1、Designation: E 1643 98 (Reapproved 2005)Standard Practice forInstallation of Water Vapor Retarders Used in Contact withEarth or Granular Fill Under Concrete Slabs1This standard is issued under the fixed designation E 1643; the number immediately following the designation indicates the year oforigina
2、l adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers procedures for installing flexible,prefabric
3、ated sheet membranes in contact with earth or granu-lar fill used as vapor retarders under concrete slabs.1.2 Conditions subject to frost and either heave or hydro-static pressure, or both, are beyond the scope of this practice.1.3 This standard does not purport to address all of thesafety concerns,
4、 if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 The values stated in inch-pound units are to be regardedas the standard. The values
5、 given in parentheses are forinformation only.2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesD 224 Specification for Smooth-Surfaced Asphalt RollRoofing (Organic Felt)3E 631 Terminology of Building Constructions2.2 Other Standard:4ACI 302.1R Guide for Concrete Fl
6、oor and Slab Construc-tion3. Significance and Use3.1 Vapor retarders provide a method of limiting watervapor transmission upward through concrete slabs on grade,which can adversely affect moisture-impermeable or moisture-sensitive floor finishes.3.2 Adverse impacts include adhesion loss, warping, pe
7、el-ing, and unacceptable appearance of resilient flooring; deterio-ration of adhesives, ripping or separation of seams, air bubblesor efflorescence beneath seamed, continuous flooring; damageto flat electrical cable systems, buckling of carpet and carpettiles, offensive odors, and growth of fungi.4.
8、 Manufacturers Recommendations4.1 Where inconsistencies occur between this practice andthe manufacturers instructions, conform to the manufacturersinstructions for installation of vapor retarder.5. Placement5.1 Level and tamp or roll granular base.5.2 Place vapor retarder sheeting with the longest d
9、imensionparallel with the direction of concrete pour.5.3 Lap vapor retarder over footings or seal to foundationwall, or both, and seal around penetrations such as utilities andcolumns in order to create a monolithic membrane between thesurface of the slab and moisture sources below the slab and atth
10、e slab perimeter (see Figs. 1-3).5.4 Lap joints 6 in. (150 mm), or as instructed by themanufacturer, and seal with the manufacturers recommendedadhesive or pressure sensitive tape, or both.6. Protection6.1 Take precautions to protect vapor retarder from damageduring installation of reinforcing steel
11、 and utilities and duringplacement of concrete.6.2 Use only concrete brick type reinforcing bar supports, orprovide 6 by 6 in. (150 by 150 mm) protective pads of asphaltichardboard or other material recommended by the vapor re-tarder manufacturer to protect the vapor retarder from punc-ture.6.3 Avoi
12、d use of stakes driven through vapor retarder.6.4 Refer to X2.2 and X2.3 for discussion of aggregate forprotection of vapor retarder.7. Repair7.1 Repair vapor retarder damaged during placement ofreinforcing or concrete with vapor barrier material or asinstructed by manufacturer.1This practice is und
13、er the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.21 onServiceability.Current edition approved Dec. 1, 2005. Published December 2005. Originallyapproved in 1994. Last previous edition approved in 1998 as E 1643 98.2For referen
14、ced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from American Concrete Institute (ACI), P.O. Box 90
15、94, FarmingtonHills, MI 48333.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Lap beyond damaged areas a minimum of 6 in. and sealas prescribed for sheet joints.8. Suggested Field Check List8.1 Moisture Entrapment Due to Rainfall
16、 or Ground WaterIntrusionMoisture entrapment can occur with tilt-up con-struction or other construction methods where exterior wallsare erected before the concrete slab and underlying subgrade,base, or sand/small aggregate layer, or combination thereof, areprotected from precipitation. This can be a
17、voided by appropri-ate construction scheduling and sealing of any entry points inuncompleted slabs5(see Fig. 4).8.2 Integrity of Vapor RetarderCheck seams and penetra-tions at columns and utilities to look for discontinuities in thevapor retarder.8.3 Damage and RepairAfter installation of reinforce-
18、ment (if used) but before pouring concrete, check for damage.Do not pour concrete until repairs are made, if required, invapor retarder. This is particularly difficult if covered with sandor granular fill.8.4 Moisture Conditions of SlabFollowing placement ofconcrete and climatization of building, ch
