1、Designation: C 964 07Standard Guide forLock-Strip Gasket Glazing1This standard is issued under the fixed designation C 964; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicate
2、s the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This guide covers the use of lock-strip gaskets incompliance with Specification C 5
3、42 in walls of buildings notover 15 from a vertical plane. The prime performanceconsiderations are weathertightness against air and waterinfiltration, and structural integrity under wind loads. Includedare terminology, design considerations, and fabrication toler-ances when using lock-strip gaskets
4、in glazing applications.1.2 The values stated in SI units are to be regarded as thestandard. The inch-pound units in parentheses are for informa-tion only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of
5、this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 542 Specification for Lock-Strip GasketsC 716 Specification for Installing Lock-Strip Gaskets andInfill Glazing Mat
6、erialsC 864 Specification for Dense Elastomeric CompressionSeal Gaskets, Setting Blocks, and SpacersC 963 Specification for Packaging, Identification, Ship-ment, and Storage of Lock-Strip GasketsC 1036 Specification for Flat GlassE 283 Test Method for Determining Rate of Air LeakageThrough Exterior
7、Windows, Curtain Walls, and DoorsUnder Specified Pressure Differences Across the SpecimenE 330 Test Method for Structural Performance of ExteriorWindows, Doors, Skylights and Curtain Walls by UniformStatic Air Pressure DifferenceE 331 Test Method for Water Penetration of Exterior Win-dows, Skylights
8、, Doors, and Curtain Walls by UniformStatic Air Pressure Difference3. Significance and Use3.1 This guide provides information and guidelines for thedesign of lock-strip gasket glazing systems. For related stan-dards, see Specifications C 542, C 716, and C 963.4. Comparison to Other Standards4.1 The
9、committee with jurisdiction over this standard is notaware of any comparable standards published by other orga-nizations.DESIGN CONSIDERATIONS5. General5.1 Structural integrity and watertightness of a gasket glaz-ing system is dependent on interaction of the several compo-nents involved. These syste
10、ms should be carefully designedand built.6. Components6.1 The major components of lock-strip gasket glazing andpaneling systems are:6.1.1 The supporting frame of metal, concrete, or otherstructural building materials,6.1.2 Lock-strip gasket, serving as an elastomeric mechani-cal seal and as a retain
11、er for panel or glass, and6.1.3 Glass or panel infill.6.1.4 The design of these components and their accessoriesare interrelated and the total system must be compatible.7. Supporting Frames7.1 Supporting frames are made of many materials, ofwhich the more common are aluminum, steel, and concrete.7.1
12、.1 MetalDie marks, ridges, offsets, and scratches inmetal frames in contact with the gasket lips that could causeleakage should be avoided. Metal in contact with any part ofthe gasket should have sharp edges and burrs removed to avoidthe possibility of damage to the gaskets that could result instruc
13、tural failure through tear propagation. Weathering steelframes used in gasket installations should be coated to prevent1This guide is under the jurisdiction ofASTM Committee C24 on Building Sealsand Sealants and is the direct responsibility of Subcommittee C24.73 on Compres-sion Seal and Lock Strip
14、Gaskets.Current edition approved June 1, 2007. Published July 2007. Originally approvedin 1981. Last previous edition approved in 2002 as C 964 88 (2002)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AST
15、MStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.corrosion on the surfaces covered by the gasket to a line notless than 3.2 mm (18 in.) bey
16、ond the lip edge when installed.7.1.2 ConcreteGasket lips in contact with protrusions,crazing, form marks, and offsets on concrete surfaces couldcause leakage and glass breakage and such irregularities shouldbe avoided. Concrete frames for lock-strip gaskets should bejointless and are more suitable
17、when precast, as the tolerancesand smooth surfaces required are too exacting for cast-in-placeconcrete. Special forms and meticulous casting procedures arerequired for optimum performance.7.1.2.1 Corner AnglesCorner angles in the plane of theglass should be held to 62 tolerance to properly receive t
18、hegasket lips. See Fig. 1.7.1.2.2 RegletsIt is essential that the recess in the concretebe accurately cast so as to properly receive the spline of thegasket. This can be accomplished with a plastic reglet that hasa removable weakness membrane as shown in Fig. 1. Theremovable membrane maintains the p
