ASTM C1060-23

Standard Practice for Thermographic Inspection of Insulation Installations in Envelope Cavities of Frame Buildings

SIGNIFICANCE AND USE
5.1 Although infrared imaging systems have the potential to determine many factors concerning the thermal performance of a wall, roof, floor, or ceiling, the emphasis in this practice is on determining whether insulation is missing or whether an insulation installation is malfunctioning. Anomalous thermal images from other apparent causes are not required to be recorded; however, if recorded as supplemental information, their interpretation is capable of requiring procedures and techniques not presented in this practice.
SCOPE
1.1 This practice is a guide to the proper use of infrared imaging systems for conducting qualitative thermal inspections of building walls, ceilings, roofs, and floors, framed in wood or metal, that contain insulation in the spaces between framing members. This procedure allows the detection of cavities where insulation is inadequate or missing and allows identification of areas with apparently adequate insulation.  
1.2 This practice offers reliable means for detecting suspected missing insulation. It also offers the possibility of detecting partial-thickness insulation, improperly installed insulation, or insulation damaged in service. Proof of missing insulation or a malfunctioning envelope requires independent validation. Validation techniques, such as visual inspection or in-situ R-value measurement, are beyond the scope of this practice.  
1.3 This practice is limited to frame construction even though thermography is used on all building types. (ISO 6781)  
1.4 Instrumentation and calibration required under a variety of environmental conditions are described. Instrumentation requirements and measurement procedures are considered for inspections from both inside and outside the structure. Each vantage point offers visual access to areas hidden from the other side.  
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. Specific precautionary statements are given in Note 1 and Note 3.  
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: 28-Feb-2023
• ICS: 91.080.20 - Timber structures
• ICS: 91.080.99 - Other structures
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.30 - Thermal Measurement

Relations

• Refers: ASTM C168-24 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2024
• 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 C168-15a - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Oct-2015
• Refers: ASTM C168-15 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jun-2015
• Refers: ASTM E1213-14 - Standard Practice for Minimum Resolvable Temperature Difference for Thermal Imaging Systems
• Effective Date: 01-Oct-2014
• Refers: ASTM C168-13 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Apr-2013
• Refers: ASTM C168-10 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jan-2010
• Refers: ASTM E1213-97(2009) - Standard Test Method for Minimum Resolvable Temperature Difference for Thermal Imaging Systems
• Effective Date: 01-Mar-2009
• Refers: ASTM C168-08b - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Dec-2008
• Refers: ASTM C168-08a - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Sep-2008
• Refers: ASTM C168-08 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jun-2008
• Refers: ASTM C168-05a - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Nov-2005
• Refers: ASTM C168-05 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 01-Jun-2005
• Refers: ASTM C168-03 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 10-Apr-2003

Overview

ASTM C1060-23 is the Standard Practice for Thermographic Inspection of Insulation Installations in Envelope Cavities of Frame Buildings. Developed by ASTM International, this standard offers guidelines for using infrared imaging systems to qualitatively inspect thermal insulation in framed walls, ceilings, roofs, and floors. The focus is to detect areas where insulation may be missing, defective, or installed improperly, supporting efforts to improve energy efficiency and building envelope performance in wood or metal frame constructions.

Thermographic inspection is a non-invasive method that visually maps temperature variations on building surfaces, helping building professionals assess insulation coverage without causing damage. This practice addresses essential steps, appropriate environmental conditions, instrumentation requirements, and data interpretation for achieving reliable inspection results.

Key Topics

• Qualitative Thermal Inspections: The standard explains procedures for qualitative thermographic surveys in frame buildings, focusing on cavities between framing members.
• Infrared Imaging Systems: Guidance is given on the choice, use, and calibration of infrared imaging equipment, including spatial and temperature resolution requirements.
• Detection Capabilities:
  • Identification of missing insulation
  • Detection of partial-thickness or damaged insulation
  • Recognition of anomalies signifying insulation defects or possible air leakage
• Inspection Conditions: Suitable temperature differentials, weather conditions, and avoidance of factors such as direct sunlight and wind that can affect accuracy.
• Reporting Requirements: Specifies what to include in the final inspection report, such as building details, equipment used, observed anomalies, and areas not inspected.

