ASTM D7492/D7492M-11
(Guide)Standard Guide for Use of Drainage System Media with Waterproofing Systems
Standard Guide for Use of Drainage System Media with Waterproofing Systems
SIGNIFICANCE AND USE
This guide provides information and guidelines for the selection and installation of drainage systems media that are in conjunction with waterproofing systems. This guide is intended to be used in conjunction with Guides C898, C981, C1471, D5898, and D6622 and to provide guidelines for the total waterproofing and drainage system.
SCOPE
1.1 This guide makes recommendations for the selection and application of prefabricated drainage media used in conjunction with waterproofing systems on horizontal and vertical surfaces. Drainage media considered include rigid and semi-rigid insulation boards and rigid materials including plastics. The scope of this guide does not cover other drainage media including gravel and filter fabric systems that can be constructed. The scope of this guide does not cover drainage materials or drainage system designs used for vegetative roof systems. Vegetative roof systems require specialized designs.
1.2 The committee with jurisdiction over this standard is not aware of any other comparable standards published by other organizations.
1.3 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.
1.4 This standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation:D7492/D7492M −11
StandardGuide for
Use of Drainage System Media with Waterproofing Systems
This standard is issued under the fixed designation D7492/D7492M; 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 C981Guide for Design of Built-Up Bituminous Membrane
Waterproofing Systems for Building Decks
1.1 This guide makes recommendations for the selection
C1471Guide for the Use of High Solids Content Cold
and application of prefabricated drainage media used in con-
Liquid-Applied Elastomeric Waterproofing Membrane on
junction with waterproofing systems on horizontal and vertical
Vertical Surfaces
surfaces. Drainage media considered include rigid and semi-
D896Practice for Resistance of Adhesive Bonds to Chemi-
rigid insulation boards and rigid materials including plastics.
cal Reagents
The scope of this guide does not cover other drainage media
D1079Terminology Relating to Roofing and Waterproofing
including gravel and filter fabric systems that can be con-
D2434Test Method for Permeability of Granular Soils
structed. The scope of this guide does not cover drainage
(Constant Head) (Withdrawn 2015)
materials or drainage system designs used for vegetative roof
D3273TestMethodforResistancetoGrowthofMoldonthe
systems. Vegetative roof systems require specialized designs.
Surface of Interior Coatings in an Environmental Cham-
1.2 Thecommitteewithjurisdictionoverthisstandardisnot
ber
aware of any other comparable standards published by other
D3385Test Method for Infiltration Rate of Soils in Field
organizations.
Using Double-Ring Infiltrometer
D4511Test Method for Hydraulic Conductivity of Essen-
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in tially Saturated Peat
D4630Test Method for Determining Transmissivity and
each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining Storage Coefficient of Low-Permeability Rocks by In Situ
Measurements Using the Constant Head Injection Test
values from the two systems may result in non-conformance
with the standard. D4716Test Method for Determining the (In-plane) Flow
Rate per Unit Width and Hydraulic Transmissivity of a
1.4 This standard may involve hazardous materials, opera-
Geosynthetic Using a Constant Head
tionsandequipment. This standard does not purport to address
D5898Guide for Details for Adhered Sheet Waterproofing
all of the safety concerns, if any, associated with its use. It is
D6622Guide forApplication of FullyAdhered Hot-Applied
the responsibility of the user of this standard to establish
Reinforced Waterproofing Systems
appropriate safety and health practices and determine the
E154Test Methods for Water Vapor Retarders Used in
applicability of regulatory limitations prior to use.
Contact with Earth Under Concrete Slabs, on Walls, or as
Ground Cover
2. Referenced Documents
2.1 ASTM Standards:
3. Terminology
C165TestMethodforMeasuringCompressivePropertiesof
3.1 Refer to Terminology D1079 for definitions of terms
Thermal Insulations
used in this guide.
