ASTM C898/C898M-09(2024)

Standard Guide for Use of High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane with Separate Wearing Course

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 C1471/C1471M for application on below grade walls and vertical surfaces.
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 C836/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 nonconformance 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, health, and environmental 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.

General Information

• Status: Published
• Publication Date: 31-Mar-2024
• ICS: 83.060 - Rubber
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: D08 - Roofing and Waterproofing
• Drafting Committee: D08.22 - Waterproofing and Dampproofing Systems

Relations

• Replaces: ASTM C898/C898M-09(2017) - Standard Guide for Use of High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane with Separate Wearing Course
• Effective Date: 01-Apr-2024
• Referred By: ASTM C836/C836M-18(2022) - Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course
• Effective Date: 01-Apr-2024
• Referred By: ASTM E2266-22 - Standard Guide for Design and Construction of Low-Rise Frame Building Wall Systems to Resist Water Intrusion
• Effective Date: 01-Apr-2024
• Referred By: ASTM D8463/D8463M-23 - Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric, Silyl-Terminated Polymer Based Waterproofing Membrane for Use with Separate Wearing Course
• Effective Date: 01-Apr-2024
• Referred By: ASTM D7492/D7492M-16a(2024) - Standard Guide for Use of Drainage System Media with Waterproofing Systems
• Effective Date: 01-Apr-2024
• Referred By: ASTM C1471/C1471M-22 - Standard Guide for the Use of High Solids Content Cold Liquid-Applied Elastomeric Waterproofing Membrane on Vertical Surfaces
• Effective Date: 01-Apr-2024

Overview

ASTM C898/C898M-09(2024) is a standard guide developed by ASTM International, providing guidance for the use of high solids content, cold liquid-applied elastomeric waterproofing membranes. These membranes are specifically designed for building decks constructed over occupied spaces and are covered by a separate, protective wearing course. The standard addresses waterproofing systems that are subject to hydrostatic pressure, emphasizing both the protection of the membrane and the importance of long-term watertightness.

This guide helps professionals understand key considerations and best practices when specifying, designing, and installing cold liquid-applied waterproofing membranes. Importantly, it is not a specification for installation itself but a valuable reference for design and consultation.

Key Topics

• Waterproofing System Components

  • Structural building deck or substrate, typically reinforced cast-in-place concrete.
  • High solids content, cold liquid-applied elastomeric membrane in accordance with ASTM C836/C836M.
  • Protective wearing course and drainage features.

• Substrate Requirements

  • Concrete strength, density, moisture content, and finish are critical to long-term membrane performance.
  • Proper curing and dryness of the substrate are essential before membrane application.
  • Only certain lightweight aggregates are suitable due to moisture retention and structural requirements.

• Membrane Application Considerations

  • Adherence to the substrate is crucial for leak detection and overall system effectiveness.
  • Proper treatment and detailing at terminal conditions (walls, drains, penetrations, expansion joints) to prevent water ingress.
  • Application should be under dry, frost-free conditions at recommended substrate and ambient temperatures.
  • Primer usage, material compatibility, and sequence of installation significantly impact membrane integrity.

• Joints and Expansion Treatments

  • Definitions and recommended treatments for reinforced, nonreinforced, and expansion joints.
  • Use of elastomeric sealants and preformed sheets to manage movement and maintain watertightness.
  • Special attention to detail at expansion joints using positive seal or water shed concepts.

• Drainage Systems

  • Importance of adequate slope and multilevel drainage to prevent standing water and reduce hydrostatic pressure.
  • Open-joint and closed-joint system guidance for various deck constructions.
  • Integration of drainage at membrane and wearing course levels is essential to system performance.

Applications

This guide is essential for:

• Architects, Engineers, and Designers: To inform the specification of high-performance waterproofing solutions for plaza decks, parking structures, and terraces over occupied spaces.
• Contractors and Installers: To consult on the sequence of work, handling of substrates, treatment of joints and penetrations, and ensuring overall water resistance.
• Building Owners and Facility Managers: To understand system requirements for long-term durability, maintenance, and repair considerations.

Typical applications include:

• Plazas, courtyards, and green roofs built over habitable or usable spaces.
• Podium slabs, parking structures, and bridge decks requiring robust waterproofing under separate surface finishes.
• Occasions where hydrostatic pressure is present, demanding high-performance liquid-applied systems.