19、roper recess shape andkeeps concrete out of the reglet while being cast. The remov-able membrane can be T-shaped, when desirable, with the stemprojecting from the reglet to provide a more convenient meansof attachment to the formwork of the concrete panel. Aftercasting, the weakness membrane is easi
20、ly removed. Plasticreglets are available with flanges extending beyond the gasketlips, providing smooth contact surfaces. An advantage of theplastic flange is the provision of a smooth rigid surface forcontact with the gasket lip. The plastic flanges are buttedtogether at the corners requiring a joi
21、nt which should beproperly aligned and sealed. The exposed plastic flange shouldbe solidly cast into the concrete without any voids or honey-combing at the leading edge of the flange because water couldenter the interface between the flange and the concrete intowhich it is cast.An advantage of the f
22、langeless reglet is that theexposed joint between the flange and the concrete as well as thecorner butt joints are eliminated and the gasket lips make directcontact with the concrete frame. With this concept it isessential to have a continuous smooth surface free of voids orhoneycombing for the gask
23、et lips to seal against because watercould bypass the gasket lip and enter under it. Also importantis to have a sharp arris at the corners of the concrete frame sothat the corners of the gasket lip can properly contact and sealagainst the concrete. When plastic reglets are used, joints inthem could
24、cause leaks unless sealed. When the gasket lips arein direct contact with the concrete, meticulous casting proce-dures and close surveillance are required to assure a properfinish along the contacting surface.7.1.2.3 Frame LugIt is difficult to achieve watertightnesswith a gasket gripping the lug of
25、 a concrete frame as shown inFig. 2. Casting the lug to the 0.8-mm (6132-in.) tolerancerequired is unrealistic when dealing with concrete. Also,casting it without a tapered draft for ease of form removalresults in complicated form work. A tapered draft providespoor control over gasket lip pressure a
26、nd results in a reductionof pressure when excessive edge clearance permits the gasketlips to slip to the narrower part of the lug. Unless the gasketgripping the lug of a concrete frame has enough mass,insufficient lip pressure against the concrete frame and leakagecould result because of the relativ
27、ely large lug width.7.1.3 JointsIdeally, the best type of frame over which toseat the gasket is one without joints. However, the realities ofconstruction should be recognized and dealt with. Watertight-ness between the lock-strip gasket and frame depends onunbroken pressurized contact. Joints in met
28、al, unless weldedand ground flush and smooth, make this concept difficult toachieve. Members on either side of a butt joint should beinstalled as true to plane as possible. If the design relies uponsealed metal-to-metal joints, the small void between the gasketlip and metal should also be sealed wit
29、h a supplementarysealant. A recommended safeguard is to have a built-indrainage system within the frame. In this way, any waterpenetrating the frame joints or gasket to frame joints will bedirected back to the outdoors. An aid towards minimizing thepossibility of water penetration between the gasket
30、 and frameat static (fixed, nonmoving) metal joints in single openingsmay be seen in Fig. 3. The direction of the joint is horizontalbetween the horizontal and vertical members at the top of theframe, and vertical between the horizontal and vertical mem-bers at the bottom of the frame.7.1.4 Frame-to
31、-Gasket Lips ClearanceBecause lip pres-sure is critical in resisting the passage of water, the design ofthe supporting frame must allow at least 3.2-mm (18-in.)clearance between the installed gasket lip and any projectingA Sharp arris (no radius) requiredB Nominal angle 6 2 toleranceC Smooth surface
32、 requiredD 6.4 mm (14 in.) minimumE Removable weakness membraneF Flange provides smooth surface at lipFIG. 1 Reglet-type Gasket in ConcreteNOTE 1Insufficient mass at A and relative long distance from B tolock-strip minimizes potential for adequate lip pressure at B.FIG. 2 Gasket Mounting on Concrete
33、 LugC964072flanges or fillets. This allows the lips to exert unrestrictedpressure against the frame as shown in Fig. 4. Where the framelug and projecting flange form a fillet, the recommendedclearance should not include the convex portion.8. Gaskets and Accessories8.1 To accommodate the wide variety
34、 of glass and panelthicknesses available as well as allow for mounting to varioustypes of framing members, a wide variety of gasket crosssections are produced by the extrusion manufacturing process.The technique of extruding varies among the manufacturers,and has a limiting factor on the complexity
