Transcription

High Performance BuildingDow Performance SiliconesDow AmericasTechnical Manual

Dow Americas Technical ManualTable of ContentsIntroduction . 3Technical Information Center . 3Product Offering . 4Structural Glazing Sealants . 4Weatherproofing Sealants. 4Primers. 6Building Sealant Recommendations and Surface Preparation Guide for Weatherseal Applications . 7Silicone Structural Glazing. 10Introduction . 10Structural Joint Design . 10Structural Bite . 11Deadload . 12Glueline Thickness . 13Structural Silicone Used in Shear . 15Structural Silicone Used in Seismic Applications . 15Splice Joints in Curtainwalls . 16Structural Glazing Guidelines . 18Substrate Suitability. 18Back-Painted Glass . 20Project Review Services . 21Product Recommendations . 21Classification of Silicone Structural Glazing . 23Application Methods for Structural Glazing Systems . 24Surface Preparation and Sealant Application . 27Replacement and Remedial Glazing. 31Quality Assurance – Structural Applications . 32Alternate Quality Control Tests. 44Documentation – Quality Assurance and Warranty . 45Weatherproofing . 53Introduction . 53Joint Movement . 53Joint Types. 55Joint Design . 56Moving Joint Considerations . 56Joint Movement in Shear . 57Movement During Cure . 58Backer Materials . 59Hydrophobic Effects . 59EIFS Considerations for Design and Specification . 60Weatherseal Design Examples . 61Weatherproofing Joints: Surface Preparation and Sealant Application. 68Removal and Replacement of Existing Weatherseals . 72Sealant Interaction Considerations . 75Quality Assurance – General . 75Documentation – Quality Assurance and Warranty . 79Appendix A: Cure Inhibition of DOWSIL 790 Silicone Building Sealant . 84Appendix B: Use of DOWSIL Sealants with Weathered Lock-Strip Gasket Systems . 86Appendix C: Winter/Summer Considerations . 872

Dow Americas Technical ManualIntroductionThis manual is intended to give guidance on proper application procedures and assist in the developmentof a quality assurance program for the application of DOWSIL silicone sealants for structural andweathersealing systems.As construction projects vary in many aspects, such as design, customer requirements and environment,this manual cannot be considered a comprehensive quality assurance program for all situations.Any review, recommendation or statement made on behalf of Dow relating to an engineering design,architectural drawing, product formulation, end-use specification or similar document is limited to theknowledge of product properties as determined by laboratory testing of material produced by Dow. Anycomments or suggestions relating to any subject other than such product properties are offered only tocall to the attention of the engineer, architect, formulator, end-user or other person considerations thatmay be relevant in his/her independent evaluation and determination of the appropriateness of suchdesign, drawing, specifications, document or formula.Dow assumes no responsibility for the comments or suggestions relative to subjects other than suchproduct properties and expressly disclaims any warranty or responsibilities for them.SITE ADHESION TESTING MUST BE VERIFIED ACCORDING TO THE CRITERIA ONPAGE 75 TO CONFIRM PROPER SURFACE PREPARATION PROCEDURES HAVE BEENFOLLOWED.Technical Information CenterThis service center provides a process and the resources to manage customers’ product and technicalinformation inquiries. This includes (but is not limited to): Environmental Health and Safetyinformation, product recommendations, product troubleshooting, competitive cross-references, andapplication assistance. Inquiries are received via telephone, e-mail, contact us forms, fax and Live Help.Telephone: 1 800 346 9882 (press #1 on menu)E-mail:[email protected]

