ASTM C898/C898M-09(2017)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C898/C898M − 09 (Reapproved 2017)
Standard Guide for
Use of High Solids Content, Cold Liquid-Applied
Elastomeric Waterproofing Membrane with Separate
Wearing Course
This standard is issued under the fixed designation C898/C898M; 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 C836/C836M Specification for High Solids Content, Cold
Liquid-Applied Elastomeric Waterproofing Membrane for
1.1 This guide describes the use of a high solids content,
Use with Separate Wearing Course
cold liquid-applied elastomeric waterproofing membrane that
C920 Specification for Elastomeric Joint Sealants
meets the criteria in Specification C836/C836M, in a water-
C1193 Guide for Use of Joint Sealants
proofing system subject to hydrostatic pressure for building
C1299 Guide for Use in Selection of Liquid-Applied Seal-
decks over occupied space where the membrane is covered
ants (Withdrawn 2012)
with a separate protective wearing course.
C1471/C1471M Guide for the Use of High Solids Content
1.2 The values stated in either SI units or inch-pound units
Cold Liquid-Applied Elastomeric Waterproofing Mem-
are to be regarded separately as standard. The values stated in
brane on Vertical Surfaces
each system may not be exact equivalents; therefore, each
C1472 Guide for Calculating Movement and Other Effects
system shall be used independently of the other. Combining
When Establishing Sealant Joint Width
values from the two systems may result in non-conformance
D1056 Specification for Flexible Cellular Materials—
with the standard.
Sponge or Expanded Rubber
1.3 This standard does not purport to address all of the D1751 Specification for Preformed Expansion Joint Filler
safety concerns, if any, associated with its use. It is the
for Concrete Paving and Structural Construction (Nonex-
responsibility of the user of this standard to establish appro- truding and Resilient Bituminous Types)
priate safety, health, and environmental practices and deter-
D1752 Specification for Preformed Sponge Rubber Cork
mine the applicability of regulatory limitations prior to use. and Recycled PVC Expansion Joint Fillers for Concrete
1.4 This international standard was developed in accor- Paving and Structural Construction
dance with internationally recognized principles on standard-
D5295 Guide for Preparation of Concrete Surfaces for Ad-
ization established in the Decision on Principles for the hered (Bonded) Membrane Waterproofing Systems
Development of International Standards, Guides and Recom-
D5957 Guide for Flood Testing Horizontal Waterproofing
mendations issued by the World Trade Organization Technical Installations
Barriers to Trade (TBT) Committee.
D6134 Specification for Vulcanized Rubber Sheets Used in
Waterproofing Systems
2. Referenced Documents
D6451/D6451M Guide for Application of Asphalt Based
Protection Board
2.1 ASTM Standards:
C33/C33M Specification for Concrete Aggregates D6506 Specification for Asphalt Based Protection Board for
Below-Grade Waterproofing
C578 Specification for Rigid, Cellular Polystyrene Thermal
Insulation E1907 Guide to Methods of Evaluating Moisture Conditions
of Concrete Floors to Receive Resilient Floor Coverings
C717 Terminology of Building Seals and Sealants
(Withdrawn 2008)
1 2.2 American Concrete Institute Standard:
This guide is under the jurisdiction of ASTM Committee D08 on Roofing and
ACI 301 Specifications for Structural Concrete for Build-
Waterproofing and is the direct responsibility of Subcommittee D08.22 on Water-
proofing and Dampproofing Systems.
ings
Current edition approved Dec. 1, 2017. Published December 2017. Originally
approved in 1978. Last previous edition approved in 2009 as C898/C898M – 09.
DOI: 10.1520/C0898_C0898M-09R17.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available from ACI International, P.O. Box 9094, Farmington Hills, MI
the ASTM website. 4833-9094.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C898/C898M − 09 (2017)
3. Terminology 3.2.10 structural slab—a horizontal, supporting, cast-in-
place, concrete building deck. See Fig. 1.