Related Standards

For comprehensive waterproofing system design, installation, and material selection, reference these ASTM and ACI standards:

• ASTM C836/C836M: High solids content, cold liquid-applied elastomeric waterproofing membrane specification.
• ASTM C920: Elastomeric joint sealants specification.
• ASTM C1471/C1471M: Application of high solids content cold liquid-applied membranes on below-grade walls and vertical surfaces.
• ASTM D5295/D5295M: Preparation of concrete surfaces for membrane waterproofing systems.
• ASTM D1056: Flexible cellular materials for joint fillers.
• ASTM D6506/D6506M: Asphalt-based protection board for below grade waterproofing.
• ACI 301: Specifications for structural concrete in building construction.

Summary

ASTM C898/C898M-09(2024) provides essential guidance for selecting and applying high solids content, cold liquid-applied elastomeric waterproofing membranes in demanding construction environments. By following the recommendations in this standard, professionals can enhance the longevity and performance of waterproofed decks, ensuring both functionality and safety in occupied spaces below. Incorporating referenced standards and best practices leads to optimized waterproofing systems suitable for contemporary building needs.

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: C898/C898M − 09 (Reapproved 2024)
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 nonconformance
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 Asphalt 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/D5295M Guide for Preparation of Concrete Surfaces
ization established in the Decision on Principles for the
for Adhered (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/D6134M Specification for Vulcanized Rubber Sheets
Used in Waterproofing Systems
2. Referenced Documents
D6451/D6451M Guide for Application of Asphalt-Based
2.1 ASTM Standards:
Protection Board
C33/C33M Specification for Concrete Aggregates
D6506/D6506M Specification for Asphalt Based Protection
C578 Specification for Rigid, Cellular Polystyrene Thermal
Board for Below-Grade Waterproofing
Insulation
E1907 Guide to Methods of Evaluating Moisture Conditions
C717 Terminology of Building Seals and Sealants
of Concrete Floors to Receive Resilient Floor Coverings
(Withdrawn 2008)
This guide is under the jurisdiction of ASTM Committee D08 on Roofing and 4
2.2 American Concrete Institute Standard:
Waterproofing and is the direct responsibility of Subcommittee D08.22 on Water-
ACI 301 Specifications for Structural Concrete for Buildings
proofing and Dampproofing Systems.
Current edition approved April 1, 2024. Published April 2024. Originally
approved in 1978. Last previous edition approved in 2017 as C898/C898M – 09
(2017). DOI: 10.1520/C0898_C0898M-09R24.
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 [e-mail]. 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 (2024)
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
Terminology C717. 3.2.11 troweled finish—a concrete finish provided by
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 (2024)
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.
6.7 Finish—The structural slab should have a finish that
6.3 Density and Moisture Content—Density of concrete and
moisture content when cured are interrelated and can affect facilitates proper application of the liquid-applied membrane.
The surface should be of sufficiently rough texture to provide
adhesion of the membrane to the substrate with an excessively
high moisture content; moisture may condense at the mem- a mechanical bond for the membrane, but not so rough as to
preclude achieving continuity of the membrane of the specified
brane and concrete interface and cause membrane delamina-
tion. This is particularly so if the top surface is cooler than the thickness across the surface. A typical manufacturer’s recom-
mendation is a steel-troweled finish, followed by a fine hair
concrete below. Lower moisture contents are achieved with the
use of hard, dense stone aggregate. This type of coarse broom.
6.7.1 Concrete surfaces shall be free of laitance, loose
aggregate will generally provide structural concrete with a
moisture content from 3 to 5 % when cured. Lightweight aggregate, sharp projections, grease, oil, dirt, curing
compounds, or other contaminants that could affect the com-
aggregate, such as expanded shale, will generally provide
lightweight structural concrete with a moisture content from 5 plete bonding of the liquid-applied membrane to the concrete
surface. For preparation and acceptance of concrete surfaces,
to 20 % when cured. Lightweight insulating concrete made
with a weaker expanded aggregate, such as perlite, has a refer to Guide D5295/D5295M. Application shall not proceed
until all protrusions and projections through the structural slab
relatively low compressive strength and can contain over 20 %
moisture when cured. The concrete used for the substrate are in place, or sleeves placed through the slab, and provision
3 3
has been made to secure their watertightness. Concrete sur-
should have a minimum density of 1762 kg/m [110 lb/ft ] and