Applications

The use of ASTM C1060-23 is particularly valuable for:

• Building Diagnostics: Identifying thermal deficiencies in frame constructions to improve energy performance and occupant comfort.
• Quality Assurance in Construction: Verifying proper insulation installation during new construction or after retrofits.
• Maintenance and Renovation: Supporting facility managers and contractors in pinpointing insulation failures or degraded performance due to aging or damage.
• Energy Audits: Assisting energy auditors in detecting heat loss areas and formulating effective remediation plans.
• Regulatory Compliance: Meeting local building codes and energy efficiency standards that require verification of continuous thermal barriers.

Thermographic inspection, when performed under the conditions and protocols stated in this standard, enables reliable identification of insulation issues in wood or metal frame buildings without destructively accessing the envelope cavities.

Related Standards

For a comprehensive approach to thermographic inspection and insulation performance, consider these associated standards:

• ASTM C168: Terminology Relating to Thermal Insulation
• ASTM E1213: Practice for Minimum Resolvable Temperature Difference for Thermal Imaging Systems
• ISO 6781: Thermal Insulation – Qualitative Detection of Thermal Irregularities in Building Envelopes – Infrared Method

Practical Value

ASTM C1060-23 empowers building professionals to leverage infrared thermography to ensure insulation is continuous and effective, reducing energy costs and improving sustainability. It helps standardize the inspection process, increasing confidence in detection of hidden insulation failures. By following this practice, facility owners and inspectors can target repairs, validate new installations, and support compliance with energy performance requirements.

Keywords: ASTM C1060-23, thermographic inspection, insulation installation, building envelope, frame buildings, infrared imaging, thermal insulation, qualitative thermal inspection, energy efficiency, building diagnostics.