3.1 For definitions of terms used in the guide, refer to
3.2.11 troweled finish—a concrete finish provided by
Terminology C717.
smoothing the surface with power driven or hand trowels or
3.2 Definitions of Terms Specific to This Standard:
both, after the float finishing operation. A troweled finish is
3.2.1 cold-applied—capable of being applied without heat-
smoother than the floated finish. For specifications, see ACI
ing as contrasted to hot-applied. Cold-applied products are
301.
furnished in a liquid state, whereas hot-applied products are
3.2.12 wearing surface—a surface exposed to traffic, either
furnished as solids that must be heated to liquefy them.
pedestrian or vehicular, also described as finish wearing
3.2.2 curing time—the period between application and the
surface.
time when the material reaches its design physical properties.
3.2.13 wet-film thickness—the thickness of a liquid coating
3.2.3 deflection—the deviation of a structural element from
as it is applied.
its original shape or plane due to physical loading, temperature
gradients, or rotation of its supports.
3.2.14 wet-film gage—a gage for measuring the thickness of
a wet film.
3.2.4 drainage board—see prefabricated drainage
composite, the preferred term.
4. Significance and Use
3.2.5 drainage course—see percolation layer and Fig. 1.
4.1 Designers and installers of waterproofing systems may
3.2.6 flashing—a generic term describing the transitional
consult this guide for a discussion of important elements of the
area between the waterproofing membrane and surfaces above
use of cold liquid-applied waterproofing membranes and asso-
the wearing surface of the building deck; a terminal closure or
ciated elements of construction. This guide is not intended to
barrier to prevent ingress of water into the system.
serve as a specification for waterproofing installation.
3.2.7 freeze-thaw cycle—the freezing and subsequent thaw-
4.2 Long-term performance of waterproofing with a sepa-
ing of a material.
rate wearing course is important because of the substantial
3.2.8 percolation layer (drainage course)—a layer of
difficulty in determining the location of leakage and in remov-
washed gravel or of a manufactured drainage media that allows
ing overlying materials to make repairs.
water to filter through to the drain (see Fig. 1).
4.3 Refer to Guide C1471/C1471M for application on
3.2.9 prefabricated drainage composite—proprietary de-
below grade walls and vertical surfaces.
vices to facilitate drainage, usually a composite laminate of
more than one material including filter fabric.
5. General
5.1 Major Components, Subsystems, and Features—The
major components to be considered for a building deck
waterproofing system are the structural building deck or
substrate to be waterproofed, waterproofing membrane, protec-
tion of the membrane, drainage, insulation, and wearing course
(see Fig. 1). Additional features to be considered are membrane
terminal conditions and expansion joints.
5.2 Compatibility—It is essential that all components and
contiguous elements be compatible and coordinated to form a
totally integrated waterproofing system.
6. Substrate
6.1 General—The building deck or substrate referred to in
this guide is reinforced cast-in-place structural concrete. Pre-
cast concrete slabs pose more technical problems than cast-in-
place concrete, and the probability of lasting watertightness is
greatly diminished and difficult to achieve because of the
multitude of joints which have the capability of movement and
must be treated accordingly. Moving joints are critical features
of waterproofing systems and are more critical when sealed at
the membrane level than at a higher level with the use of
integral concrete curbs. Such curbs are impractical with precast
concrete slabs and necessitate an even more impractical drain
in each slab. Other disadvantages of precast concrete slabs are
their inflexibility in achieving contoured slope to drains and the
FIG. 1 Basic Components of Cold Liquid-Applied Elastomeric
Membrane Waterproofing System with Separate Wearing Course difficulty of coordinating the placement of such drains.
C898/C898M − 09 (2017)
6.2 Strength—The strength of concrete is a factor to be additional cracks and provides a cleavage plane between the fill
considered with respect to the liquid-applied membrane insofar and structural slab. This cleavage plane complicates the detec-
as it relates to finish, bond strength, and continuing integrity tion of leakage in the event that water should penetrate the
(absence of cracks and other defects that could affect the membrane at a crack in the fill and travel along the separation
integrity of the membrane after installation). until reaching a crack in the structural slab.