35、of cross-sectiondesigns produced.8.1.1 Gasket TypesLock-strip gaskets are typically iden-tified by their general cross-section configuration. The mostcommon are H-type and reglet type. Other special and propri-etary interlocking types have been developed as a result ofmodifications to the basic type
36、s, usually because of provisionsfor mounting or mating to special framing members. Gasketsections are generally of two types: the perimeter section andthe muntin section.8.1.1.1 H-TypeThe basic H-type gasket, its installation,and nomenclature are illustrated in Fig. 5. After the gasket isinstalled o
37、ver the frame and the glass or panel infill installed inthe gasket, the lock-strip, which is of higher durometer, isforced into a groove in the gasket. A resultant compressiveforce is transferred to the lips which apply pressure to theframe and glass. Sufficient lip pressure against smooth surfacesc
38、reates an effective weathertight seal. A wide selection ofH-type gaskets are available that accommodate glass, panels,and frame lug thicknesses ranging from 1.6 to 32 mm (116 to114 in.). Gaskets accommodating thicknesses greater than 32mm (114 in.) are also available. Thick panels should not bemount
39、ed on relatively thin lugs as the weight of the glass orpanel cannot be supported properly. The best performance canbe expected where the lug thickness equals or exceeds thethickness of the glass or panel. There are exceptions to thisrecommendation which are dependent upon other factors, suchas ligh
40、tweight panels, extremely small openings, or situationswhere total performance is not required. Acceptable deviationsrequire engineering analysis, consultation with the gasketmanufacturer, and testing.8.1.1.2 Reglet TypeThe reglet-type gasket is a patentedtype whose functional principles and nomencl
41、ature are illus-trated in Fig. 6. Reglet-type gaskets are designed with a splinethat fits into a reglet. The seal against the frame is accom-plished by forcing the spline of the gasket into the reglet so thatthe fins on the side of the spline retain the gasket in the regletand thus hold the sealing
42、lips of the gasket tightly against theframe surface. The seal against the glass or panel is accom-plished by the insertion of the lock-strip as with the H-typegasket. Most reglet-type gaskets are designed to fit into a regletthat is 19 mm (34 in.) deep and 16 mm (58 in.) wide. If thereglet is of les
43、ser depth, the gasket will “bottom-out” and notFIG. 3 Single-opening Metal Frame Joints for IncreasedWatertightnessFIG. 4 Gasket Mounting ClearanceA Hinge H Glass or panelB Lock-strip I BiteC Lock-strip cavity J Edge clearanceD Lip (sealing edge) K Frame-to-glass dimensionE Channel recess L Frame lu
44、gF Flange M FrameGWebFIG. 5 Basic H-Type Gasket, its Functional Principles andNomenclatureA Hinge H Glass or panelB Lock-strip I BiteC Lock-strip cavity J Edge clearanceD Lip (sealing edge) K Frame-to-glass dimensionE Channel recess L SplineF Flange M RegletGWebFIG. 6 Reglet-type Gasket, its Functio
45、nal Principles andNomenclatureC964073provide a proper installation. If the reglet is too wide, thegasket will not be held in place properly and thereby providedifficult glass or panel installation. If the reglet is too narrow,the gasket will be difficult to install. Reglet-type gaskets areavailable
46、that accommodate glass or panel thicknesses from 1.6through 32 mm (116 through 114 in.). There is an importantbasic difference between the H-type and reglet-type gasketsthat should not be overlooked in field application. The lock-strip of both gaskets causes lip pressure against the frame andglass,
47、but with the reglet-type gasket, lip pressure is alsoaffected by the depth of the gasket spline in the reglet. This iscontrolled by the installer at the site as well as by the geometryof the gasket and reglet. Available are reglet-type gaskets thathave projecting offsets at the upper or lower part o
48、f the spline.These are designed to control the depth at which the spline isinserted into the reglet.8.1.1.3 Special Interlocking and Proprietary TypesIn ad-dition to the basic H-type and reglet-type gaskets, there arevarious special interlocking and proprietary type gaskets.Several of these are illu
49、strated in Fig. 7. The basic principle ofthe interlocking type is to achieve greater roll-off resistance ofthe gasket from the frame by mechanically interlocking thegasket to the frame.8.1.2 Gasket JointsBest sealing performance is achievedwith a continuous gasket having factory-formed injection-molded joints. In the use of discontinuous ladder-type gasketsor stick systems (assembled in the field, using cut lengths),achieving a weathertight seal requires a field application ofAB Horizontal membersCFG Vertical member for lateral supportD Horizontal or ver
