ASTM D1079-20

Standard Terminology Relating to Roofing and Waterproofing

General Information

• Status: Published
• Publication Date: 30-Apr-2020
• ICS: 01.040.91 - Construction materials and building (Vocabularies)
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: D08 - Roofing and Waterproofing
• Drafting Committee: D08.01 - Nomenclature, Definitions and Editorial

Relations

• Replaces: ASTM D1079-18e1 - Standard Terminology Relating to Roofing and Waterproofing
• Effective Date: 01-May-2020
• Refers: ASTM C1289-23a - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 01-Sep-2023
• Refers: ASTM C591-19a - Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
• Effective Date: 01-Nov-2019
• Refers: ASTM C591-19 - Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
• Effective Date: 01-Mar-2019
• Refers: ASTM C1289-18a - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 15-Nov-2018
• Refers: ASTM C1289-18 - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 01-Sep-2018
• Refers: ASTM D450/D450M-07(2018) - Standard Specification for Coal-Tar Pitch Used in Roofing, Dampproofing, and Waterproofing
• Effective Date: 01-May-2018
• Refers: ASTM C591-17 - Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
• Effective Date: 01-Sep-2017
• Refers: ASTM C1289-17 - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 01-Jul-2017
• Refers: ASTM C1289-16a - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 01-Dec-2016
• Refers: ASTM D312/D312M-16 - Standard Specification for Asphalt Used in Roofing
• Effective Date: 01-May-2016
• Refers: ASTM C591-16 - Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate<brk/>Thermal Insulation
• Effective Date: 15-Apr-2016
• Refers: ASTM C33/C33M-16e1 - Standard Specification for Concrete Aggregates
• Effective Date: 01-Feb-2016
• Refers: ASTM C1289-16 - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 15-Jan-2016
• Refers: ASTM C1289-15 - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
• Effective Date: 01-May-2015

Overview

ASTM D1079-20: Standard Terminology Relating to Roofing and Waterproofing serves as a foundational reference for terminology used in the roofing and waterproofing industries. Published by ASTM International, this standard provides clear, consensus-based definitions for terms commonly applied in the specification, design, installation, and inspection of roofing and waterproofing systems. The document is maintained by ASTM Committee D08, which specializes in roofing and waterproofing standards.

With a focus on precise language, ASTM D1079-20 ensures that professionals-such as architects, contractors, manufacturers, and inspectors-share a common understanding of industry terms. This unified vocabulary supports effective communication and reduces the risk of misinterpretation in documents, construction practices, and product specifications.

Key Topics

ASTM D1079-20 covers a diverse range of terminology, including but not limited to:

• Roofing System Components: Definitions for layers such as membranes, base sheets, cap sheets, and insulation boards (e.g., "membrane," "base ply," "cap flashing").
• Material Types: Descriptions of bituminous and non-bituminous materials, including asphalt, coal tar, polyisocyanurate, and mineral aggregates.
• Application Methods: Terms for installation practices, such as mopping, brooming, and backnailing.
• Performance and Testing: Definitions related to weathering, permeability, penetrations, and compaction testing.
• Defects and Issues: Language describing failures and phenomena like blisters, alligatoring, ridging, and fishmouth.

Many definitions reference other ASTM standards, highlighting the interconnected nature of material and installation specifications in roofing and waterproofing.

Applications

ASTM D1079-20 finds broad application in several industry practices:

• Specification Writing: Standardized terminology ensures that project specifications and procurement documents are interpreted consistently.
• Product Development: Manufacturers use the definitions to accurately describe products and ensure compliance with relevant standards.
• Training and Education: Industry professionals and trainees reference this standard to familiarize themselves with accepted industry language.
• Inspection and Compliance: Inspectors and quality assurance professionals rely on standard definitions when communicating findings or deficiencies.

By promoting a shared language, ASTM D1079-20 underpins technical clarity and regulatory compliance across all project phases, from initial design through construction, maintenance, and renovation.

Related Standards

ASTM D1079-20 functions as a reference point for many other ASTM standards relevant to roofing and waterproofing materials and practices. Notable related standards include:

• ASTM C33/C33M: Specification for Concrete Aggregates
• ASTM C591 / C1289: Specifications for Polyisocyanurate Insulation
• ASTM D312 / D450: Specifications for Asphalt and Coal-Tar Pitch used in roofing
• ASTM D4586: Specification for Asphalt Roof Cement, Asbestos-Free
• ASTM D698 / D1557: Test Methods for Soil Compaction in construction applications
• ASTM D6136: Test Method for Kerosine Number of Unsaturated Felt

By integrating terminology from ASTM D1079-20 into these standards and industry documents, professionals can achieve greater clarity, efficiency, and safety in roofing and waterproofing projects.

Keywords: ASTM D1079-20, roofing terminology, waterproofing standards, roofing materials, bituminous roofing, ASTM standards, construction terminology, building envelope, roofing inspection, roofing system components, building specification.