6.3 Density and Moisture Content—Density of concrete and 6.7 Finish—The structural slab should have a finish that
facilitates proper application of the liquid-applied membrane.
moisture content when cured are interrelated and can affect
adhesion of the membrane to the substrate with an excessively The surface should be of sufficiently rough texture to provide
a mechanical bond for the membrane but not so rough as to
high moisture content, moisture may condense at the mem-
brane and concrete interface and cause membrane delamina- preclude achieving continuity of the membrane of the specified
thickness across the surface. A typical manufacturer’s recom-
tion. This is particularly so if the top surface is cooler than the
concrete below. Lower moisture contents are achieved with the mendation is a steel-troweled finish, followed by a fine hair
broom.
use of hard, dense, stone aggregate. This type of coarse
aggregate will generally provide structural concrete with a 6.7.1 Concrete surfaces shall be free of laitance, loose
aggregate, sharp projections, grease, oil, dirt, curing
moisture content from 3 to 5 % when cured. Lightweight
aggregate, such as expanded shale, will generally provide compounds, or other contaminants that could affect the com-
plete bonding of the liquid-applied membrane to the concrete
lightweight structural concrete with a moisture content from 5
to 20 % when cured. Lightweight insulating concrete made surface. For preparation and acceptance of concrete surfaces,
refer to Guide D5295. Application shall not proceed until all
with a weaker expanded aggregate, such as perlite, has a
relatively low compressive strength and can contain over 20 % protrusions and projections through the structural slab are in
place, or sleeves placed through the slab, and provision has
moisture when cured. The concrete used for the substrate
3 3
should have a minimum density of 1762 kg/m [110 lb/ft ] and been made to secure their watertightness. Concrete surfaces
shall be visibly dry and pass any additional dryness tests
have a maximum moisture content of 8 % when cured. From
this it can be seen that only certain lightweight aggregates can recommended by the liquid-applied membrane manufacturer
prior to application.
be considered for use and no lightweight insulating aggregates
can be used.
6.8 Curing—Curing of the structural slab is necessary to
provide a sound concrete surface and to obtain the quality of
6.4 Admixtures, Additives, and Cement/Concrete Modifiers
concrete required. The concrete should be cured a minimum of
—Admixtures, additives, and modifiers serve many functions
7 days and aged a minimum of 28 days including curing time,
in mixing, forming, and curing concrete, such as to retard or
before application of the liquid-applied membrane. Curing is
accelerate the cure rate; reduce the water content required;
accomplished chemically with moisture and should not be
entrain air; increase strength; create or improve the ability of
construed as drying.
the concrete to bond to existing, cured concrete; permit thin
6.8.1 Moist Curing—Moist curing is achieved by keeping
topping overlayers; and improve workability. Some admixtures
and modifiers (particularly polymeric, latex, or other organic the surfaces continuously wet by covering them with burlap
saturated with water and kept wet by spraying or hosing. The
chemical based materials) may coat the concrete particles and
reduce the ability of the waterproofing membrane to bond to covering material should be placed to provide complete surface
the concrete. The membrane manufacturer should be consulted coverage with joints lapped a minimum of 75 mm [3 in.].
if the concrete used for the deck will contain any admixtures, 6.8.2 Sheet Curing—Sheet curing is accomplished with a
additives, or modifiers in order to determine the compatibility
sheet vapor retarder that reduces the loss of water from the
of the membrane with the concrete. concrete and moistens the surface of concrete by condensation,
preventing the surface from drying while curing. Laps of sheets
6.5 Underside Liner and Coating—The underside of the
covering the slab should not be less than 50 mm [2 in.] and
concrete deck should not have an impermeable barrier. A metal
should be sealed or weighted.