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: C1060 − 23
Standard Practice for
Thermographic Inspection of Insulation Installations in
Envelope Cavities of Frame Buildings
This standard is issued under the fixed designation C1060; 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 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice is a guide to the proper use of infrared
ization established in the Decision on Principles for the
imaging systems for conducting qualitative thermal inspections
Development of International Standards, Guides and Recom-
of building walls, ceilings, roofs, and floors, framed in wood or
mendations issued by the World Trade Organization Technical
metal, that contain insulation in the spaces between framing
Barriers to Trade (TBT) Committee.
members. This procedure allows the detection of cavities
where insulation is inadequate or missing and allows identifi-
2. Referenced Documents
cation of areas with apparently adequate insulation.
2.1 ASTM Standards:
1.2 This practice offers reliable means for detecting sus-
C168 Terminology Relating to Thermal Insulation
pected missing insulation. It also offers the possibility of
E1213 Practice for Minimum Resolvable Temperature Dif-
detecting partial-thickness insulation, improperly installed
ference for Thermal Imaging Systems
insulation, or insulation damaged in service. Proof of missing
2.2 ISO Standards:
insulation or a malfunctioning envelope requires independent
ISO 6781 :1983 Thermal Insulation—Qualitative detection
validation. Validation techniques, such as visual inspection or
of Thermal Irregularities in Building Envelopes—Infrared
in-situ R-value measurement, are beyond the scope of this
Method
practice.
1.3 This practice is limited to frame construction even 3. Terminology
though thermography is used on all building types. (ISO 6781)
3.1 Definitions—Definitions pertaining to insulation are de-
1.4 Instrumentation and calibration required under a variety fined in Terminology C168.
of environmental conditions are described. Instrumentation
3.2 Definitions of Terms Specific to This Standard:
requirements and measurement procedures are considered for
3.2.1 anomalous thermal image—an observed thermal pat-
inspections from both inside and outside the structure. Each
tern of a structure that is not in accordance with the expected
vantage point offers visual access to areas hidden from the
thermal pattern.
other side.
3.2.2 envelope—the construction, taken as a whole or in
1.5 The values stated in inch-pound units are to be regarded part, that separates the indoors of a building from the outdoors.
as standard. The values given in parentheses are mathematical
3.2.3 field-of-view (FOV)—the total angular dimensions,
conversions to SI units that are provided for information only
expressed in degrees or radians, within which objects can be
and are not considered standard.
imaged, displayed, and recorded by a stationary imaging
1.6 This standard does not purport to address all of the device.
safety concerns, if any, associated with its use. It is the
3.2.4 framing spacing—distance between the centerlines of
responsibility of the user of this standard to establish appro-
joists, studs, or rafters.
priate safety, health, and environmental practices and deter-
3.2.5 infrared imaging system—an instrument that converts
mine the applicability of regulatory limitations prior to use.
the spatial variations in infrared radiance from a surface into a
Specific precautionary statements are given in Note 1 and Note
3.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This practice is under the jurisdiction of ASTM Committee C16 on Thermal contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal Standards volume information, refer to the standard’s Document Summary page on
Measurement. the ASTM website.
Current edition approved March 1, 2023. Published March 2023. Originally Available from International Organization for Standardization, ISO Secretariat,
approved in 1986. Last previous edition approved in 2015 as C1060 – 11a (2015). BIBC II, Cheminde Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
DOI: 10.1520/C1060-23. http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1060 − 23
two-dimensional image of that surface, in which variations in cal test for these qualities is whether the operator is able to
radiance are displayed as a range of colors or tones. distinguish the framing from the envelope cavities under the
prevailing thermal conditions with the infrared imaging system
3.2.6 infrared thermography—the process of generating
at a distance that permits recognition of thermal anomalies. For
thermal images that represent temperature and emittance varia-
planning an equipment purchase or a site visit, the following
tions over the surfaces of objects.
qualities shall be considered: The minimum resolvable tem-
