31 Standard for the Installation of Oil Burning Equipment
NFPA-54 National Fuel Gas Code
NFPA-70 National Electric Code
NFPA-211 Standard for Chimneys, Fireplaces,Vents and Solid-Fuel Burning Appliances
ICC International Residential Code
CPSC Product Safety Fact Sheet No. 518 “The Home Electrical System”
This practice is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.23 on Blanket and Loose
Fill Insulation.
Current edition approved March 1, 2016March 1, 2020. Published March 2016March 2020. Originally approved in 1995. Last previous edition approved in 20102016 as
C1320 – 10.C1320 – 10 (2016). DOI: 10.1520/C1320-10R16.10.1520/C1320-20.
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.
Available from International Code Council (ICC), 500 New Jersey Ave., NW, 6th Floor, Washington, DC 20001-2070, http://www.iccsafe.org.
Available from U.S. Consumer Product Safety Commission (CPSC), 4330 East West Hwy., Bethesda, MD 20814, http://www.cpsc.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1320 − 20
3. Terminology
3.1 Definitions—Definitions relating to thermal insulation in Terminology C168 apply to terms used in this practice.
3.2 Description of Terms Specific to This Standard:
3.2.1 conditioned space—space in a building that is served by a heating or cooling system.
3.2.2 installer—the person or persons who apply thermal insulation materials in buildings whether or not such person or persons
have contracted with the owner to perform the work.
3.2.3 mineral fiber batt and blanket thermal insulating materials—those materials that meet the minimum requirements set forth
in Specification C665.
3.2.4 owner—the person, partnership, corporation, agency, or other entity who owns the building to be insulated whether such
ownership is by virtue of deed, contract, or any other instrument for acquiring legal title under the laws of the State in which the
building is located.
−11 −1 −1
3.2.5 vapor retarder—membrane or tape that has a water vapor permeance (perm) rating of 1 perm (5.7 × 10 kg·Pa ·s ·m
−2) or less as defined in Practice C755 or Test Method D3833/D3833M respectively.
4. Significance and Use
4.1 This practice recognizes that effectiveness, safety, and durability of insulation depend not only on the quality of the
insulating materials but also on their proper installation.
4.2 This practice provides general procedures that will help to ensure installation of insulation in a safe and effective manner.
It shall be noted that actual conditions in existing buildings vary greatly and in some cases additional care shall be taken to ensure
effective and safe installation.
5. Safety Precautions
5.1 The installer shall wear proper clothing and equipment as recommended by the insulation manufacturer.
5.2 In areas where insulation is to be installed, components of the electrical system shall be in good condition. If there is reason
to believe the electrical system is faulty, do not install insulation in such areas until the owner has been informed and repair has
been accomplished.
NOTE 1—The CPSC Product Safety Fact Sheet No. 518 has identified the following signs of electrical deficiencies: lights dimming, fuses blowing,
circuit breakers tripping frequently, electrical sparks and “glowing” from receptacles, light flickering, and coverplates on switches and outlets that are
warm or hot to the touch.
6. Pre-installation Inspection and Preparation
6.1 Inspect the roof, walls, ceilings, and attic floors to identify areas where previous or existing moisture problems have caused
paint peeling, warpage, staining, visible fungus growth, rotting, or other structural damage. Do not install insulation in such areas
until the owner has been informed and has certified that these conditions have been corrected and their source(s) of moisture
eliminated.
6.2 Provide proper attic ventilation in accordance with local building requirements or practices, such as the ICC International
Residential Code.
6.3 When the attic has soffit vents at the eaves, make provisions to prevent insulation from blocking the vents and restricting
attic ventilation.
6.4 Where insulation is to be installed beneath floors over crawl spaces or on crawl space walls, cover the ground surface with
a vapor retarder.
6.5 Provide proper crawl space ventilation in accordance with local building requirements or practices, such as the ICC
International Residential Code.
6.6 Inspect attic floors for openings that might permit entrance of air from conditioned spaces below. Do not install insulation
in such areas until the owner has been informed and has certified that these conditions have been corrected.
7. Installation Procedures
7.1 General:
7.1.1 Handle the insulation material in accordance with the manufacturer’s instructions and keep free of extraneous materials.
Keep materials dry, off the ground, and protected from water.
7.1.2 It is difficult to describe every situation that will be encountered by the insulation installer. In general, however, the
installer shall be guided by the need to reduce heat flow around or through obstructions and to protect mechanical systems.
Wherever insulation is installed in a building, it is very important that it fit snugly on all sides. If the insulation is too long for a
space, cut it to the correct size. If it is too short, cut a piece to fill the void.
C1320 − 20
7.1.3 Install the insulation in such a way that the thickness specified by the manufacturer is met or exceeded. Avoid compression
of the insulation where ever possible. Failure to achieve the manufacturer’s labeled thickness will reduce the R-value.
7.1.4 When a vapor retarder facing is provided with the insulation, it can be pressure fit with no stapling or face stapled or inset
stapled. Both inset and face staple methods are widely used and are acceptable procedures. Inset stapling is usually preferred by
the wall finish trades because it allows adhesive application of the wall board. Some areas require face stapling. Always check the
local code requir
...