C898Guide for Use of High Solids Content, Cold Liquid-
AppliedElastomericWaterproofingMembranewithSepa-
4. Summary of Practice
rate Wearing Course
4.1 Thisguidedescribesamethodtoestimatetheamountof
water a drainage system may need to carry. The guide also
This guide is under the jurisdiction ofASTM Committee D08 on Roofing and
offersdescriptionsofthevariousdrainagesystemsinexistence
Waterproofing and is the direct responsibility of Subcommittee D08.22 on Water-
today along with suggestions on how different building situa-
proofing and Dampproofing Systems.
tionswillrequiredifferentperformancecharacteristicsfromthe
Current edition approved Nov. 15, 2011. Published March 2012. DOI: 10.1520/
drainage medium chosen. Items to be aware of during the
D7492_D7492M-11.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7492/D7492M−11
installation of drainage systems is also covered along with material, must have adequate porosity so as not to restrict
illustrations of typical drainage systems. drainage through the face of the media. In some installations,
particularly those with a high percentage of silt in the backfill,
5. Significance and Use
thefilterporosityshouldbeselectedrelativetothesoilparticle
size distribution to ensure the filter surface will not become
5.1 This guide provides information and guidelines for the
clogged. Where appropriate, a protection board should be
selection and installation of drainage systems media that are in
installed between the waterproofing and drainage media to
conjunctionwithwaterproofingsystems.Thisguideisintended
reduce embedment of drainage media into the waterproofing.
to be used in conjunction with Guides C898, C981, C1471,
D5898, and D6622 and to provide guidelines for the total
6.4 The drainage media selection should include a consid-
waterproofing and drainage system.
eration of the forces that will be placed on it, such as backfill
pressure, gravity loads and shear loads both initially and over
6. General
the expected useful life of the assembly.
6.1 In selecting a drainage medium for use with
6.5 The construction of drainage media should be consid-
waterproofing, consideration should be given to the design of
ered relative to the strength density (carrying capacity) and of
the waterproofing system. In particular orientation of the
the waterproofing membrane. The bearing surface of drainage
system, attachment recommendations, connections to interior
media must place no sharp edges against the waterproofing
and exterior drainage systems and external loads applied to the
membrane, which could puncture, abrade the membrane or
system. Additional considerations include the materials and
imprint itself in the membrane.The filter fabric and its bond to
construction over the drainage medium, installation
the drainage medium core should resist impact, compressive,
recommendations, durability, and penetrations and joints. (See
and shear loads imposed by backfilling and compaction,
Figs. 1-3.) In all designs, the potential slip planes should be
temporary and permanent constructions loads.
considered.
6.6 The drainage media should always be placed next to the
6.2 Compatibility—It is essential that all components and
waterproofing.Thislocationminimizesthehydrostaticheadon
contiguous elements of the waterproofing system are compat-
topofthewaterproofing.Ifinsulationisrequiredtheinsulation
ible and that the design of the system’s waterproofing and
shall be specified to handle the environment that is present
drainage is coordinated to form an integrated waterproofing
outsidethedrainagemediaandwaterproofingmembrane.Ifthe
system.
insulation is porous, the drainage media must allow the porous
6.3 Basic Components—The various types of drainage me-
insulation to drain any water accumulated during construction
dia available are outlined in Section 12 of this guide and all
or during its service on the wall into either the drainage media
consist of one or more of the following basic components.The
or the footing drain tile system.Anon-porous insulation is any
basic components of typical drainage medium are a mounting
insulation with closed cells that prevent water from flowing in
surface that is placed against the waterproofing membrane to
or out, for example extruded polystyrene foam or polystyrene
prevent embedment of the media, a porous core that provides
foam bead boards. A porous insulation is any insulation that
a drainage path, and a filter fabric bonded over the porous core
hasopenchannelsthateasilyallowwatertoenterandleavethe
to prevent clogging of the drainage paths. Fibrous and foam
insulation such as rigid fiberglass boards with a perm rating of
drainagemediaarehomogeneousmaterialsthataresufficiently
4.6 Darcy (k, mm/s) or more (see X1.1.3).
densethattheycanbeplaceddirectlyagainstthewaterproofing
membrane. Other foam boards merely provide periodic
7. Drainage Capacity
grooves creating paths to drain water away from the water-
7.1 General—The drainage capacity is the volume of water
proofed surface. However fibrous and foam media may not
that passes through drainage media in a specified direction
function properly in horizontal or nearly horizontal (<30°)
under a known hydraulic gradient. The two major drainage
orientations. The filter surface, whether fabric or the base
capacities of interest are the in-plane and through-the-face
drainagecapacities.Theorientationofthemediaandanyslope
of the substrate will have a major effect on the drainage
capacity.
7.1.1 Through-the-Face Drainage—Through-the-face
drainage is the flow or seepage of water perpendicular to the
longitudinal axis of the drainage media. When media are
installed in a horizontal orientation, through-the-face drainage
may occur due to failure (that is, cracks) in the material(s)
placed atop the media or due to the normal permeability of the
material(s) such as soil or open joint pavers. When media are
installed in a vertical orientation, though- the-face drainage
capacity should be several times greater than the expected
drainage flow to the media.