3.2.7 masonry veneer—frame construction with a non-load
perature difference (MRTD) defines temperature resolution.
bearing exterior masonry surface.
Instantaneous field of view (IFOV) is an indicator of spatial
3.2.8 measurement spatial resolution (IFOV )—The
meas resolution. Appendix X1 explains how to calculate IFOV and
smallest target spot size on which an infrared imager will
how to measure MRTD.
produce a measurement, expresses in terms of angular sub-
6.2.1 Spectral Range—The infrared thermal imaging system
tense.
shall operate within a spectral range between 2 and 14 μm.
6.2.2 Field of View (FOV)—The critical minimum dimen-
3.2.9 spatial resolution—the spot size in terms of working
distance. sions for discriminating missing insulation in frame construc-
tion is two framing spacings wide and one framing spacing
3.2.10 thermal pattern—a representation of colors or tones
high. Outdoors, it is typically convenient to view at least one
that indicate surface temperature and emittance variation.
floor-to-ceiling height across and one-half that distance high.
3.2.11 thermogram—a recorded image that maps the appar-
The FOV of the chosen imaging system should encompass
ent temperature pattern of an object or scene into a correspond-
these minimum dimensions from the chosen indoor viewing
ing contrast or color pattern.
distance, d , and outdoor viewing distance, d . For planning
i o
3.2.12 zone—a volume of building served by a single
purposes, the angular value of FOV shall be calculated for
ventilation system. For buildings with natural ventilation only,
either d (m) by the following equations:
the whole building shall be considered a zone with all interior
FOV $ 2 tan h/2d (1)
~ !
vertical
doors open.
FOV $ 2 tan w/2d (2)
~ !
horizontal
4. Summary of Practice
where:
4.1 This practice is a guide to the proper use of infrared
h = vertical distance viewed, m, and
imaging systems for conducting qualitative thermal inspections
w = horizontal distance viewed, m.
of building walls, ceilings, roofs, and floors, framed in wood or
metal, that contain insulation in the spaces between framing
7. Knowledge Requirement
members. Imaging system performance is defined in terms of
7.1 This practice requires operation of the imaging system
spatial and measurement resolution as well as thermal sensi-
and interpretation of the data obtained. When qualified, the
tivity. Conditions under which information is to be collected
same person has the option of performing both functions. The
and compiled in a report are specified. Adherence to this
operator of the infrared imaging system shall have thorough
standard practice requires a final report of the investigation.
knowledge of its use through training, the manufacturer’s
This practice defines the contents of the report.
manuals, or both. The interpreter of the thermographic data
shall be knowledgeable about heat transfer through building
5. Significance and Use
envelopes and about thermography, including the effects of
5.1 Although infrared imaging systems have the potential to
stored heat, wind, surface moisture, and the surrounding
determine many factors concerning the thermal performance of
conditions.
a wall, roof, floor, or ceiling, the emphasis in this practice is on
7.2 The instrument shall be operated in accordance with the
determining whether insulation is missing or whether an
published instructions of the manufacturer.
insulation installation is malfunctioning. Anomalous thermal
images from other apparent causes are not required to be
8. Preferred Conditions
recorded; however, if recorded as supplemental information,
8.1 The criterion for satisfactory thermal conditions is the
their interpretation is capable of requiring procedures and
ability to distinguish framing members from cavities. Appen-
techniques not presented in this practice.
dix X2 gives some guidelines for determining whether the
6. Instrumentation Requirements weather conditions are likely to be suitable.
6.1 Environmental Factors—The environment has a signifi-
9. Procedure
cant impact on the heat flow through the envelope. As a result,
the requirements on thermal imaging instrumentation vary with 9.1 Preliminary Inspection—A preliminary thermographic
the interior to exterior air temperature gradient for both interior inspection may be performed to determine whether a thorough
and exterior inspections and also vary with wind speed for inspection, and report, is warranted.
exterior inspections.
9.2 Background Information—Prepare for the report by
6.2 Infrared Imaging System Performance—The ability of collecting information on the building. In order to evaluate the
an observer to detect thermal anomalies depends on the structure, collect the following preliminary data where practi-
imager’s powers of thermal and spatial resolution. The practi- cal and necessary:
C1060 − 23