liner or coating that forms a vapor barrier on the underside can
6.8.3 Chemical Curing—Liquid or chemical curing com-
trap moisture in the concrete and destroy or prevent the
pounds should not be used unless approved by the manufac-
adhesive bond of the membrane to the upper surface of the
turer of the liquid-applied membrane as the material may
concrete. Uniformly spaced perforations in metal liners may
interfere with the bond of the membrane to the structural slab.
provide a solution to the vapor barrier problem but as yet there
are no definitive data on the requirements for the size and 6.9 Dryness—Comply with membrane manufacturer’s re-
spacing of the perforations. It should also be recognized that
quirements for substrate dryness. For methods for testing
this method would preclude any painting of the metal liner moisture content, refer to Guide E1907.
after the concrete is poured on it.
6.10 Joints—Joints in a structural concrete slab in this guide
6.6 Slope for Drainage—Drainage at the memb
...

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: C898/C898M − 09 C898/C898M − 09 (Reapproved 2017)
Standard Guide for
Use of High Solids Content, Cold Liquid-Applied
Elastomeric Waterproofing Membrane with Separate
Wearing Course
This standard is issued under the fixed designation C898/C898M; 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 guide describes the use of a high solids content, cold liquid-applied elastomeric waterproofing membrane that meets
the criteria in Specification C836C836/C836M, in a waterproofing system subject to hydrostatic pressure for building decks over
occupied space where the membrane is covered with a separate protective wearing course.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C33C33/C33M Specification for Concrete Aggregates
C578 Specification for Rigid, Cellular Polystyrene Thermal Insulation
C717 Terminology of Building Seals and Sealants
C836C836/C836M Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use
with Separate Wearing Course
C920 Specification for Elastomeric Joint Sealants
C1193 Guide for Use of Joint Sealants
C1299 Guide for Use in Selection of Liquid-Applied Sealants (Withdrawn 2012)
C1471C1471/C1471M Guide for the Use of High Solids Content Cold Liquid-Applied Elastomeric Waterproofing Membrane
on Vertical Surfaces
C1472 Guide for Calculating Movement and Other Effects When Establishing Sealant Joint Width
D1056 Specification for Flexible Cellular Materials—Sponge or Expanded Rubber
D1751 Specification for Preformed Expansion Joint Filler for Concrete Paving and Structural Construction (Nonextruding and
Resilient Bituminous Types)
D1752 Specification for Preformed Sponge Rubber Cork and Recycled PVC Expansion Joint Fillers for Concrete Paving and
Structural Construction
D5295 Guide for Preparation of Concrete Surfaces for Adhered (Bonded) Membrane Waterproofing Systems
D5957 Guide for Flood Testing Horizontal Waterproofing Installations
This guide is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.22 on Waterproofing
and Dampproofing Systems.
Current edition approved June 15, 2009Dec. 1, 2017. Published July 2009December 2017. Originally approved in 1978. Last previous edition approved in 20012009 as
C898 – 01.C898/C898M – 09. DOI: 10.1520/C0898_C0898M-09.10.1520/C0898_C0898M-09R17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C898/C898M − 09 (2017)
D6134 Specification for Vulcanized Rubber Sheets Used in Waterproofing Systems
D6451D6451/D6451M Guide for Application of Asphalt Based Protection Board
D6506 Specification for Asphalt Based Protection Board for Below-Grade Waterproofing
E1907 Guide to Methods of Evaluating Moisture Conditions of Concrete Floors to Receive Resilient Floor Coverings
(Withdrawn 2008)
2.2 American Concrete Institute Standard:
ACI 301 Specifications for Structural Concrete for Buildings
3. Terminology
3.1 For definitions of terms used in the guide, refer to Terminology C717.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 cold-applied—capable of being applied without heating as contrasted to hot-applied. Cold-applied products are furnished
in a liquid state, whereas hot-applied products are furnished as solids that must be heated to liquefy them.
3.2.2 curing time—the period between application and the time when the material reaches its design physical properties.
3.2.3 deflection—the deviation of a structural element from its original shape or plane due to physical loading, temperature
gradients, or rotation of its supports.