have a maximum moisture content of 8 % when cured. From faces shall be visibly dry and pass any additional dryness tests
recommended by the liquid-applied membrane manufacturer
this it can be seen that only certain lightweight aggregates can
be considered for use and no lightweight insulating aggregates prior to application.
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
concrete required. The concrete should be cured a minimum of
Modifiers—Admixtures, additives, and modifiers serve many
seven days and aged a minimum of 28 days, including curing
functions in mixing, forming, and curing concrete, such as to
time, before application of the liquid-applied membrane. Cur-
retard or accelerate the cure rate; reduce the water content
ing is accomplished chemically with moisture and should not
required; entrain air; increase strength; create or improve the
be construed as drying.
ability of the concrete to bond to existing, cured concrete;
permit thin topping overlayers; and improve workability. Some 6.8.1 Moist Curing—Moist curing is achieved by keeping
the surfaces continuously wet by covering them with burlap
admixtures and modifiers (particularly polymeric, latex, or
other organic chemical based materials) may coat the concrete saturated with water and kept wet by spraying or hosing. The
covering material should be placed to provide complete surface
particles and reduce the ability of the waterproofing membrane
to bond to the concrete. The membrane manufacturer should be coverage with joints lapped a minimum of 75 mm [3 in.].
consulted if the concrete used for the deck will contain any
6.8.2 Sheet Curing—Sheet curing is accomplished with a
admixtures, additives, or modifiers in order to determine the sheet vapor retarder that reduces the loss of water from the
compatibility 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
are referred to as reinforced joints, nonreinforced joints, and
6.6 Slope for Drainage—Drainage at the membrane level is
important. When the waterproofing membrane is placed di- expansion joints.
rectly on the concrete slab, a monolithic concrete substrate 6.10.1 Reinforced Joints—Reinforced joints consist of hair-
slope of a minimum 2 % [ ⁄4 in./ft] should be maintained. Slope line cracks, cold joints, construction joints, isolation joints, and
is best achieved with a monolithic structural slab and not with control joints held together with steel reinforcing bars or wire
a separate concrete fill layer. The fill presents the potential of fabric. These are considered static joints with little or no
C898/C898M − 09 (2024)
anticipated movement because the slab reinforcement is con- 7.2.4 Safety—Where hazardous materials are involved, rigid
tinuous across the joint. adherence to the special precautions of the manufacturer as
modified by local, state, and federal authorities shall be
6.10.2 Nonreinforced Joints—Nonreinforced joints consist
followed.
of butted construction joints and isolation joints not held
together with steel reinforcing bars or wire fabric. These joints
7.3 Placement Protection—The membrane should be ap-
are generally considered by the designer of the structural
plied under dry, frost-free conditions on the surface as well as
system as nonmoving or static joints. However, they should be
throughout the depth of the concrete slab. Excessive moisture
considered as capable of having some movement, the magni-
in the substrate (see 6.3) or moisture on the surface as from
tude of which is difficult to predict.
frost or rain will result in a defective membrane with such
6.10.3 Expansion Joints—Expansion joints are designed to
deficiencies as an improper cure with formation of excessive
accommodate a predetermined amount of movement. Such
gas pockets and little or no adhesion to the substrate. Should
movement could be due to thermal change, shrinkage, creep,
rain or snow interrupt the application after at least one coat of
deflection, or other factors and combinations of factors. In the
material has been applied, the instructions of the membrane
detailing of expansion joints to achieve watertightness, the
manufacturer should be followed pertaining to any necessary
amount of movement anticipated should be carefully deter-
treatment of the cured, already applied material prior to
mined using a reasonable factor of safety. The opening size and
continuation.
configuration should then be related to the capability of the
7.3.1 The applicator of the liquid-applied membrane shall
joint seal materials to accommodate the anticipated movement.
inspect the substrate including all penetrations and terminal
Expansion joints are best located at the high points of a
conditions to determine the suitability for application of the
contoured slab to permit water to flow away from the joint.
liquid-applied membrane waterproofing. Installation shall not
proceed until corrections have been made of any adverse
7. Membrane
conditions. Any unforeseen but unacceptable conditions shall
be brought to the attention of all parties concerned for
7.1 Adherence to Substrate—A liquid-applied waterproofing
resolution prior to proceeding.