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: D1079 −20
Standard Terminology Relating to
Roofing and Waterproofing
This standard is issued under the fixed designation D1079; 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. Referenced Documents anionic emulsion, n—an emulsion in which the emulsifying
2 system establishes a predominance of negative charges on
1.1 ASTM Standards:
the discontinuous phase.
C33/C33MSpecification for Concrete Aggregates
C591Specification for Unfaced Preformed Rigid Cellular
application rate, n—the quantity (mass, volume or thickness)
Polyisocyanurate Thermal Insulation
of material applied per unit area.
C1289Specification for Faced Rigid Cellular Polyisocyanu-
artificial weathering, v—exposure to conditions, which may
rate Thermal Insulation Board
be cyclic, involving temperature, relative humidity, radiant
D312/D312MSpecification for Asphalt Used in Roofing
energy,and/oranyotherconditionsorpollutantsfoundinthe
D450/D450M Specification for Coal-Tar Pitch Used in
atmosphere in various geographical areas, which may accel-
Roofing, Dampproofing, and Waterproofing
erate changes in properties of materials over those of natural
D698Test Methods for Laboratory Compaction Character-
weather conditions.
istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600
kN-m/m ))
asbestos, n—a group of natural fibrous impure silicate mate-
D1557Test Methods for Laboratory Compaction Character-
rials.
istics of Soil Using Modified Effort (56,000 ft-lbf/ft
(2,700 kN-m/m )) asphalt, n—a dark brown to black cementitious material in
which the predominating constituents are bitumens that
D6136/D6136MTest Method for Kerosine Number of Un-
occur in nature or are obtained in petroleum processing.
saturated (Dry) Felt by Vacuum Method
asphalt, air blown, n—an asphalt produced by blowing air
2. Terminology
throughmoltenasphaltatanelevatedtemperaturetoraiseits
2.1 Definitions:
softening point and modify other properties.
accelerated weathering, v—the exposure of a specimen to a
asphaltene, n—a high molecular weight hydrocarbon fraction
specifiedtestenvironmentforaspecifiedtimewiththeintent
precipitated from asphalt by a designated paraffinic naphtha
of producing, in a shorter time period, effects similar to
solvent at a specified temperature and solvent-asphalt ratio.
actual weathering.
DISCUSSION—The asphaltene fraction should be identified by the
aggregate, n—(1) crushed stone, crushed slag, or water-worn temperature and solvent-asphalt ratio used.
gravel used for surfacing a built-up roof; (2) any granular
asphalt felt, n—an asphalt-saturated felt.
mineral material.
asphaltite, n—a natural asphalt found below ground level.
alligatoring, v—the cracking of the surfacing bitumen on a
built-up roof, producing a pattern of cracks similar to an
asphalt mastic, n—a mixture of asphaltic material and graded
alligator’s hide; the cracks may not extend through the
mineral aggregate that can be poured when heated, but
surfacing bitumen.
requires mechanical manipulation to apply.
asphalt rock (rock asphalt), n—a naturally occurring rock
formation, usually limestone or sandstone, containing
This terminology is under the jurisdiction of ASTM Committee D08 on
throughout its mass a minor amount of asphalt.
RoofingandWaterproofingandisthedirectresponsibilityofSubcommitteeD08.01
on Nomenclature, Definitions and Editorial.
asphalt roof cement, n—a trowelable mixture of asphalt,
Current edition approved May 1, 2020. Published June 2020. Originally
solvents, mineral stabilizers, fillers or fibers, or both.
approved in 1950. Last previous edition approved in 2018 as D1079–18. DOI:
10.1520/D1079-20.
2 asphalt roof cement, n—see flashing cement.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
asphalt, steam blown, n—an asphalt produced by blowing
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. steam through molten asphalt to modify its properties.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1079 − 20
backnailing, v—the practice of blind-nailing roofing felts to a built-up roofing, n—a continuous, semiflexible membrane
substrate in addition to hot-mopping to prevent slippage. consisting of plies of saturated felts, coated felts, fabrics or
mats assembled in place with alternate layers of bitumen,
bald roof—See smooth-surfaced roof.
and surfaced with mineral aggregate, bituminous materials,
base ply, n—the bottom or first ply in a built-up roofing
or a granule surfaced sheet (abbreviation, BUR).
membrane when additional plies are to be subsequently
installed.
cant strip, n—a beveled strip used under flashings to modify
the angle at the point where the roofing or waterproofing
base sheet, n—a product intended to be used as a base ply in
membrane meets any vertical element.
a built-up roofing system.
cap flashing—See flashing.
bitumen, n—(1) a class of amorphous, black or dark-colored,
cap sheet, n—agranule-surfacedcoatedfeltusedasthetopply
(solid,semi-solid,orviscous)cementitioussubstances,natu-
of a built-up roofing membrane.
ralormanufactured,composedprincipallyofhighmolecular