19、eck to see that anyspecified tests for moisture emission have been made and awritten report submitted prior to floor covering or coatinginstallation.5Collins, F. Thomas, Manual of Tilt-Up Construction, Berkeley, Know-HowPublications, 1965, pp 7881.FIG. 1 Concrete Slab on Grade: Optimum Relationship
20、of VaporRetarder ComponentsFIG. 2 Concrete Slab on Grade: Solution for Subgrade SlightlyBelow Exterior GradeFIG. 3 Concrete Slab on Grade: Solution for Subgrade Up toOne Story below Grade with No Hydrostatic Pressure on VaporRetarderFIG. 4 How Moisture Can Be Retained in Base or Cushion,Blotter, or
21、Protection Course During ConstructionE 1643 98 (2005)29. Keywords9.1 concrete slabs; vapor; vapor retarderAPPENDIXES(Nonmandatory Information)X1. PRE-DESIGN CONSIDERATIONSX1.1 ArchitecturalX1.1.1 Planning and Organization of ConstructionDocumentsTo avoid ambiguities, redundancies, conflicts,and omis
22、sions, plan the organization and coordination ofdrawings and specifications so that graphic, dimensional, anddescriptive information on subgrade, granular base, vaporretarder, and protection course, if any, appears in only oneplace. Since the relationship of the subgrade (pad) elevation(usually show
23、n on grading plans) to the rest of the buildingfinish floor elevations and finished site grades is a function ofthe depth of the granular base and protection course, thesedimensions should be shown in only one place. For graphicdepictions and dimensions of the granular base and theprotection course,
24、 the architectural drawings are preferred, butstructural drawings are sometimes used. Specifications forsub-base conditions should be in the grading section. Specifi-cations for base, vapor retarder, and protection course shouldbe in the section on concrete, but there are advocates of aseparate sect
25、ion in Division 7 for the vapor retarder system.Examination and testing of surface conditions should be inappropriate finish sections.X1.1.2 SchedulingDetermine if slab drying will be on thecritical path for schedule occupancy. If so, plan measures toreduce drying times, mitigate moisture, or select
26、 floor finishmaterials not subject to damage by moisture.X1.1.3 GeotechnicalEnsure that the geotechnical surveyincludes comprehensive and reliable information on subsurfacewater table levels and the hydrology of geological strata as wellas historical data on surface flooding and hydrology. Thegeotec
27、hnical study should consider not only the past but alsothe projected change from ongoing or anticipated developmentpatterns. Soils with comparably higher clay contents areparticularly troublesome because the relatively high capillaryaction within the clay allows moisture to rise under the slab.X1.1.
28、4 CivilEnsure that site topographic surveys andgrading plans accurately and comprehensively establish sur-face drainage characteristics for the site and surrounding areas.X1.1.5 Landscape and IrrigationMost traditional geo-technical studies do not take into account the post-constructionchange in gro
29、und moisture conditions due to introducedplanting and irrigation which is a major problem. For example,in California coastal areas, the average annual rainfall is about18 in. (457 mm). Turf irrigation amounting to 1.3 in. (33 mm)of water per week over the normal 7-month dry season willincrease this
30、to nearly 60 in. (1524 mm) with almost no runoff.It is not enough to assume that irrigation will simply duplicatenatural conditions encountered during the wet season. Thelandscape architect, geotechnical engineer, and civil engineershould closely coordinate design recommendations to avoidmoisture pr
31、oblems introduced or exacerbated by landscapeplanting and irrigation. Once a project is completed, effectiveirrigation management is instrumental not only in waterconservation, but also in avoiding potential building-relatedmoisture problems.X2. DESIGN PHASE CONSIDERATIONSX2.1 Subgrade Design and Sp
32、ecificationX2.1.1 Specify preparation and configuration of sub-basematerial as directed by the geotechnical engineer. Designsub-grade topography and drainage to ensure positive relief ofhydrostatic pressure. Incorporate design of mechanical drain-age system if gravity outflow is not possible, or des
33、ignsub-grade waterproofing to resist expected hydrostatic pres-sures.X2.1.2 The grading specifications must require the contrac-tor to keep any below grade excavations free of water. It isimportant to avoid potential reservoirs of moisture that migrateupward through slabs, but it is also important t
34、o preventstructural degradation of soil bearing strength and to avoidswelling and subsequent shrinkage in soils containing exces-sive silt/clay with expansive characteristics. If any subgrademoisture-induced swelling is anticipated, the construction se-quence should be planned so that it occurs prio