membrane has the capability of adhering to the structural slab
7.3.2 Waterproofing work shall not commence at ambient
and should be applied to take optimum advantage of this
temperatures below 5 °C [40 °F] or when there is any threat of
inherent characteristic. The detection of leakage in a building
inclement weather (rain or snow) unless precautions are taken
deck waterproofing system that is covered over with a separate
to eliminate frost from the substrate or prevent its formation
wearing course could be a significant problem when the
during the application.
waterproofing membrane is not bonded to the structural slab or
when additional layers of material separate the membrane from
7.4 Priming—Primers, when required or recommended by
the structural slab. Water penetrating an unbonded membrane
the manufacturer for optimum performance of the liquid-
could migrate laterally under the membrane until reaching a
applied membrane, shall be as recommended and supplied by
crack or defect in the structural slab and then leak through to
the manufacturer of the liquid-applied membrane.
the space below. Leakage through the slab, therefore, would
7.5 Membrane—The liquid-applied membrane shall be in
not necessarily indicate the location of the water entry in the
conformance with Specification C836/C836M.
membrane above. That point could be at a considerable
distance away, and the costly removal of large areas of the 7.5.1 The liquid-applied membrane shall be applied directly
wearing course might be required before it is located. to the slab in order to obtain 1.5 6 0.1 mm [60 6 5 mils] dry
film thickness. The 1.5 mm is in addition to any previously
7.2 Certification, Marking, Shipping, Preservation, and
applied material. Application shall be made by means of
Safety:
trowel, squeegee, roller, brush, spray apparatus, or other
7.2.1 Certification—Testing laboratory certification from a
method acceptable to the membrane manufacturer. Wet film
laboratory acceptable to the purchaser and containing complete 2 2
thickness shall be checked every 9 m [100 ft ] by the appli-
test results shall be made available before delivery of materials
cator. Where possible, the surface to be coated shall be marked
to the project site, attesting that the materials conform to the
off in even units to facilitate proper coverage. At the expansion
specification requirements. Such certification shall be current
joints and terminations, the membrane shall be carried over the
with results obtained from tests performed no earlier than one
preformed elastomeric sheet in a uniform 2.5 mm [100 mil] dry
year from the award of contract.
thickness to provide a monolithic coating. When work has
7.2.2 Marking and Shipping—The liquid-applied membrane
stopped long enough for the membrane to cure, the first
materials shall be delivered undamaged to the project site in
operation of the next application shall be to wipe the previously
original, sealed containers, clearly identified as to contents, the
applied material with a proper solvent to remove the dirt and
manufacturer’s name, date of manufacture, shelf life, precau-
dust that has accumulated, a condition that could inhibit
tions on flammability and toxicity, and shall include instruc-
adhesion of the overlapping membrane coat. Solvent should be
tions as to application procedures.
as recommended by the membrane manufacturer. Dry film
7.2.3 Preservation—Materials shall be stored and protected thickness is relative and depends upon the solids content of the
from damage and weather in accordance with the manufactur- specific membrane selected. To obtain the required wet film
er’s instructions and shall be used within the period noted as thickness to provide 1.5 mm dry film thickness, divide the
their shelf life. 1.5 mm thickness by the volume solids content of the coating
C898/C898M − 09 (2024)
to obtain the wet film thickness required. Rule of thumb is 15 7.6.3 Termination at Penetrations—Penetrations or protru-
2 2
L/9 m [4 gal/100 ft ]. sions through the slab by such items as conduits and service
pipes create critical problems and should be avoided wherever
7.6 Terminal Conditions—Four locations where a liquid-
possible. For protection at such critical locations, pipe sleeves
applied membrane is normally terminated or interrupted are on
should be cast into the structural slab against which the
walls, at drains, at penetrations, and at expansion joints having
membrane can be terminated. Core drilling to provide openings
relatively large movement. The important consideration at
for penetrations is not recommended.
terminal conditions is to prevent water from penetrating into
7.6.3.1 Protrusions or projections through the structural
the substrate or behind the membrane at its edge.
slab, such as vents and service pipes, shall be treated before
7.6.1 Termination on Walls—When the membrane is turned
application of the liquid-applied membrane. An application of
up on a wall, it is preferable to terminate it above the wearing
2.5 mm [100 mils] of liquid-applied membrane shall be made
surface to eliminate the possibility of ponded surface water
