ASTM D7954/D7954M-22a
(Practice)Standard Practice for Moisture Surveying of Roofing and Waterproofing Systems Using Nondestructive Electrical Impedance Scanners
Standard Practice for Moisture Surveying of Roofing and Waterproofing Systems Using Nondestructive Electrical Impedance Scanners
SIGNIFICANCE AND USE
5.1 Excess moisture trapped in roofing or waterproofing systems can adversely affect performance and lead to premature failure of roofing or waterproofing systems and its components. It also reduces thermal resistance, resulting in reduced energy efficiency and inflated energy costs. Impedance scans can be effective in identifying concealed and entrapped moisture within roofing or waterproofing systems.
5.2 This practice is intended to be used at various stages of the roofing and waterproofing system’s life such as: during or at completion of installation of roofing or waterproofing system to determine if there was moisture intrusion into the roofing or waterproofing system or underlying materials; at regular intervals as part of a preventative maintenance program; and to aid in condition assessment, or before replacement or repair work, or combinations thereof, to assist in determining the extent of work and replacement materials.
5.3 This practice alone does not determine the cause of moisture infiltration into roofing or waterproofing systems; however, it can be used to help tracing excess moisture to the point of ingress.
SCOPE
1.1 This practice applies to techniques that use nondestructive electrical impedance (EI) scanners to locate moisture and evaluate the comparative moisture content within insulated low-slope roofing and waterproofing systems.
1.2 This practice is applicable to roofing and waterproofing systems wherein insulation is placed above the deck and positioned underneath and in contact with electrically nonconductive single-ply or built-up roofing and waterproofing membranes and systems such as coal tar, asphalt, modified bitumen, thermoplastics, spray polyurethane foam, and similar electrically nonconductive membrane materials. This practice is also applicable to roofing and waterproofing systems without insulation placed above moisture absorbing decks such as wood, concrete, or gypsum, that are in contact with single-ply or built-up roofing and waterproofing membranes as described above.
1.3 This practice is applicable to roofing and waterproofing systems incorporating electrically nonconductive rigid board insulation made from materials such as organic fibers, perlite, cork, fiberglass, wood-fiber, polyisocyanurate, polystyrene, phenolic foam, composite boards, gypsum substrate boards, and other electrically nonconductive roofing and waterproofing systems such as spray-applied polyurethane foam.
1.4 This practice is not appropriate for all combinations of materials used in roofing and waterproofing systems.
1.4.1 Metal and other electrically conductive surface coverings and near-surface embedded metallic components are not suitable for surveying with impedance scanners because of the electrical conductivity of these materials.
1.4.2 This practice is not appropriate for use with black EPDM, any membranes containing black EPDM, or black EPDM coatings because black EPDM gives false positive readings.
1.4.3 Aluminum foil on top-faced insulation, roofing, or waterproofing membranes gives a false positive reading and is not suitable for surveying with impedance scanners; however, liquid-applied aluminum pigmented emulsified asphalt-based coatings shall not normally affect impedance scanner readings.
1.4.3.1 This practice is not appropriate for use with aluminium foil faced modified bitumen membranes, as the electrical conductivity of the aluminium foil surface can give false positive readings.
1.4.4 While their overburden remains in place, this practice is not appropriate for use with inverted roof membrane assemblies (IRMAs) or protected roof assemblies (PRMAs), which contain above the deck waterproof membrane and overburden that may include insulation, drainage components, pavers, aggregate, ballast, vegetation, or combinations thereof, because the impedance scanner will not differentiate between above and below the membrane moisture.
1.4.5 S...
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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:D7954/D7954M −22a
Standard Practice for
Moisture Surveying of Roofing and Waterproofing Systems
1
Using Nondestructive Electrical Impedance Scanners
This standard is issued under the fixed designation D7954/D7954M; 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 1.4.3 Aluminum foil on top-faced insulation, roofing, or
waterproofing membranes gives a false positive reading and is
1.1 This practice applies to techniques that use nondestruc-
not suitable for surveying with impedance scanners; however,
tive electrical impedance (EI) scanners to locate moisture and
liquid-applied aluminum pigmented emulsified asphalt-based
evaluate the comparative moisture content within insulated
coatings shall not normally affect impedance scanner readings.
low-slope roofing and waterproofing systems.
1.4.3.1 This practice is not appropriate for use with alu-
1.2 This practice is applicable to roofing and waterproofing
minium foil faced modified bitumen membranes, as the elec-
systems wherein insulation is placed above the deck and
trical conductivity of the aluminium foil surface can give false
positioned underneath and in contact with electrically noncon-
positive readings.
ductive single-ply or built-up roofing and waterproofing mem-
1.4.4 While their overburden remains in place, this practice
branes and systems such as coal tar, asphalt, modified bitumen,
is not appropriate for use with inverted roof membrane
thermoplastics, spray polyurethane foam, and similar electri-
assemblies (IRMAs) or protected roof assemblies (PRMAs),
cally nonconductive membrane materials. This practice is also
which contain above the deck waterproof membrane and
applicable to roofing and waterproofing systems without insu-
overburden that may include insulation, drainage components,
lation placed above moisture absorbing decks such as wood,
pavers, aggregate, ballast, vegetation, or combinations thereof,
concrete, or gypsum, that are in contact with single-ply or
because the impedance scanner will not differentiate between
built-up roofing and waterproofing membranes as described
above and below the membrane moisture.
above.