9.2.1 Note each type of building cross section, using visual 10.1.1 Locations of the regions where insulation is appar-
inspection, construction drawings, or both, to determine what ently missing or defective and their total area.
thermal patterns to expect. 10.1.2 Locations of the regions where the insulation is
9.2.2 Additions or modifications to the structure. apparently intact and their total area.
9.2.3 Thermal problems reported by the building owner/
10.1.3 Location and total area of added insulation (if 10.1.1
occupant. and 10.1.2 were performed in a thermographic inspection prior
9.2.4 Note differences in surface materials or conditions that
to adding insulation).
will affect emittance, for example, metallic finishes, polished 10.1.4 Estimated total area of surfaces that cannot be
surfaces, stains, or moisture. Such differences in emittance
inspected.
cause thermal patterns that are independent of temperature
10.2 Interpretation of thermographic images requires aware-
differences.
ness of the following types of patterns:
9.2.5 Orientation of the building with respect to the points
10.2.1 Intact Insulation—As seen from the warm side of the
of the compass.
construction: dark parallel lines, representing the framing;
9.2.6 Heat sources, such as light fixtures, mounted in or
uniformly lighter areas between the framing lines, representing
close to the exterior or interior of the envelope.
the insulation. As seen from the cool side of the construction:
9.3 Performing On-Site Equipment Check and Settings:
the framing lines are light. The areas containing insulation are
9.3.1 Set the instrument gain or contrast to allow the
uniformly dark.
observer to distinguish a framing member from the envelope
NOTE 1—Metal framing with no insulation may fit this description. See
area around it. In addition, set the imager’s thermal level or
Note 2.
brightness so that any anomalies or areas to which they are
NOTE 2—Metal framing conducts heat better than both air and insula-
referenced are not in saturation (maximum brightness or white)
tion. If insulation is present, the thermal contrast between metal framing
and the spaces between may be very strong. Independent verification may
or in suppression (minimum brightness or black) on the
be needed for metal-framed buildings to establish typical patterns for
display.
insulated and uninsulated areas.
9.3.2 Verify proper operation of the recording system, if
10.2.2 Insulation Missing Completely—As seen from the
any.
warm side of the construction: light parallel lines, representing
9.3.3 Make a sketch or photograph of each envelope area
the framing; darker areas between the framing lines, represent-
with references for locating framing members.
ing the empty space between framing members. Convection
9.4 Performing the Inspection:
will be visible in vertical framing, as evidenced by a gradient
9.4.1 A complete thermographic inspection of a building
from dark (cooler) at the bottom of the space to light (warmer)
will consist of an exterior or interior inspection of the complete
at the top. As seen from the cool side of the construction: the
envelope, or both. Both types of inspection are recommended
framing lines are dark, the areas between framing are light and
because each offers access to areas that are difficult for the
convection is still lighter at the top of vertical spaces.
other.
NOTE 3—Metal framing with no insulation may not fit this description.
9.4.2 Inspect all surfaces of interest from an angle as close
See Note 2.
to normal to the surface as possible, but at least at an angle that
permits distinguishing framing members. Make inspections
10.2.3 Insulation Partially Missing—The dominant effect is
from several angles, perpendicular, if possible, and at two
as described in 10.2.1, except that missing insulation shows as
opposite oblique angles in order to detect the presence of
a well-defined dark region, as seen from the warm side and as
reflected radiation.
a light region as seen from the cool side.
9.4.3 Inspect from a position that allows a field of view that
10.2.4 Other Thermal Patterns—Irregular variation of the
encompasses at least two framing spacings wide and one
thermal pattern in the spaces between framing members
framing spacing high for an interior inspection and a floor-to-
indicate a combination of possible causes, including varying
ceiling height wide and one-half that distance high for an
density of insulation, convection or air leakage, moisture, or
exterior inspection.
thermal bridges. A partial list of examples follows:
9.4.4 Effective corrective action requires a precise definition
10.2.4.1 Variable density insulation often allows air leakage
of the areas with apparent defects. Record each anomaly with
and convection and thereby creates intruding areas of surface
annotation regarding the location of all recognizable building
temperature variation.
characteristics such as windows, doors, and v
...