35、r to slabconstruction rather than after.X2.1.3 ACI 302.1R-89 warns that the subgrade must bewell drained and of adequate and uniform load-bearing nature.The “in-place density” of the subgrade soils should be at leastthe minimum required in the specifications. The bottom of anundrained granular base
36、course must not be lower than theadjacent finished grade; otherwise, the base course becomes areservoir for water.X2.1.4 Details of site preparation are given by ACI Com-mittee 330 and the Building Research Advisory Board. Whenexpansive soils are encountered, the recommendations of asoils engineer s
37、hould be followed.X2.1.5 The subgrade must be free of frost before concreteplacing begins. If the temperature inside a building in whichconcrete is to be placed is below freezing it must be raised andE 1643 98 (2005)3maintained above 50F (10C) long enough to remove all frostfrom the subgrade. The su
38、bgrade should be moist at the time ofconcreting. If necessary it should be dampened with water inadvance of concreting, but there must be no free water standingon the subgrade, nor should there be any muddy or soft spotswhen the concrete is placed (see ACI 301.2 R89, 3.1).X2.2 Open Drain Rock Base/C
39、apillary Break Design andSpecification:X2.2.1 A base using a minimum of 3 in. (76 mm) of clean,compacted, crushed rock provides adequate bearing strengthwhile at the same time incorporates sufficient air pockets toreduce the potential of ground water migrating upward throughcapillary action. While a
40、 vapor retarder used in conjunctionwith the base may obviate the need for capillary break, thebreak provides a margin of safety in case of punctures and lapseam failures.X2.2.2 To be an effective capillary break, the base should beopen (mostly single) graded, clean coarse rock of34 in. (19mm) maximu
41、m size.X2.2.3 Both crushed and river run rock are used, but one orthe other may not be readily available in certain areas. Crushedrock is much more likely to cause puncture damage to thevapor retarder but is more easily compactable. If crushed rockis used, special attention must be given to selectin
42、g andprotecting the vapor retarder. A12-in. (approximately 13-mm)layer of fine grade, compactible fill may be rolled or compactedover the base to protect against crushed rock base.X2.3 Cushions, Blotters, and Protection Courses:X2.3.1 BackgroundThe use of a cushion, blotter, or pro-tection course ha
43、s often been considered an integral part of thevapor retarder installation because one of its perceived func-tions is to protect the vapor retarder from damage.Aconsensusof vapor retarder product producers is that the protection roleis either unnecessary or overrated and should not be acomponent of
44、an application standard practice for vaporretarders. The principal role of the cushion, blotter, or protec-tion course, according to its proponents, is its function in theplacement, finishing, and curing of concrete. Its use, if any,should be related to the concrete mix design and curingspecificatio
45、ns, not the use of a vapor retarder. Nevertheless, thefollowing considerations are provided to guide the specifier.X2.3.2 Arguments in Favor of Cushions, Blotters, andProtection Courses:X2.3.2.1 Blotter TheoryAcommon practice in many partsof the United States is to place a layer of sand or granular
46、fillon top of the vapor retarder prior to the placement of concrete.The theory is that the fill serves as a blotter to help equalizemoisture content and reduce plastic shrinkage cracking. In the1980 version of ACI 302.1, the fill is described as “sand.” InACI 302.1R-96, Guide for Concrete Floor and
47、Slab Construc-tion (4.1.4 and 4.1.5), and is no longer recommended. Insteada “fine graded” material is described as follows:X2.3.2.2 Base MaterialUse of the proper material isessential in order to achieve the tolerances suggested in Section4.1.3 of ACI 302.1R-96. The base material should be compact-
48、ible, easy-to-trim, granular fill that will remain stable andsupport construction traffic. The tire of a loaded concrete truckmixer should not penetrate the surface more than12 in. (13mm) when driven across the base. The use of so-called cushionsand or clean sand with uniform particle size, such as
49、concretesand meeting Specification C33 will not be adequate. Thistype of sand will be difficult, if not impossible, to compact andmaintain until concrete placement is complete. A clean, fine-graded material with at least 10 to 30 % of particles passing aNo. 100 (150 m) sieve but not contaminated with clay, silt, ororganic material is recommended. Manufactured sand from arock-crushing operation works well; the jagged slivers tend tointerlock and stabilize the material when compacted. It isimportant that the material have a uniform distribution ofparticle sizes