over a sealant joint and up the pipe sleeve and extended
penetrating the wall above the membrane and running down
150 mm [6 in.] onto the structural slab (see Fig. 7).
behind it into the building. The minimum safe height of such a
termination is dictated by the opportunity for conditions such
7.7 Treatment at Joints—Joints in the structural slab should
as ponding and drifted snow presented by the building’s
be treated as follows, depending upon whether they are
geometry and environment. A liquid-applied membrane, be-
reinforced joints, nonreinforced joints, or expansion joints:
cause of its inherent adhesive properties, may be terminated
7.7.1 All preparation of surfaces, cracks or joints, and
flush on the wall without the use of a reglet. However, the use
termination points, including priming if required, shall be
of a reglet in a concrete wall has the advantage of providing
completed before the application of the monolithic liquid-
greater depth protection at the terminal. The reglet should be a
applied membrane. If required, priming shall be done not more
minimum of 6.3 mm [ ⁄4 in.] deep and 6.3 mm wide. Termi-
than 24 h before the membrane is placed. Reinforced joints or
nation on a masonry wall will require counterflashing. (See
cracks in the structural slab may be pretreated by cleaning and
Figs. 2-4.)
coating with a 1.5 mm [60 mil] dry film application of
7.6.1.1 Where the deck-to-wall intersection is a monolithic
liquid-applied membrane extending 76 mm [3 in.] from each
concrete pour or of reinforced concrete joint construction, (a)
side of the joint or crack (see Fig. 8).
preparation coat(s) totaling 2.5 mm [100 mils] of liquid-
7.7.2 Treatment at Reinforced Joints—Fig. 8 indicates one
applied membrane shall be applied that extends 150 mm [6 in.]
recommended treatment of reinforced concrete joints in the
onto the horizontal deck and up the vertical wall to the
structural slab. The designer should realize that the elongation
termination height (see Fig. 5). At the applicator’s option, a
capacity of this type of detail is quite limited and implicitly
cant strip formed with the liquid-applied membrane having a
relies on the membrane’s crack-bridging ability to withstand
45° beveled face of 13 mm [ ⁄2 in.] may be applied (see Fig. 5).
the strains imposed by the opening of cracks and reinforced
7.6.2 Termination at Drains—Drains should be designed
joints. An alternative approach that may be considered is to
with a wide flange or base as an integral part. The drain base
prevent the membrane from adhering to the substrate for a
should be set flush with the structural slab. The wide flange
finite width centered on the joint or crack by means of a
provides a termination point for the liquid-applied membrane
properly designed compatible bond-breaker tape.
without endangering the function of the membrane or the drain.
7.7.3 Treatment at Nonreinforced Joints—Nonreinforced
7.6.2.1 Drain flanges shall have been set flush with the
joints that are in reality nonmoving could be treated in the same
surface of the structural slab. The liquid-applied membrane
manner as reinforced joints. However, since the joints are not
shall be applied 1.5 mm [60 mils] thick over the drain flange or
held together with reinforcing steel, some movement, however
collar with care not to plug any drainage or weep holes. The
slight, should be anticipated and provided for since the
doubled membrane shall extend 150 mm [6 in.] beyond the
liquid-applied membrane has limited ability to take movement.
flange onto the structural slab (see Fig. 6).
Nonreinforced joints could open due to such factors as
shrinkage, creep, and thermal contraction. Fig. 9 shows a
nonreinforced butted joint that is capable of expanding 3.2 mm
[ ⁄8 in.], the minimum that should be provided for when using
a sealant capable of 625 % movement. The minimum sealant
width should be correspondingly wider with a sealant having
lesser movement capability. If the designer of the structural
system feels that greater movement than 3.2 mm [ ⁄8 in.] could
occur in such joints, they should be treated as expansion joints.
7.7.3.1 Sealant—Sealant for use in nonreinforced butted
joints in a structural concrete slab shall be an elastomeric
sealant compatible with the liquid-applied membrane conform-
ing to Specification C920. The compatibility of the liquid-
applied membrane and the sealant shall be determined by the
manufacturer of the liquid-applied membrane.
7.7.3.2 Sealant Primer—A primer when required or recom-
FIG. 2 Terminal Condition Above Finish Grade on Concrete Wall
(see 7.6.1) mended by the manufacturer of the sealant for optimum
C898/C898M − 09 (2024)
FIG. 3 Terminal Conditions on Concrete Wall Below Finish Wearing Surface at Grade (see 7.6.1)
FIG. 4 Terminal Condition with Masonry Above Finish Wearing Surface at Grade (see 7.6.1)
adhesion of the sealant to the joint interface shall be as 7.7.4 Treatment at Expansion Joints—There are basically
recommended by or supplied by the sealant manufacturer and two concepts that could be considered in the detailing of
shall be compatible with the liquid-applied membrane. The expansion
...