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: C1060 − 11a (Reapproved 2015) C1060 − 23
Standard Practice for
Thermographic Inspection of Insulation Installations in
Envelope Cavities of Frame Buildings
This standard is issued under the fixed designation C1060; 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 is a guide to the proper use of infrared imaging systems for conducting qualitative thermal inspections of building
walls, ceilings, roofs, and floors, framed in wood or metal, that contain insulation in the spaces between framing members. This
procedure allows the detection of cavities where insulation is inadequate or missing and allows identification of areas with
apparently adequate insulation.
1.2 This practice offers reliable means for detecting suspected missing insulation. It also offers the possibility of detecting
partial-thickness insulation, improperly installed insulation, or insulation damaged in service. Proof of missing insulation or a
malfunctioning envelope requires independent validation. Validation techniques, such as visual inspection or in-situR-value
measurement, are beyond the scope of this practice.
1.3 This practice is limited to frame construction even though thermography is used on all building types. (ISO 6781)
1.4 Instrumentation and calibration required under a variety of environmental conditions are described. Instrumentation
requirements and measurement procedures are considered for inspections from both inside and outside the structure. Each vantage
point offers visual access to areas hidden from the other side.
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 and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Note 1 and Note 3.
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
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 Sept. 1, 2015March 1, 2023. Published October 2015March 2023. Originally approved in 1986. Last previous edition approved in 20112015 as
C1060 – 11a.C1060 – 11a (2015). DOI: 10.1520/C1060-11AR15.10.1520/C1060-23.
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
C1060 − 23
E1213 Practice for Minimum Resolvable Temperature Difference for Thermal Imaging Systems
2.2 ISO Standards:
ISO 6781 :1983 Thermal Insulation—Qualitative detection of Thermal Irregularities in Building Envelopes—Infrared Method
3. Terminology
3.1 Definitions—Definitions pertaining to insulation are defined in Terminology C168.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 anomalous thermal image—an observed thermal pattern of a structure that is not in accordance with the expected thermal
pattern.
3.2.2 envelope—the construction, taken as a whole or in part, that separates the indoors of a building from the outdoors.
3.2.3 field-of-view (FOV)—the total angular dimensions, expressed in degrees or radians, within which objects can be imaged,
displayed, and recorded by a stationary imaging device.
3.2.4 framing spacing—distance between the centerlines of joists, studs, or rafters.
3.2.5 infrared imaging system—an instrument that converts the spatial variations in infrared radiance from a surface into a
two-dimensional image of that surface, in which variations in radiance are displayed as a range of colors or tones.
3.2.6 infrared thermography—the process of generating thermal images that represent temperature and emittance variations over
the surfaces of objects.
3.2.7 masonry veneer—frame construction with a non-load bearing exterior masonry surface.
3.2.8 measurement spatial resolution (IFOV )—The smallest target spot size on which an infrared imager will produce a
meas
measurement, expresses in terms of angular subtense.
3.2.9 spatial resolution—the spot size in terms of working distance.
3.2.10 thermal pattern—a representation of colors or tones that indicate surface temperature and emittance variation.
3.2.11 thermogram—a recorded image that maps the apparent temperature pattern of an object or scene into a corresponding
contrast or color pattern.
3.2.12 zone—a volume of building served by a single ventilation system. For buildings with natural ventilation only, the whole
building shall be considered a zone with all interior doors open.
4. Summary of Practice
4.1 This practice is a guide to the proper use of infrared imaging systems for conducting qualitative thermal inspections of building
walls, ceilings, roofs, and floors, framed in wood or metal, that contain insulation in the spaces between framing members. Imaging
system performance is defined in terms of spatial and measurement resolution as well as thermal sensitivity. Conditions under
which information is to be collected and compiled in a report are specified. Adherence to this standard practice requires a final
report of the investigation. This practice defines the contents of the report.
5. Significance and Use
5.1 Although infrared imaging systems have the potential to determine many factors concerning the thermal performance of a
wall, roof, floor, or ceiling, the emphasis in this practice is on determining whether insulation is missing or whether an insulation
Available from International Organization for Standardization, ISO Secretariat, BIBC II, Cheminde Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
http://www.iso.org.
C1060 − 23
installation is malfunctioning. Anomalous thermal images from other apparent causes are not required to be recorded; however,
if recorded as supplemental information, their interpretation is capable of requiring procedures and techniques not presented in this
practice.
6. Instrumentation Requirements
6.1 Environmental Factors—The environment has a significant impact on the heat flow through the envelope. As a result, the
requirements on thermal imaging instrumentation vary with the interior to exterior air temperature gradient for both interior and
exterior inspections and also vary with wind speed for exterior inspections.
6.2 Infrared Imaging System Performance—The ability of an observer to detect thermal anomalies depends on the imager’s
powers of thermal and spatial resolution. The practical test for these qualities is whether the operator is able to distinguish the
framing from the envelope cavities under the prevailing thermal conditions with the infrared imaging system at a distance that
permits recognition of thermal anomalies. For planning an equipment purchase or a site visit, the following qualities shall be
considered: The minimum resolvable temperature difference (MRTD) defines temperature resolution. Instantaneous field of view
(IFOV) is an indicator of spatial resolution. Appendix X1 explains how to calculate IFOV and how to measure MRTD.
6.2.1 Spectral Range—The infrared thermal imaging system shall operate within a spectral range between 2 and 14 μm.
6.2.2 Field of View (FOV)—The critical minimum dimensions for discriminating missing insulation in frame construction is two