weight hydrocarbons, soluble in carbon disulfide, and found
cationic emulsion, n—an emulsion in which the emulsifying
in asphalts, tars, pitches, and asphaltites; (2) a generic term
systemestablishesapredominanceofpositivechargesonthe
used to denote any material composed principally of bitu-
discontinuous phase.
men.
caulking, n—a composition of vehicle and pigment, used at
bitumen trap—See pitch pocket.
ambient temperatures for filling joints, that remains plastic
bituminized, adj—impregnated with bitumen. Example: bitu-
for an extended time after application.
minized fiber pipe.
channel mopping—See mopping, (3) strip.
bituminous, adj—containing or treated with bitumen. Ex-
coal tar, n—a dark brown to black cementitious material
amples: bituminous concrete, bituminous felts and fabrics,
produced by the destructive distillation of coal.
bituminous pavement.
bituminous emulsion, n—(1) a suspension of minute globules coal tar roof cement, n—a trowelable mixture of processed
of bituminous material in water or in an aqueous solution; coal tar base, solvents, mineral fillers or fibers, or both.
(2) a suspension of minute globules of water or of an
coal-tar felt, n—afeltthathasbeensaturatedwithrefinedcoal
aqueous solution in a liquid bituminous material (invert
tar.
emulsion).
coal-tar pitch, n—a dark brown to black, solid cementitious
bituminous grout, n—a mixture of bituminous material and
material obtained as residue in the partial evaporation or
fine sand that will flow into place without mechanical
distillation of coal tar.
manipulation when heated.
coated sheet (or felt), n—(1) an asphalt felt that has been
blast-furnace slag, n—the nonmetallic product, consisting
coated on both sides with harder, more viscous asphalt; (2)
essentially of silicates and alumino-silicates of calcium and
a glass fiber felt that has been simultaneously impregnated
other bases, that is developed in a molten condition simul-
and coated with asphalt on both sides.
taneously with iron in a blast furnace.
blind nailing, v—the use of nails that are not exposed to the
coke-oven tar—See coal tar.
weather in the finished roofing.
cold-process roofing, n—a continuous, semiflexible mem-
brane consisting of plies of felts, mats, or fabrics laminated
blister, n—(1)araisedportionofaroofingmembraneresulting
on a roof with alternate layers of roof cement and surfaced
from local internal pressure; (2) the similarly formed protu-
with a cold-applied coating.
berances in coated prepared roofing.
concealed membrane waterproofing, n—also referred to as
blocking, n—(1) wood built into a roofing system above the
structural slab waterproofing; (1) for below grade: refers
deck and below the membrane and flashing to (a) stiffen the
toaformofwaterproofingwherethemembraneisappliedto
deck around an opening, (b) act as a stop for insulation, (c)
the mud mat and later covered with a topping, usually
serveasanailerforattachmentofthemembraneorflashing.
concrete, to act as a wearing layer or course, and (2) for
(2)woodcross-membersinstalledbetweenraftersorjoists
elevated structural concrete deck: applied over the structural
to provide support at cross-joints between deck panels.
surface and covered/concealed by other components such as
(3) cohesion or adhesion between similar or dissimilar
a topping slab, pavers, ballast, pavement, and plantings.
materials in roll or sheet form that may interfere with the
satisfactory and efficient use of the material.
condensation, n—theconversionofwatervapororothergasto
liquid as the temperature drops or atmospheric pressures
blueberry—See strawberry.
rises. (See also dew point).
bond, n—theadhesiveandcohesiveforcesholdingtworoofing
components in intimate contact.
conditioning, v—the storage of a specimen under specified
brooming, v—embedding a ply by using a broom to smooth it temperature, humidity, etc., for a specified time prior to
out and ensure contact with the adhesive under the ply. testing.
D1079 − 20
conductance, thermal, n—the thermal transmission in unit double pour, v—to apply two layers of aggregate and bitumen
time through unit area of a particular body or assembly to a built-up roof.
having defined surfaces, when unit average temperature
2 dry felt, n—(1) see felt; (2) a felt which has not been saturated
difference is established between the surfaces. C=W⁄m ·K
2 with bitumen.
(C=Btu⁄h·ft ·°F).
edge stripping, v—application of felt strips cut to narrower
conductivity, thermal, n—the thermal transmission, by con-
widths than the normal felt-roll width to cover a joint
duction only, in unit time through unit area between two
between flashing and built-up roofing.
isothermal surfaces of an infinite slab of a homogeneous
material of unit thickness, in a direction perpendicular to the
edge venting, v—the practice of providing regularly spaced
surface, when unit temperature difference is established
protectedopeningsataroofperimetertorelievewatervapor
between the surfaces. k=W⁄m·K (k=Btu·in.⁄h·ft ·°F).
pressure in the insulation.
cone penetration—See penetration.
elastomer, n—a macromolecular material that returns rapidly