Product OfferingStructural Glazing SealantsDow has a full line of high-performance silicone structural sealants. Following is a brief summary ofeach DOWSIL brand product offered for structural glazing applications. These sealants should beselected based upon the unique properties that each has for specific applications. Specific productinformation, such as physical properties, application and limitations, can be found in data sheetsavailable at consumer.dow.com/construction.DOWSIL 983 Structural Glazing SealantDOWSIL 983 Structural Glazing Sealant Curing Agent is a two-component, fast-cure, neutral-curingsilicone sealant intended for structural bonding of glass, metal and other building components, as well asweatherseals in curtainwall units. DOWSIL 983 Structural Glazing Sealant cures to a high modulusadhesive sealant with excellent adhesion to a wide range of substrates. Available in black and gray.DOWSIL 995 Silicone Structural SealantDOWSIL 995 Silicone Structural Sealant is a one-part, medium modulus, neutral-curing siliconesealant with superior unprimed adhesion for structural glazing applications. Available in black, grayand white.DOWSIL 795 Silicone Building SealantDOWSIL 795 Silicone Building Sealant is a one-part, medium modulus, neutral-curing siliconesealant for structural glazing and weathersealing. Available in a wide variety of colors.DOWSIL 121 Structural Glazing SealantDOWSIL 121 Structural Glazing Sealant is a two-part, fast-cure, neutral-curing silicone sealantintended for structural bonding without the need of a two-part pump. It is ideal for repairs and/orreplacement of structurally glazed glass and other substrates, for on-site structural glazing and in-shopstructural glazing where the use of a two-part pump is not viable. It is supplied in dual-cartridge kits andit is available in black and gray.Weatherproofing SealantsDow has a full line of high-performance weatherproofing sealants. Following is a brief summary of eachDOWSIL product offered for weatherproofing applications. These sealants should be selected basedupon the unique properties that each has for specific applications. Specific product information, such asphysical properties, application and limitations, can be found in data sheets available atconsumer.dow.com/construction.DOWSIL 795 Silicone Building SealantDOWSIL 795 Silicone Building Sealant is a one-part, medium modulus, neutral-curing siliconesealant for structural glazing and weathersealing. Available in a wide variety of colors.DOWSIL 791 Silicone Weatherproofing SealantDOWSIL 791 Silicone Weatherproofing Sealant is a one-part, medium modulus, neutral-curingsilicone sealant for general weathersealing applications. Available in a wide variety of colors.4

DOWSIL 790 Silicone Building SealantDOWSIL 790 Silicone Building Sealant is a one-part, low modulus, neutral-curing siliconesealant for use in high-movement weathersealing applications. DOWSIL 790 Silicone BuildingSealant has excellent primerless adhesion to concrete and most porous substrates. Available in a widevariety of colors.DOWSIL Contractors Weatherproofing SealantDOWSIL Contractors Weatherproofing Sealant is a one-part, medium modulus, neutral-curingsilicone sealant for use in non-specified general weathersealing applications. Available in a wide varietyof colors.DOWSIL Contractors Concrete SealantDOWSIL Contractors Concrete Sealant is a one-part, low modulus, neutral-curing silicone sealant foruse in non-specified tilt-up concrete weathersealing applications. DOWSIL Contractors ConcreteSealant has excellent primerless adhesion to concrete and most porous substrates. Available in a widevariety of colors.DOWSIL 123 Silicone Seal and DOWSIL Silicone Seal Custom Designs H.C.DOWSIL 123 Silicone Seal is a preformed, low modulus silicone extrusion that can be used as abridge joint in a variety of applications, including restoration of failed sealant joints.DOWSIL 123 Silicone Seal HC is a custom extrusion or mold made of higher durometer siliconerubber used in custom applications. Widths from 1" (25 mm) to 12" (300 mm) and custom shapes areavailable in a wide variety of colors and textures.DOWSIL 795 Silicone Building Sealant, DOWSIL 791 Silicone Weatherproofing Sealant,DOWSIL 756 SMS Building Sealant or DOWSIL 758 Silicone Weather Barrier Sealant may beused as an adhesive.For more information, see the EIFS Restoration Guide, Form No. 62-510.DOWSIL 756 SMS Building SealantDOWSIL 756 SMS Building Sealant is a one-part, medium modulus, neutral-curing silicone sealantdesigned specifically for weathersealing sensitive substrates where the aesthetic performance of thesealant is important. The sealant is intended for weathersealing skylights, glass facades, porous naturalstone, and panel systems where staining and residue rundown streaking must be minimized.DOWSIL 758 Silicone Weather Barrier SealantDOWSIL 758 Silicone Weather Barrier Sealant is a neutral, one-part silicone sealant designed foradhering to low energy surfaces common in sheet or peel-and-stick weather-resistant barriers. Availablein white.5