3.2.4 drainage board—see prefabricated drainage composite, the preferred term.
3.2.5 drainage course—see percolation layer and Fig. 1.
3.2.6 flashing—a generic term describing the transitional area between the waterproofing membrane and surfaces above the
wearing surface of the building deck; a terminal closure or barrier to prevent ingress of water into the system.
3.2.7 freeze-thaw cycle—the freezing and subsequent thawing of a material.
3.2.8 percolation layer (drainage course)—a layer of washed gravel or of a manufactured drainage media that allows water to
filter through to the drain (see Fig. 1).
3.2.9 prefabricated drainage composite—proprietary devices to facilitate drainage, usually a composite laminate of more than
one material including filter fabric.
3.2.10 structural slab—a horizontal, supporting, cast-in-place, concrete building deck. See Fig. 1.
FIG. 1 Basic Components of Cold Liquid-Applied Elastomeric Membrane Waterproofing System with Separate Wearing Course
Available from ACI International, P.O. Box 9094, Farmington Hills, MI 4833-9094.
C898/C898M − 09 (2017)
3.2.11 troweled finish—a concrete finish provided by smoothing the surface with power driven or hand trowels or both, after
the float finishing operation. A troweled finish is smoother than the floated finish. For specifications, see ACI 301.
3.2.12 wearing surface—a surface exposed to traffic, either pedestrian or vehicular, also described as finish wearing surface.
3.2.13 wet-film thickness—the thickness of a liquid coating as it is applied.
3.2.14 wet-film gage—a gage for measuring the thickness of a wet film.
4. Significance and Use
4.1 Designers and installers of waterproofing systems may consult this guide for a discussion of important elements of the use
of cold liquid-applied waterproofing membranes and associated elements of construction. This guide is not intended to serve as
a specification for waterproofing installation.
4.2 Long-term performance of waterproofing with a separate wearing course is important because of the substantial difficulty
in determining the location of leakage and in removing overlying materials to make repairs.
4.3 Refer to Guide C1471C1471/C1471M for application on below grade walls and vertical surfaces.
5. General
5.1 Major Components, Subsystems, and Features—The major components to be considered for a building deck waterproofing
system are the structural building deck or substrate to be waterproofed, waterproofing membrane, protection of the membrane,
drainage, insulation, and wearing course (see Fig. 1). Additional features to be considered are membrane terminal conditions and
expansion joints.
5.2 Compatibility—It is essential that all components and contiguous elements be compatible and coordinated to form a totally
integrated waterproofing system.
6. Substrate
6.1 General—The building deck or substrate referred to in this guide is reinforced cast-in-place structural concrete. Precast
concrete slabs pose more technical problems than cast-in-place concrete, and the probability of lasting watertightness is greatly
diminished and difficult to achieve because of the multitude of joints which have the capability of movement and must be treated
accordingly. Moving joints are critical features of waterproofing systems and are more critical when sealed at the membrane level
than at a higher level with the use of integral concrete curbs. Such curbs are impractical with precast concrete slabs and necessitate
an even more impractical drain in each slab. Other disadvantages of precast concrete slabs are their inflexibility in achieving
contoured slope to drains and the difficulty of coordinating the placement of such drains.
6.2 Strength—The strength of concrete is a factor to be considered with respect to the liquid-applied membrane insofar as it
relates to finish, bond strength, and continuing integrity (absence of cracks and other defects that could affect the integrity of the
membrane after installation).
6.3 Density and Moisture Content—Density of concrete and moisture content when cured are interrelated and can affect
adhesion of the membrane to the substrate with an excessively high moisture content, moisture may condense at the membrane
and concrete interface and cause membrane delamination. This is particularly so if the top surface is cooler than the concrete below.