coping, n—a covering on top of a wall exposed to the weather,
to its approximate initial dimensions and shape after sub-
usually sloped to carry off water.
stantialdeformationbyaweakstressandsubsequentrelease
of that stress.
counterflashing, n—formed metal or elastomeric sheeting
secured on or into a wall, curb, pipe, roof-top unit, or other
embedment, v—(1) the process of pressing a felt, aggregate,
surface, to cover and protect the upper edge of a base
fabric, mat, or panel uniformly and completely into hot
flashing and its associated fasteners.
bitumen or adhesive to ensure intimate contact at all points;
(2) the process of pressing granules into coating in the
coverage, n—the surface area to be continuously covered by a
manufacture of factory-prepared roofing, such as shingles.
specific quantity of a particular material.
emulsion, n—an intimate mixture of bitumen and water, with
creep, n—the time-dependent part of a strain resulting from
uniformdispersionofthebitumenorwaterglobules,usually
stress.
stabilized by an emulsifying agent or system.
cricket, n—aconstructiontodivertwateraroundorawayfrom
envelope, n—a continuous membrane edge seal formed at the
a chimney, curb, wall, expansion joint, or other penetration.
perimeterandatpenetrationsbyfoldingthebasesheetorply
(See saddle).
over the plies above and securing it to the top of the
membrane.Theenvelopepreventsbitumenseepagefromthe
crushed stone, n—the product resulting from the artificial
edge of the membrane.
crushing of rocks, boulders, or large cobblestones, substan-
tially all faces of which have resulted from the crushing
equilibrium moisture content, n—(1) the moisture content of
operation.
a material stabilized at a given temperature and relative
humidity, expressed as percent moisture by weight; (2) the
cutback, n—solvent-thinned bitumen used in cold-process
typical moisture content of a material in any given geo-
roofing adhesives, flashing cements, and roof coatings.
graphical area.
cutoff, n—a detail designed to prevent lateral water movement
equiviscous temperature (EVT), n—thetemperatureatwhich
intotheinsulationwherethemembraneterminatesattheend
abitumenattainstheproperviscosityforbuilt-upmembrane
of a day’s work, or used to isolate sections of the roofing
application. EVT may or may not be applicable to polymer
system. It is usually removed before the continuation of the
modified bituminous sheet materials. (See EVT for asphalt
work.
and EVT for coal tar).
dampproofing, v—treatment of a surface or structure to resist
DISCUSSION—In England, EVT is the temperature corresponding to a
the passage of water in the absence of hydrostatic pressure.
standard efflux time from a road tar viscometer.
dead level, adj—absolutely horizontal, or zero slope (see also equiviscous temperature for asphalt, n—the equiviscous
temperature (EVT) for roofing asphalt (Specification D312/
slope).
D312M, Type I, II, III, or IV) is as follows: (1) mop
dead level asphalt, n—a roofing asphalt conforming to the
application—the temperature at which the asphalt’s appar-
requirements of Specification D312/D312M, Type I.
ent viscosity is 125 cP. (2) mechanical spreader
application—the temperature at which the asphalt’s appar-
dead level roofing, n—a roofing system applied on a surface
ent viscosity is 75 cP. See equiviscous temperature and
witha0to2% incline.
EVT application range.
deck, n—the structural surface to which the roofing or water-
equiviscous temperature for coal tar, n—the equiviscous
proofing system (including insulation) is applied.
temperature (EVT) for roofing coal tar (Specification D450/
direction change, n—a change in the orientation of the D450M, Type I or III) is the temperature at which the coal
principal dimension or of the support of adjoining units of tar’s apparent viscosity is 25 cP. See equiviscous tempera-
the roofing system. ture and EVT application range.
D1079 − 20
EVT application range, n—the bitumen application tempera- covers the edges of the membrane. Cap or counterflashing
ture range. The range is from 25°F below the EVT to 25°F shields the upper edges of the base flashing.
abovetheEVT(50°Fspan).Thetemperatureismeasuredin
flashing cement, n—a trowelable mixture of cutback bitumen
the mop cart or mechanical spreader just prior to the
and mineral stabilizers including asbestos or other inorganic
application of bitumen to the substrate.
fibers.
expansion joint, n—astructuralseparationbetweentwobuild-
flat asphalt, n—a roofing asphalt conforming to the require-
ing elements that allows free movement between the ele-
ments of Specification D312/D312M, Type II.
ments without damage to the roofing or waterproofing
system.
flood coat, n—the top layer of bitumen used to hold the
aggregate on an aggregate-surfaced, built-up roofing mem-
exposure, n—(1)thetransversedimensionofaroofingelement
brane.
not overlapped by an adjacent element in any roofing
system. The exposure of any ply in a membrane may be
fluid-applied elastomer, n—an elastomeric material, fluid at
computedbydividingthefeltwidthminus51mm(2in.),by