DOWSIL Parking Structure SealantsDOWSIL NS, SL and FC Parking Structure Sealants are low modulus, neutral-curing silicone sealantsfor use in vertical and horizontal joints in parking structures and stadiums. DOWSIL NS ParkingStructure Sealant is a one-part, non-sag sealant for vertical or horizontal joints. DOWSIL SL ParkingStructure Sealant is a one-part, self-leveling sealant for horizontal joints. DOWSIL FC ParkingStructure Sealant is a two-part, fast-curing sealant for dynamic moving horizontal expansion joints.Available in gray.For more information, see the Parking Structure Sealants Installation Guide, Form No. 62-481.PrimersDow has a full line of high-performance primers for sealants. Primers are used to enhance adhesion ofsealants to specific substrates.DOWSIL 1200 OS PrimerDOWSIL 1200 OS Primer is a one-part, VOC-compliant silane primer for use with DOWSIL sealants in many applications. Available in clear.DOWSIL Primer-C OSDOWSIL Primer-C OS is a one-part, low VOC, film-forming primer for use with DOWSIL sealants on painted and plastic surfaces to promote rapid adhesion. The primer features aunique fluorescent feature using a UV flashlight (365 nm wavelength) to identify areas where primerwas applied.DOWSIL Construction Primer PDOWSIL Construction Primer P is a one-part, film-forming primer for use with DOWSIL sealantson porous and cementitious surfaces to promote adhesion. DOWSIL Construction Primer P should notbe used with DOWSIL 790 Silicone Building Sealant, DOWSIL Contractors Concrete Sealant orDOWSIL Parking Structure Sealants.6

Building Sealant Recommendations and Surface Preparation Guidefor Weatherseal ApplicationsWeathersealDow has a full line of high-performance primers for sealants. Primers are used to enhance adhesion.DOWSIL 756 SMSBuilding SealantDOWSIL 790Silicone BuildingSealant1SubstrateDOWSIL 791SiliconeWeatherproofingSealantDOWSIL 795Silicone BuildingSealantSurface PrepConcrete and MasonryBrickLimited Data/Field TestNo Primer1200 OS/Primer PPrimer PConcreteField TestNo Primer1200 OS/Primer PPrimer PMortarPrimer PNo PrimerPrimer PPrimer PLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestEIFS2All Manufacturers3StoneGraniteNo PrimerNo PrimerLimited Data/Field Test1200 OS/Primer PLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestMarble41200 OS/Primer PLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimestone8(Natural Stone)Sandstone8Paints1200 OS/Primer PLimited Data/Field TestLimited Data/Field TestPrimer PLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestPrimer PAcrylic LatexLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestNo PrimerLimited Data/Field TestNo Primer1200 OS/Primer PLimited Data/Field Test1200 OSNo PrimerNo PrimerLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestKynarNo PrimerLimited Data/Field TestNo PrimerPrimer-C OSDuranarNo PrimerLimited Data/Field TestNo PrimerPrimer-C OSTravertineDuracronPolyester PowderCoating7PolyurethanePolyvinyl Chloride(PVC)FluoropolymerDuranar SunstormLimited Data/Field TestLimited Data/Field TestNo PrimerPrimer-C OSFluroponLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestPrimer-C OS7