framing spacings wide and one framing spacing high. Outdoors, it is typically convenient to view at least one floor-to-ceiling height
across and one-half that distance high. The FOV of the chosen imaging system should encompass these minimum dimensions from
the chosen indoor viewing distance, d , and outdoor viewing distance, d . For planning purposes, the angular value of FOV shall
i o
be calculated for either d (m) by the following equations:
FOV $ 2 tan h/2d (1)
~ !
vertical
FOV $ 2 tan ~w/2d! (2)
horizontal
where:
h = vertical distance viewed, m, and
w = horizontal distance viewed, m.
7. Knowledge Requirement
7.1 This practice requires operation of the imaging system and interpretation of the data obtained. When qualified, the same person
has the option of performing both functions. The operator of the infrared imaging system shall have thorough knowledge of its
use through training, the manufacturer’s manuals, or both. The interpreter of the thermographic data shall be knowledgeable about
heat transfer through building envelopes and about thermography, including the effects of stored heat, wind, and surface
moisture.surface moisture, and the surrounding conditions.
7.2 The instrument shall be operated in accordance with the published instructions of the manufacturer.
8. Preferred Conditions
8.1 The criterion for satisfactory thermal conditions is the ability to distinguish framing members from cavities. Appendix X2
gives some guidelines for determining whether the weather conditions are likely to be suitable.
9. Procedure
9.1 Preliminary Inspection—A preliminary thermographic inspection may be performed to determine whether a thorough
inspection, and report, is warranted.
9.2 Background Information—Prepare for the report by collecting information on the building. In order to evaluate the structure,
collect the following preliminary data where practical and necessary:
9.2.1 Note each type of building cross section, using visual inspection, construction drawings, or both, to determine what thermal
patterns to expect.
C1060 − 23
9.2.2 Additions or modifications to the structure.
9.2.3 Thermal problems reported by the building owner/occupant.
9.2.4 Note differences in surface materials or conditions that will affect emittance, for example, metallic finishes, polished
surfaces, stains, or moisture. Such differences in emittance cause thermal patterns that are independent of temperature differences.
9.2.5 Orientation of the building with respect to the points of the compass.
9.2.6 Heat sources, such as light fixtures, mounted in or close to the exterior or interior of the envelope.
9.3 Performing On-Site Equipment Check and Settings:
9.3.1 Set the instrument gain or contrast to allow the observer to distinguish a framing member from the envelope area around
it. In addition, set the imager’s thermal level or brightness so that any anomalies or areas to which they are referenced are not in
saturation (maximum brightness or white) or in suppression (minimum brightness or black) on the display.
9.3.2 Verify proper operation of the recording system, if any.
9.3.3 Make a sketch or photograph of each envelope area with references for locating framing members.
9.4 Performing the Inspection:
9.4.1 A complete thermographic inspection of a building will consist of an exterior or interior inspection of the complete envelope,
or both. Both types of inspection are recommended because each offers access to areas that are difficult for the other.
9.4.2 Inspect all surfaces of interest from an angle as close to normal to the surface as possible, but at least at an angle that permits
distinguishing framing members. Make inspections from several angles, perpendicular, if possible, and at two opposite oblique
angles in order to detect the presence of reflected radiation.
9.4.3 Inspect from a position that allows a field of view that encompasses at least two framing spacings wide and one framing
spacing high for an interior inspection and a floor-to-ceiling height wide and one-half that distance high for an exterior inspection.
9.4.4 Effective corrective action requires a precise definition of the areas with apparent defects. Record each anomaly with
annotation regarding the location of all recognizable building characteristics such as windows, doors, and vents. The record may
accommodate any requirement for calculations of envelope areas with anomalies.
10. Thermographic Interpretation
10.1 If apparent defects in insulation are not confirmed, corrected, and reinspected at the time of the thermographic survey, then
thermograms or other precise identification of the locations and types of apparent defects are required. The interpretation of the
thermogram allows determination of the following information:
10.1.1 Locations of the regions where insulation is apparently missing or defective and their total area.
10.1.2 Locations of the regions where the insulation is apparently intact and their total area.
10.1.3 Location and total area of added insulation (if 10.1.1 and 10.1.2 were performed in a thermographic inspection prior to
adding insulation).
10.1.4 Estimated total area of surfaces that cannot be inspected.
10.2 Interpretation of thermographic images requires awareness of the following types of patterns:
10.2.1 Intact Insulation—As seen from the warm side of the construction: dark parallel lines, representing the framing; uniformly
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lighter areas between the framing lines, representing the insulation. As seen from the cool side of the construction: the framing
lines are light. The areas containing insulation are uniformly dark.
NOTE 1—Metal framing with no insulation may fit this description. See Note 2.
NOTE 2—Metal framing conducts heat better than both air and insulation. If insulation is present, the thermal contrast between metal framing and the
spaces between may be very strong. Independent verification may be needed for metal-framed buildings to establish typical patterns for insulated and
uninsulated areas.
10.2.2 Insulation Missing Completely—As seen from the warm side of the construction: light parallel lines, representing the
framing; darker areas between the framing lines, representing the empty space between framing members. Convection will be
visible in vertical framing, as evidenced by a gradient from dark (cooler) at the bottom of the space to light (warmer) at the top.
As seen from the cool side of the construction: the framing lines are dark, the areas between framing are light and convection is
still lighter at the top of vertical spaces.
NOTE 3—Metal framing with no insulation may not fit this description. See Note 2.
10.2.3 Insulation Partially Missing—The dominant effect
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