ambient temperature, that dries or cures after application to
the number of shingled plies; thus, the exposure of a
formacontinuousmembrane.Suchsystemsnormallydonot
914-mm (36-in.) wide felt in a shingled, four-ply membrane
incorporate reinforcement.
should be 216 mm (8 ⁄2 in.); (2) the time during which a
flux, n—a bituminous material used as a feed stock for further
portion of a roofing element is exposed to the weather.
processing and as a material to soften other bituminous
extra-steep asphalt—See super-steep asphalt.
materials.
fabric, n—a woven or nonwoven cloth of organic or inorganic
“free carbon” in tars, n—the hydrocarbon fraction that is
filaments, threads, or yarns.
precipitated from a tar by dilution with carbon disulfide.
facer, n—the outermost, adhered top or bottom, or both, sheet
(or layer) of an insulation board that is comprised of a glass felt, n—glass fibers bonded into a sheet with resin and
different material than the insulation itself. It is commonly suitable for impregnation in the manufacture of bituminous
composed of organic paper, glass mat, or a combination waterproofing, roofing membranes, and shingles.
thereof, generally impregnated or coated, or both, with
glass mat, n—a thin mat of glass fibers with or without a
asphalt, latex, or the like; or metal foil.
binder.
2 2
factory square, n—10 m (108 ft ).
glaze coat, n—(1)thetoplayerofasphaltinasmooth-surfaced
fallback, n—areductioninbitumensofteningpoint,sometimes
built-up roof assembly; (2) a thin protective coating of
caused by refluxing or overheating in a relatively closed
bitumen applied to the lower plies or top ply of a built-up
container. (See also softening point drift).
membrane, when application of additional felts, or the flood
coat and aggregate surfacing are delayed.
felt, n—a flexible sheet manufactured by the interlocking of
fibers with a binder or through a combination of mechanical
granule—See mineral granules.
work, moisture, and heat. Felts are manufactured principally
gravel, n—coarse, granular aggregate, with pieces larger than
from vegetable fibers (organic felts), asbestos fibers (asbes-
sand grains, resulting from the natural erosion of rock.
tosfelts)orglassfibers(glassfiberfelts);otherfibersmaybe
gravel in, v—to spread aggregate into hot bitumen on the
present in each type.
surface of the roofing membrane.
felt layer, n—(1) a machine used for applying bitumen and
gravel stop, n—aflangeddevice,frequentlymetallic,designed
built-up roofing felts; (2) See ply.
to prevent loose aggregate from washing off the roof and to
felt mill ream, n—the mass in pounds of 480 ft of dry,
provide a continuous finished edge for the roofing.
unsaturated felt, also termed “point weight.”
headlap, n—in roofing, for products installed in a shingle
fine mineral surfacing, n—water-insolubleinorganicmaterial,
fashion, the area on a shingle or sheet material that is
more than 50% of which passes the 500-µm (No. 35) sieve,
covered by the requisite number of layers in multiply
used on the surface of roofing.
construction; for example, two layers on a strip shingle or
three layers in a three-ply built-up roof. Headlap is com-
finger blisters, n—finger shaped blisters or wrinkles in the
monlyreferredtobyitswidth,thusthedesignationbylinear
plies of a built-up roofing or waterproofing membrane.
dimension. For multiple sheet roofing, see Fig. 1. For
finger wrinkles—See finger blisters.
shingles, see Fig. 2.
fishmouth, n—(1) a half-cylindrical or half-conical opening
heat exposure, v—the process of subjecting a specimen to an
formedbyanedgewrinkleorfailuretoembedaroofingfelt;
elevated temperature at atmospheric pressure for a specified
(2) in shingles, a half-conical opening formed at a cut edge.
period of time with the intent of determining properties by
flashing, n—the system used to seal membrane edges at walls,
subsequent testing.
expansionjoints,drains,gravelstops,andotherplaceswhere
the membrane is interrupted or terminated. Base flashing holiday—an area where a liquid-applied material is missing.
D1079 − 20
FIG. 1 Headlap in Multiple Sheet Roofing
“hot stuff” or “hot”, n—a roofer’s term for hot bitumen. incline, n—the slope of a roof expressed in percent or in the
number of vertical units of rise per horizontal unit of run.
hydrokinetic roof system, n—a roof system that depends on
inorganic, adj—being or composed of matter other than
quick drainage via water shedding to prevent water entry
hydrocarbons and their derivatives, or matter that is not of
into or through the system.
plant or animal origin.
hydrostatic roof system, n—a roof system that is capable of
iso—in roofing, see polyisocyanurate foam board.
holding water without allowing water to penetrate the
isoboard—See polyisocyanurate foam board.
system.
insulation—See thermal insulation.
hygroscopic, adj—attracting, absorbing, and retaining atmo-
kerosine number, n—the millilitres of kerosine held per 100 g
spheric moisture.
of felt as determined by Test Method D6136/D6136M.To
obtain the percentage saturating capacity of the felt for any
ice dam, n—amasso
...