DOWSIL 756 SMSBuilding SealantDOWSIL 790Silicone BuildingSealant1SubstrateDOWSIL 791SiliconeWeatherproofingSealantDOWSIL 795Silicone BuildingSealantSurface PrepMetalsAluminum – ChromateConversion, AlodineAluminum – Mill FinishNo PrimerLimited Data/Field TestNo Primer1200 OS1200 OS1200 OSAluminum – AnodizedNo Primer1200 OSNo PrimerNo PrimerCopperLeadNo PrimerNo PrimerDo Not UseDo Not UseNo PrimerNo PrimerLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestGlass6Coated GlassNo Primer1200 OSNo PrimerNo PrimerClear GlassNo PrimerNo PrimerNo PrimerNo PrimerRed Lead PrimerLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestWeatheredLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestStainlessSteelLimited Data/Field TestLimited Data/Field Test1200 OS1200 OSGalvanizedNo Primer1200 OSNo Primer1200 OS/Primer PCold RolledLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestLimited Data/Field TestPVCLimited Data/Field TestLimited Data/Field Test1200 OS/Primer PNo PrimerAcrylicLimited Data/Field TestDo Not UseLimited Data/Field TestLimited Data/Field TestDo Not UseDo Not UseLimited Data/Field TestLimited Data/Field TestPlasticsPolycarbonateKey: 1200 OS: DOWSIL 1200 OS Primer; Primer-C OS: DOWSIL Primer-C OS; Primer P: DOWSIL Construction Primer P.Dow must test all materials for adhesion in structural applications.Field adhesion tests must be performed at the jobsite to verify sealant adhesion.1When using a primer with DOWSIL 790 Silicone Building Sealant, apply the primer before installing backer rod and allow the primer to dry. Coldweather and porous surfaces require additional drying time.2Do not apply sealant to EIFS finish coat unless approved by EIFS manufacturer.3Cleaning procedures for EIFS systems should be followed (page 73).4The extremely porous nature of some marble, particularly white marble, can contribute to the potential for fluid migration into this substrate. Contact aDow Specialist when working with marble.5Laminated glass with polyvinyl buyvol (PVB) interlayer may delaminate up to 1/4" at the edges when in contact with a sealant.6Do not use DOWSIL 790 Silicone Building Sealant on copper sputter coated glass.7See Organic Solvent Usage in this Dow Americas Technical Manual (page 69) for comment.8Some limestone and other porous stone substrates contain iron and other impurities that can interact with DOWSIL 756 SMS Building Sealant, causingdiscoloration of the sealant and/or substrate. Prior to use, DOWSIL 756 SMS Building Sealant should be tested for compatibility with these substratesusing water immersion.This surface preparation guide is intended to aid in proper selection of surface preparation techniques and primers, if necessary, to gain adhesion that meetsDow;s requirements. The suggestions in this guide are not blanket-approval recommendations; Dow requires all surface prep recommendations in this guidebe verified by field or shop adhesion testing and documented prior to starting the project for each substrate/sealant combination. Failure to verify anddocument adhesion results may result in adhesion loss that is not covered by the Dow Warranty. Recommendations in this guide have been shown to be thebest overall recommendations but do not cover every substrate for each material type or finish listed in this guide. Additionally, substrate manufacturersshould be contacted to obtain recommendations for proper cleaning solvents for use with their materials. The entire Weatherproofing section of this manualshould be read and understood before proceeding with the evaluations. The following sections must be followed to verify and document adhesion: Substrate Cleaning Procedure (page 69)“Two Cloth” Cleaning Method (page 70)Primer Application Procedure (page 71)Field Adhesion Testing Procedure (page 78)Field Adhesion Hand Pull Test Criteria (page 79)Field/Shop Adhesion Log and Sealant Quality Control Logs (pages 82-84)8

StructuralAll structural applications must be tested by the Dow test lab.DOWSIL 795Silicone BuildingSealantDOWSIL 983Structural GlazingSealantSubstrateDOWSIL 995Silicone StructuralSealantDOWSIL 121Structural GlazingSealantSurface PrepPaintsAcrylic LatexLimited Data/Lab TestDuracronLimited Data/Lab TestLimited Data/Lab TestLimited Data/Lab TestPrimer-C OSPrimer-C OSPrimer-C OSPrimer-C OSPrimer-C OS, 1200 OSPrimer-C OS, 1200 OSNo PrimerPrimer-C OSKynarPrimer-C OSPrimer-C OS, 1200 OSNo PrimerPrimer-C OSDuranarPrimer-C OSPrimer-C OSPrimer-C OSPrimer-C OSDuranar SunstormPrimer-C OSPrimer-C OSPrimer–C OSLimited Data/Lab TestFluroponPrimer-C OSPrimer C OSPrimer-C OSLimited Data/Lab TestNo Primer, 1200 OSNo Primer, 1200 OS1200 OS1200 OSNo PrimerNo Primer, 1200 OS1200 OS1200 OS1200 OS1200 OS1200 OS1200 OSClearNo PrimerNo PrimerNo PrimerNo PrimerFloatNo PrimerNo PrimerNo PrimerNo PrimerLaminated5No PrimerNo PrimerNo PrimerNo PrimerPolyester Powder Coating7FluoropolymerMetalsAluminum – ChromateConversion, AlodineAluminum – AnodizedSteelStainlessGlass – Surface to be Glazed toPlateNo PrimerNo PrimerNo PrimerNo PrimerTintedNo PrimerNo PrimerNo PrimerNo PrimerCeramic Frit CoatingNo PrimerNo PrimerNo PrimerNo PrimerReflective GlassNo PrimerNo PrimerNo PrimerNo PrimerLow E High (T) GlassNo PrimerNo PrimerNo PrimerNo PrimerKey: 1200 OS: DOWSIL 1200 OS Primer; Primer-C OS: DOWSIL Primer-C OS.Dow must test all materials for adhesion in structural applications.Field adhesion tests must be performed at the shop or jobsite to verify sealant adhesion.5Laminated glass with polyvinyl buyvol (PVB) interlayer may delaminate up to 1/4" at the edges when in contact with a sealant.See Organic Solvent Usage in this Dow Americas Technical Manual (page 29) for comment.7This surface preparation guide is intended to aid in proper selection of surface preparation techniques and primers, if necessary, to gain adhesion that meetsDow’s requirements. The suggestions in this guide are not blanket-approval recommendations; Dow requires all surface prep recommendations in this guidebe verified by field or shop adhesion testing and documented prior to starting the project for each substrate/sealant combination. Failure to verify anddocument adhesion results may result in adhesion loss that is not covered by the Dow Warranty. Recommendations in this guide have been shown to be thebest overall recommendations but do not cover every substrate for each material type or finish listed in this guide. Additionally, substrate manufacturersshould be contacted to obtain recommendations for proper cleaning solvents for use with their materials. The entire Weatherproofing section of this manualshould be read and understood before proceeding with the evaluations. The following sections must be followed to verify and document adhesion: Substrate Cleaning Procedure (page 29)“Two Cloth” Cleaning Method (page 29)Primer Application Procedure (page 30)9