1.4.5 SeeA1.4forsomecautionarynotesonroofinganoma-
1.3 This practice is applicable to roofing and waterproofing
lies and limitations that affect the impedance test practice.
systems incorporating electrically nonconductive rigid board
1.5 Moisture scanners using impedance-based technology
insulation made from materials such as organic fibers, perlite,
are classified as EI scanners.
cork, fiberglass, wood-fiber, polyisocyanurate, polystyrene,
phenolic foam, composite boards, gypsum substrate boards,
NOTE 1—The term capacitance is sometimes used when describing
andotherelectricallynonconductiveroofingandwaterproofing
impedance scanners. Capacitance scanners are purely capacitive as they
systems such as spray-applied polyurethane foam. do not have a resistive component. Impedance scanners combine both
capacitance and resistance for testing; thus, they are well suited to the
1.4 This practice is not appropriate for all combinations of
measurement of different types of materials and constructions found in
materials used in roofing and waterproofing systems. roofingandwaterproofingsystemsasthecombinationofbothcomponents
allows for a more versatile testing, calibration, and measurement arrange-
1.4.1 Metal and other electrically conductive surface cover-
ment.
ings and near-surface embedded metallic components are not
suitable for surveying with impedance scanners because of the 1.6 This practice also addresses necessary verification of
electrical conductivity of these materials.
impedance data involving invasive test procedures using core
1.4.2 This practice is not appropriate for use with black samples.
EPDM, any membranes containing black EPDM, or black
1.7 This practice addresses two generally accepted scanning
EPDM coatings because black EPDM gives false positive
techniques for conducting moisture surveys using electrical
readings.
impedance scanners:
1.7.1 Technique A—Continuous systematic scanning and
recording (see 8.2), and
1
ThispracticeisunderthejurisdictionofASTMCommitteeD08onRoofingand
1.7.2 Technique B—Grid format scanning and recording
Waterproofing and is the direct responsibility of Subcommittee D08.20 on Roofing
(see 8.3).
Membrane Systems.
Current edition approved May 1, 2022. Published May 2022. Originally
1.8 This practice addresses some meteorological condition
...
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: D7954/D7954M − 22 D7954/D7954M − 22a
Standard Practice for
Moisture Surveying of Roofing and Waterproofing Systems
1
Using Nondestructive Electrical Impedance Scanners
This standard is issued under the fixed designation D7954/D7954M; 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 applies to techniques that use nondestructive electrical impedance (EI) scanners to locate moisture and evaluate
the comparative moisture content within insulated low-slope roofing and waterproofing systems.
1.2 This practice is applicable to roofing and waterproofing systems wherein insulation is placed above the deck and positioned
underneath and in contact with electrically nonconductive single-ply or built-up roofing and waterproofing membranes and systems
such as coal tar, asphalt, modified bitumen, thermoplastics, spray polyurethane foam, and similar electrically nonconductive
membrane materials. This practice is also applicable to roofing and waterproofing systems without insulation placed above
moisture absorbing decks such as wood, concrete, or gypsum, that are in contact with single-ply or built-up roofing and
waterproofing membranes as described above.
1.3 This practice is applicable to roofing and waterproofing systems incorporating electrically nonconductive rigid board
insulation made from materials such as organic fibers, perlite, cork, fiberglass, wood-fiber, polyisocyanurate, polystyrene, phenolic
foam, composite boards, gypsum substrate boards, and other electrically nonconductive roofing and waterproofing systems such
as spray-applied polyurethane foam.
1.4 This practice is not appropriate for all combinations of materials used in roofing and waterproofing systems.
1.4.1 Metal and other electrically conductive surface coverings and near-surface embedded metallic components are not suitable
for surveying with impedance scanners because of the electrical conductivity of these materials.
1.4.2 This practice is not appropriate for use with black EPDM, any membranes containing black EPDM, or black EPDM coatings
because black EPDM gives false positive readings.
1.4.3 Aluminum foil on top-faced insulation, roofing, or waterproofing membranes gives a false positive reading and is not
suitable for surveying with impedance scanners; however, liquid-applied aluminum pigmented emulsified asphalt-based coatings
shall not normally affect impedance scanner readings.
1.4.3.1 This practice is not appropriate for use with aluminium foil faced modified bitumen membranes, as the electrical
conductivity of the aluminium foil surface can give false positive readings.
1.4.4 While their overburden remains in place, this practice is not appropriate for use with inverted roof membrane assemblies
1
This practice is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.20 on Roofing
Membrane Systems.
Current edition approved April 15, 2022May 1, 2022. Published May 2022. Originally approved in 2014. Last previous edition approved in 20212022 as
D7954/D7954M – 15a (2021).D7954/D7954M – 22. DOI: 10.1520/D7954_D7954M-22.10.1520/D7954_D7954M-22A.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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D7954/D7954M − 22a
(IRMAs) or protected roof assemblies (PRMAs), which contain above the deck waterproof membrane and overburden that may
include insulation, drainage components, pavers, aggregate, ballast, vegetation, or combinations thereof, because the impedance
scanner will not differentiate between above and below the membrane moisture.
1.4.5 See A1.4 for some cautionary notes on roofing anomalies and limitations that affect the impedance test practice.
1.5 Moisture scanners using impedance-based technology are classified as EI scanners.
NOTE 1—The term capacitance is sometimes used when describing impedance scanners. Capacitance scanners are purely capacitive as they do not have
a resistive component. Impedance scanners combine both capacitance and resistance for testing; thus, they are well suited to the measurement of different
types of materials and constructions found in roofing and waterproofing systems as the combination of both components allows for a mor
...
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