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.
´1
Designation: D1079 − 18 D1079 − 20
Standard Terminology Relating to
Roofing and Waterproofing
This standard is issued under the fixed designation D1079; 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.
ε NOTE—Editorially added parts of speech throughout in February 2019.
1. Referenced Documents
1.1 ASTM Standards:
C33/C33M Specification for Concrete Aggregates
C591 Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
C1289 Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board
D312/D312M Specification for Asphalt Used in Roofing
D450/D450M Specification for Coal-Tar Pitch Used in Roofing, Dampproofing, and Waterproofing
3 3
D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft (600 kN-m/m ))
D1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft (2,700
kN-m/m ))
D2822/D2822M Specification for Asphalt Roof Cement, Asbestos-Containing (Withdrawn 2016)
D4586/D4586M Specification for Asphalt Roof Cement, Asbestos-Free
D6136/D6136M Test Method for Kerosine Number of Unsaturated (Dry) Felt by Vacuum Method
2. Terminology
2.1 Definitions:
accelerated weathering, v—the exposure of a specimen to a specified test environment for a specified time with the intent of
producing, in a shorter time period, effects similar to actual weathering.
aggregate, n—(1) crushed stone, crushed slag, or water-worn gravel used for surfacing a built-up roof; (2) any granular mineral
material.
alligatoring, v—the cracking of the surfacing bitumen on a built-up roof, producing a pattern of cracks similar to an alligator’s
hide; the cracks may not extend through the surfacing bitumen.
anionic emulsion, n—an emulsion in which the emulsifying system establishes a predominance of negative charges on the
discontinuous phase.
application rate, n—the quantity (mass, volume or thickness) of material applied per unit area.
artificial weathering, v—exposure to conditions, which may be cyclic, involving temperature, relative humidity, radiant energy,
and/or any other conditions or pollutants found in the atmosphere in various geographical areas, which may accelerate changes
in properties of materials over those of natural weather conditions.
asbestos, n—a group of natural fibrous impure silicate materials.
asphalt, n—a dark brown to black cementitious material in which the predominating constituents are bitumens that occur in nature
or are obtained in petroleum processing.
asphalt, air blown, n—an asphalt produced by blowing air through molten asphalt at an elevated temperature to raise its softening
point and modify other properties.
This terminology is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.01 on
Nomenclature, Definitions and Editorial.
Current edition approved Dec. 15, 2018May 1, 2020. Published January 2019June 2020. Originally approved in 1950. Last previous edition approved in 20162018 as
D1079 – 16.D1079 – 18. DOI: 10.1520/D1079-18E01.10.1520/D1079-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1079 − 20
asphaltene, n—a high molecular weight hydrocarbon fraction precipitated from asphalt by a designated paraffinic naphtha solvent
at a specified temperature and solvent-asphalt ratio.
DISCUSSION—
The asphaltene fraction should be identified by the temperature and solvent-asphalt ratio used.
asphalt felt, n—an asphalt-saturated felt.
asphaltite, n—a natural asphalt found below ground level.
asphalt mastic, n—a mixture of asphaltic material and graded mineral aggregate that can be poured when heated, but requires
mechanical manipulation to apply.
asphalt rock (rock asphalt), n—a naturally occurring rock formation, usually limestone or sandstone, containing throughout its
mass a minor amount of asphalt.
asphalt roof cement, n—a trowelable mixture of asphalt, solvents, mineral stabilizers, fillers or fibers, or both. See Specifications
D2822/D2822M and D4586/D4586M.
asphalt roof cement, n—see flashing cement.
asphalt, steam blown, n—an asphalt produced by blowing steam through molten asphalt to modify its properties.
backnailing, v—the practice of blind-nailing roofing felts to a substrate in addition to hot-mopping to prevent slippage.
bald roof—See smooth-surfaced roof.
base ply, n—the bottom or first ply in a built-up roofing membrane when additional plies are to be subsequently installed.
base sheet, n—a product intended to be used as a base ply in a built-up roofing system.
bitumen, n—(1) a class of amorphous, black or dark-colored, (solid, semi-solid, or viscous) cementitious substances, natural or
manufactured, composed principally of high molecular weight hydrocarbons, soluble in carbon disulfide, and found in asphalts,
tars, pitches, and asphaltites; (2) a generic term used to denote any material composed principally of bitumen.
bitumen trap—See pitch pocket.
bituminized, adj—impregnated with bitumen. Example: bituminized fiber pipe.
bituminous, adj—containing or treated with bitumen. Examples: bituminous concrete, bituminous felts and fabrics, bituminous
pavement.
bituminous emulsion, n—(1) a suspension of minute globules of bituminous material in water or in an aqueous solution; (2) a
suspension of minute globules of water or of an aqueous solution in a liquid bituminous material (invert emulsion).
bituminous grout, n—a mixture of bituminous material and fine sand that will flow into place without mechanical manipulation
when heated.
blast-furnace slag, n—the nonmetallic product, consisting essentially of silicates and alumino-silicates of calcium and other bases,
that is developed in a molten condition simultaneously with iron in a blast furnace.
blind nailing, v—the use of nails that are not exposed to the weather in the finished roofing.
blister, n—(1) a raised portion of a roofing membrane resulting from local internal pressure; (2) the similarly formed protuberances
in coated prepared roofing.
blocking, n—(1) wood built into a roofing system above the deck and below the membrane and flashing to (a) stiffen the deck
around an opening, (b) act as a stop for insulation, (c) serve as a nailer for attachment of the membrane or flashing.
(2) wood cross-members installed between rafters or joists to provide support at cross-joints between deck panels.
(3) cohesion or adhesion between similar or dissimilar materials in roll or sheet form that may interfere with the satisfactory
and efficient use of the material.
blueberry—See strawberry.
bond, n—the adhesive and cohesive forces holding two roofing components in intimate contact.
brooming, v—embedding a ply by using a broom to smooth it out and ensure contact with the adhesive under the ply.
built-up roofing, n—a continuous, semiflexible membrane consisting of plies of saturated felts, coated felts, fabrics or mats
assembled in place with alternate layers of bitumen, and surfaced with mineral aggregate, bituminous materials, or a granule