Lower moisture contents are achieved with the use of hard, dense, stone aggregate. This type of coarse aggregate will generally
provide structural concrete with a moisture content from 3 to 5 % when cured. Lightweight aggregate, such as expanded shale, will
generally provide lightweight structural concrete with a moisture content from 5 to 20 % when cured. Lightweight insulating
concrete made with a weaker expanded aggregate, such as perlite, has a relatively low compressive strength and can contain over
3 3
20 % moisture when cured. The concrete used for the substrate should have a minimum density of 1762 kg/m (110[110 lb/ft )]
and have a maximum moisture content of 8 % when cured. From this it can be seen that only certain lightweight aggregates can
be considered for use and no lightweight insulating aggregates can be used.
6.4 Admixtures, Additives, and Cement/Concrete Modifiers —Admixtures, additives, and modifiers serve many functions in
mixing, forming, and curing concrete, such as to retard or accelerate the cure rate; reduce the water content required; entrain air;
increase strength; create or improve the ability of the concrete to bond to existing, cured concrete; permit thin topping overlayers;
and improve workability. Some admixtures and modifiers (particularly polymeric, latex, or other organic chemical based materials)
may coat the concrete particles and reduce the ability of the waterproofing membrane to bond to the concrete. The membrane
manufacturer should be consulted if the concrete used for the deck will contain any admixtures, additives, or modifiers in order
to determine the compatibility of the membrane with the concrete.
6.5 Underside Liner and Coating—The underside of the concrete deck should not have an impermeable barrier. A metal liner
or coating that forms a vapor barrier on the underside can trap moisture in the concrete and destroy or prevent the adhesive bond
of the membrane to the upper surface of the concrete. Uniformly spaced perforations in metal liners may provide a solution to the
vapor barrier problem but as yet there are no definitive data on the requirements for the size and spacing of the perforations. It
should also be recognized that this method would preclude any painting of the metal liner after the concrete is poured on it.
C898/C898M − 09 (2017)
6.6 Slope for Drainage—Drainage at the membrane level is important. When the waterproofing membrane is placed directly on
the concrete slab a monolithic concrete substrate slope of a minimum 2 % ([ ⁄4 in./ft)in./ft] should be maintained. Slope is best
achieved with a monolithic structural slab and not with a separate concrete fill layer. The fill presents the potential of additional
cracks and provides a cleavage plane between the fill and structural slab. This cleavage plane complicates the detection of leakage
in the event that water should penetrate the membrane at a crack in the fill and travel along the separation until reaching a crack
in the structural slab.
6.7 Finish—The structural slab should have a finish that facilitates proper application of the liquid-applied membrane. The
surface should be of sufficiently rough texture to provide a mechanical bond for the membrane but not so rough as to preclude
achieving continuity of the membrane of the specified thickness across the surface. A typical manufacturer’s recommendation is
a steel-troweled finish, followed by a fine hair broom.
6.7.1 Concrete surfaces shall be free of laitance, loose aggregate, sharp projections, grease, oil, dirt, curing compounds, or other
contaminants that could affect the complete bonding of the liquid-applied membrane to the concrete surface. For preparation and
acceptance of concrete surfaces, refer to Guide D5295. Application shall not proceed until all protrusions and projections through
the structural slab are in place, or sleeves placed through the slab, and provision has been made to secure their watertightness.
Concrete surfaces shall be visibly dry and pass any additional dryness tests recommended by the liquid-applied membrane
manufacturer prior to application.
6.8 Curing—Curing of the structural slab is necessary to provide a sound concrete surface and to obtain the quality of concrete
required. The concrete should be cured a minimum of 7 days and aged a minimum of 28 days including curing time, before
application of the liquid-applied membrane. Curing is accomplished chemically with moisture and should not be construed as
drying.
6.8.1 Moist Curing—Moist curing is achieved by keeping the surfaces continuously wet by covering them with burlap saturated
with water and kept wet by spraying or hosing. The covering material should be placed to provide complete surface coverage with
joints lapped a minimum of 75 mm (3 in.).[3 in.].
6.8.2 Sheet Curing—Sheet curing is accomplished with a sheet vapor retarder that
...