7.1.2 In-plane Drainage—In-plane drainage occurs in
FIG. 1Drainage at Lot Line Below-Grade Wall drainage media installed in horizontal orientations, such as
D7492/D7492M−11
NOTE 1—Or slotted drains with ⁄2-in. slots.
FIG. 2Drain in Plaza with Solid Surfacing
have sections devoted to the selection of geotextiles for
filtration and water drainage among other topics.
7.1.4 Long-term Performance—The materials used for
drainage media must be capable of surviving the environment
in which they are placed for at least the life of the waterproof-
ing system. The physical properties of the media that relate to
drainage capacity, such as compressive strength, shear
strength,resistancetobiologicaldeterioration,andfreeze-thaw
resistance must be sustained throughout the service life of the
media.
FIG. 3Drain in Plaza with Paver and Pedestal Surfacing
7.1.5 Another performance issue arises when installing
drainage media on “vegetative roof system” or garden patio
situations. Consideration must be given on how the drainage
plaza decks, parking decks, and below-grade passageways. In
media will either stop root penetration or how the roots from
theseorientations,thehydraulicgradientwillberelativelylow.
large plants and small trees will affect the performance of the
Therefore, the drainage paths or pores in the media should be
drainage media. How this is accomplished along with other
relatively large to ensure the media does not hold water due to
design criteria necessary for a “vegetative roof system” is
surface tension and capillary forces.
beyond the scope of this guide. See Note 1.
7.1.2.1 To determine the drainage capacity needed the
4,5
designer has to be familiar with the climate, terrain, adjacent
NOTE1—Thefootnotedbooksoncivilengineering andotherrelevant
buildingsandstructuresthatcouldredirectrainwaterorrunoff books may be found on web sites such as Amazon.com and Barnesand-
noble.com.
onto the area that has to be drained, if there is soil overburden
onthedrainagemedia,etc.AppendixX1containsmethodsthat
7.1.6 Interfaces To Other Drainage Systems—The selection
could be used to calculate the capacity needed for the drainage
of drainage media must take into consideration the joining of
system. In no way does Appendix X1 contain all the different
the installed media to other adjacent drainage systems that can
methods for calculating the capacity needed by a drainage
be located inside (lagging walls, Fig. 1) and outside of a
system and undoubtedly local methods exist which work quite
building or foundation. For a horizontal orientation, consider-
well in their particular area
ation must be given to adequately connecting the drainage
7.1.3 Resistance to Clogging—Drainage media must resist
media to vertically oriented drainage media. For a vertical
clogging or silting of the media filter or other openings. The
application,considerationmustbegiventotheconnectionwith
selection of the media should be made only after the particle-
the drainage system at the base of the media, usually a
size distribution of the material(s) placed adjacent to the filter
perimeter drain system.
mediaisknown.Ifthefilteropeningsizeislargerelativetothe
8. Physical Properties
majority of adjacent particles, the adjacent particles will pass
though the filter media and may, in time, clog the media. A
8.1 General—Drainage media used in conjunction with a
correctlyselectedfiltermediashouldpermitsomefineparticles
liquidappliedwaterproofingsystemshouldhavecertainphysi-
topassthroughthefaceofthemediabutretainalayeroflarger
cal properties to provide some level of confidence that the
particles at its surface until a filter cake is established.The fine
drainage media will perform as stated throughout its required
particles within the media will eventually be flushed from the
servicelife.Propertiesthatareconsideredinthisguideinclude
media. As for determining which fabric should be used, there
drainage capacity (discussed in Section 7), compressive
are a number of resources that may be used. Several geotextile
strength, flexural strength, puncture resistance edge strength
manufacturershavebrochuresandspecdatasheetsfordifferent
typesoffabricswhichcontaininformationonhowtochosethe
Civil Engineering Handbook,2ndedition,Liew,R.J.V.andChen,W.Feditors,
right geotextile for the given situation. Another fabric may be
August 2002.
needed to handle particular soils or situations with fine laden
Standard Handbook for Civil Engineers, Richards, J. T., Merritt, F. S., and
overburden. Recent civil engineering handbooks (see Note 1) Loftin, M. K., editors, Dec 2003.
D7492/D7492M−11
and embrittlement. ManyASTM standards are available to test prevent deformation of the media and the collapse and closing
thesepropertiesandtheASTMtestswillvarydependingonthe of the drainage paths within the media.
drainage medium being tested. Test Methods D4716 and C165
9.3 Materials used to hold dra
...
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