surfaced sheet (abbreviation, BUR).
D1079 − 20
cant strip, n—a beveled strip used under flashings to modify the angle at the point where the roofing or waterproofing membrane
meets any vertical element.
cap flashing—See flashing.
cap sheet, n—a granule-surfaced coated felt used as the top ply of a built-up roofing membrane.
cationic emulsion, n—an emulsion in which the emulsifying system establishes a predominance of positive charges on the
discontinuous phase.
caulking, n—a composition of vehicle and pigment, used at ambient temperatures for filling joints, that remains plastic for an
extended time after application.
channel mopping—See mopping, (3) strip.
coal tar, n—a dark brown to black cementitious material produced by the destructive distillation of coal.
coal tar roof cement, n—a trowelable mixture of processed coal tar base, solvents, mineral fillers or fibers, or both.
coal-tar felt, n—a felt that has been saturated with refined coal tar.
coal-tar pitch, n—a dark brown to black, solid cementitious material obtained as residue in the partial evaporation or distillation
of coal tar.
coated sheet (or felt), n—(1) an asphalt felt that has been coated on both sides with harder, more viscous asphalt; (2) a glass fiber
felt that has been simultaneously impregnated and coated with asphalt on both sides.
coke-oven tar—See coal tar.
cold-process roofing, n—a continuous, semiflexible membrane consisting of plies of felts, mats, or fabrics laminated on a roof with
alternate layers of roof cement and surfaced with a cold-applied coating.
concealed membrane waterproofing, n—also referred to as structural slab waterproofing; (1) for below grade: refers to a form
of waterproofing where the membrane is applied to the mud mat and later covered with a topping, usually concrete, to act as
a wearing layer or course, and (2) for elevated structural concrete deck: applied over the structural surface and covered/concealed
by other components such as a topping slab, pavers, ballast, pavement, and plantings.
condensation, n—the conversion of water vapor or other gas to liquid as the temperature drops or atmospheric pressures rises. (See
also dew point).
conditioning, v—the storage of a specimen under specified temperature, humidity, etc., for a specified time prior to testing.
conductance, thermal, n—the thermal transmission in unit time through unit area of a particular body or assembly having defined
2 2
surfaces, when unit average temperature difference is established between the surfaces. C = W ⁄m ·K (C = Btu ⁄h·ft ·°F).
conductivity, thermal, n—the thermal transmission, by conduction only, in unit time through unit area between two isothermal
surfaces of an infinite slab of a homogeneous material of unit thickness, in a direction perpendicular to the surface, when unit
temperature difference is established between the surfaces. k = W ⁄m·K (k = Btu·in. ⁄h·ft ·°F).
cone penetration—See penetration.
coping, n—a covering on top of a wall exposed to the weather, usually sloped to carry off water.
counterflashing, n—formed metal or elastomeric sheeting secured on or into a wall, curb, pipe, roof-top unit, or other surface, to
cover and protect the upper edge of a base flashing and its associated fasteners.
coverage, n—the surface area to be continuously covered by a specific quantity of a particular material.
creep, n—the time-dependent part of a strain resulting from stress.
cricket, n—a construction to divert water around or away from a chimney, curb, wall, expansion joint, or other penetration. (See
saddle).
crushed stone, n—the product resulting from the artificial crushing of rocks, boulders, or large cobblestones, substantially all faces
of which have resulted from the crushing operation.
cutback, n—solvent-thinned bitumen used in cold-process roofing adhesives, flashing cements, and roof coatings.
cutoff, n—a detail designed to prevent lateral water movement into the insulation where the membrane terminates at the end of
a day’s work, or used to isolate sections of the roofing system. It is usually removed before the continuation of the work.
dampproofing, v—treatment of a surface or structure to resist the passage of water in the absence of hydrostatic pressure.
dead level, adj—absolutely horizontal, or zero slope (see also slope).
D1079 − 20
dead level asphalt, n—a roofing asphalt conforming to the requirements of Specification D312/D312M, Type I.
dead level roofing, n—a roofing system applied on a surface with a 0 to 2 % incline.
deck, n—the structural surface to which the roofing or waterproofing system (including insulation) is applied.
direction change, n—a change in the orientation of the principal dimension or of the support of adjoining units of the roofing
system.
double pour, v—to apply two layers of aggregate and bitumen to a built-up roof.
dry felt, n—(1) see felt; (2) a felt which has not been saturated with bitumen.
edge stripping, v—application of felt strips cut to narrower widths than the normal felt-roll width to cover a joint between flashing
and built-up roofing.
edge venting, v—the practice of providing regularly spaced protected openings at a roof perimeter to relieve water vapor pressure
in the insulation.
elastomer, n—a macromolecular material that returns rapidly to its approximate initial dimensions and shape after substantial
deformation by a weak stress and subsequent release of that stress.
embedment, v—(1) the process of pressing a felt, aggregate, fabric, mat, or panel uniformly and completely into hot bitumen or
adhesive to ensure intimate contact at all points; (2) the process of pressing granules into coating in the manufacture of
factory-prepared roofing, such as shingles.
emulsion, n—an intimate mixture of bitumen and water, with uniform dispersion of the bitumen or water globules, usually
stabilized by an emulsifying agent or system.
envelope, n—a continuous membrane edge seal formed at the perimeter and at penetrations by folding the base sheet or ply over
the plies above and securing it to the top of the membrane. The envelope prevents bitumen seepage from the edge of the
membrane.
equilibrium moisture content, n—(1) the moisture content of a material stabilized at a given temperature and relative humidity,
expressed as percent moisture by weight; (2) the typical moisture content of a material in any given geographical area.
equiviscous temperature (EVT), n—the temperature at which a bitumen attains the proper viscosity for built-up membrane
application. EVT may or may not be applicable to polymer modified bituminous sheet materials. (See EVT for asphalt and EVT
for coal tar).
DISCUSSION—
In England, EVT is the temperature corresponding to a standard efflux time from a road tar viscometer.
equiviscous temperature for asphalt, n—the equiviscous temperature (EVT) for roofing asphalt (Specification D312/D312M,
Type I, II, III, or IV) is as follows: (1) mop application—the temperature at which the asphalt’s apparent viscosity is 125 cP.
(2) mechanical spreader application—the temperature at which the asphalt’s apparent viscosity is 75 cP. See equiviscous
temperature and EVT application range.
equiviscous temperature for coal tar, n—the equiviscous temperature (EVT) for roofing coal tar (Specification D450/D450M,
Type I or III) is the temperature at which the coal tar’s apparent viscosity is 25 cP. See equiviscous temperature and EVT
application range.
EVT application range, n—the bitumen application temperature range. The range is from 25°F25 °F below the EVT to 25°F25 °F
above the EVT (50°F(50 °F span). The temperature is measured in the mop cart or mechanical spreader just prior to the
application of bitumen to the substrate.
expansion joint, n—a structural separation between two building elements that allows free movement between the elements
without damage to the roofing or waterproofing system.
exposure, n—(1) the transverse dimension of a roofing element not overlapped by an adjacent element in any roofing system. The
exposure of any ply in a membrane may be computed by dividing the felt width minus 51 mm (2 in.), by the number of shingled
plies; thus, the exposure of a 914-mm (36-in.) wide felt in a shingled, four-ply membrane should be 216 mm (8 ⁄2 in.); (2) the
time during which a portion of a roofing element is exposed to the weather.
extra-steep asphalt—See super-steep asphalt.
fabric, n—a woven or nonwoven cloth of organic or inorganic filaments, threads, or yarns.
D1079 − 20
facer, n—the outermost, adhered top or bottom, or both, sheet (or layer) of an insulation board that is comprised of a different
material than the insulation itself. It is commonly composed of organic paper, glass mat, or a combination thereof, generally
impregnated or coated, or both, with asphalt, latex, or the like; or metal foil.
2 2
factory square, n—10 m (108 ft ).
fallback, n—a reduction in bitumen softening point, sometimes caused by refluxing or overheating in a relatively closed container.
(See also softening point drift).
felt, n—a flexible sheet manufactured by the interlocking of fibers with a binder or through a combination of mechanical work,
moisture, and heat. Felts are manufactured principally from vegetable fibers (organic felts), asbestos fibers (asbestos felts) or
glass fibers (glass fiber felts); other fibers may be present in each type.
felt layer, n—(1) a machine used for applying bitumen and built-up roofing felts; (2) See ply.
felt mill ream, n—the mass in pounds of 480 ft of dry, unsaturated felt, also termed “point weight.”
fine mineral surfacing, n—water-insoluble inorganic material, more than 50 % of which passes the 500-μm (No. 35) sieve, used
on the surface of roofing.
finger blisters, n—finger shaped blisters or wrinkles in the plies of a built-up roofing or waterproofing membrane.
finger wrinkles—See finger blisters.
fishmouth, n—(1) a half-cylindrical or half-conical opening formed by an edge wrinkle or failure to embed a roofing felt; (2) in
shingles, a half-conical opening formed at a cut edge.
flashing, n—the system used to seal membrane edges at walls, expansion joints, drains, gravel stops, and other places where the
membrane is interrupted or terminated. Base flashing covers the edges of the membrane. Cap or counterflashing shields the upper
edges of the base flashing.
flashing cement, n—a trowelable mixture of cutback bitumen and mineral stabilizers including asbestos or other inorganic fibers.
flat asphalt, n—a roofing asphalt conforming to the requirements of Specification D312/D312M, Type II.
flood coat, n—the top layer of bitumen used to hold the aggregate on an aggregate-surfaced, built-up roofing membrane.
fluid-applied elastomer, n—an elastomeric material, fluid at ambient temperature, that dries or cures after application to form a
continuous membrane. Such systems normally do not incorporate reinforcement.
flux, n—a bituminous material used as a feed stock for further processing and as a material to soften other bituminous materials.
“free carbon” in tars, n—the hydrocarbon fraction that is precipitated from a tar by dilution with carbon disulfide.
glass felt, n—glass fibers bonded into a sheet with resin and suitable for impregnation in the manufacture of bituminous
waterproofing, roofing membranes, and shingles.
glass mat, n—a thin mat of glass fibers with or without a binder.
glaze coat, n—(1) the top layer of asphalt in a smooth-surfaced built-up roof assembly; (2) a thin protective coating of bitumen
applied to the lower plies or top ply of a built-up membrane, when application of additional felts, or the flood coat and aggregate
surfacing are delayed.
granule—See mineral granules.
gravel, n—coarse, granular aggregate, with pieces larger than sand grains, resulting from the natural erosion of rock.
gravel in, v—to spread aggregate into hot bitumen on the surface of the roofing membrane.
gravel stop, n—a flanged device, frequently metallic, designed to prevent loose aggregate from washing off the roof and to provide
a continuous finished edge for the roofing.
headlap, n—in roofing, for products installed in a shingle fashion, the area on a shingle or sheet material that is covered by the
requisite number of layers in multiply construction; for example, two layers on a strip shingle or three layers in a three-ply
built-up roof. Headlap is commonly referred to by its width, thus the designation by linear dimension. For multiple sheet roofing,
see Fig. 1. For shingles, see Fig. 2.
heat exposure, v—the process of subjecting a specimen to an elevated temperature at atmospheric pressure for a specified period
of time with the intent of determining properties by subsequent testing.
holiday—an area where a liquid-applied material is missing.
D1079 − 20
FIG. 1 Headlap in Multiple Sheet Roofing
“hot stuff” or “hot”, n—a roofer’s term for hot bitumen.
hydrokinetic roof system, n—a roof system that depends on quick drainage via water shedding to prevent water entry into or
through the system.
hydrostatic roof system, n—a roof system that is capable of holding water without allowing water to penetrate the system.
hygroscopic, adj—attracting, absorbing, and retaining atmospheric moisture.
ice dam, n—a mass of ice formed at the transition from a warm to a cold roof surface. Frequently formed by refreezing meltwater
at the overhang of a steep roof, an ice dam may cause ice and water to back up under shingles or other roofing materials.
impregnate, v—in roofing materials manufacture, to completely surround the fibers in a felt or mat with bitumen, with t
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