Silicone Structural GlazingIntroductionSilicone structural glazing utilizes a high-performance silicone sealant to attach glass, metal or otherpanel materials to a metal frame in lieu of gaskets and mechanical attachments. The windload stressesare transferred through the structural silicone sealant to the structure of the building. The structuralsilicone sealant must maintain its adhesive and cohesive properties in order to support the panelsunder windload.Only silicone sealants are suitable for use in structural glazing applications. A considerable amount oftime has been spent developing and testing silicone sealants to meet the needs of structural glazingapplications. Whenever a silicone sealant is used to structurally attach panels, a comprehensivequality control procedure must be established to ensure the smooth, efficient, trouble-free completionof the project.Specific quality control procedures must be followed on all structural glazing projects in order to obtaina Dow Structural Warranty.Structural Joint Design10

Structural Glazing DesignStructural BiteStructural bite is the minimum width or contact surface of the silicone sealant on both the panel andthe frame. The structural bite requirement is directly proportional to the windload on the building andthe size of the glass. The higher the design windload and the larger the size of the glass, the greater thestructural bite requirement. The structural bite must be sized appropriately to allow the windload onthe glass or panel to be transferred to the structure. The structural bite for windload (live load) iscalculated using the specified windload, glass or panel dimension and sealant design strength of20 psi (14,000 kg/m2 or 138 kPa).Structural Bite CalculationFollowing is the calculation used to determine the required structural bite dimension:Bite (inches) 0.5 * short span length (ft) * windload (psf)12 in/ft* sealant design strength (20 psi)For example, a 4' x 8' lite of glass, exposed to a 60 psf windload, requires a silicone bite of 1/2". Alwaysround up to the nearest 1/16" and never round down.0.5 * short span length (mm) * windload (kg/m2)Bite (mm) sealant design strength (14,000 kg/m2)For example, a 1219 mm x 2438 mm lite of glass, exposed to a 290 kg/m2 windload, requires a siliconebite of 13 mm. Always round up to the nearest millimeter and never round down.Bite (mm) 0.5 * short span length (mm) * windload (kPa)sealant design strength (138 kPa)For example, a 1219 mm x 2438 mm lite of glass, exposed to a 3.5 kPa windload, requires a silicone biteof 16 mm. Always round up to the nearest millimeter and never round down.11

DeadloadIn unsupported deadload designs, the weight of the panel places constant load upon the sealant.DOWSIL brand structural sealants can support the weight of the panel or glass when used withinthe following guidelines: For DOWSIL 795 Silicone Building Sealant, DOWSIL 983 Structural Glazing Sealant,DOWSIL 995 Silicone Structural Sealant and DOWSIL 121 Structural Glazing Sealant,the allowable deadload design strength is 1 psi or 6.9 kPa.The weight of the panel divided by the total silicone contact area must not exceed 1 psi, thedeadload design strength of the sealant. Insulating glass unit manufacturers require deadloadsupport for their insulating glass units.The deadload structural bite requirement is calculated as follows:Bite weight of glass in lbsealant contact length (inches) * sealant design strength (1 psi)For example, a 4' by 8' lite of monolithic glass at a weight of 3.3 psf will have a weight of 105.6 lb and aglass perimeter of 288". Based on a 1 psi deadload design strength, a bite of 3/8" is required.Bite (mm) weight of glass in Nsealant contact length (m) * sealant design strength (6.9 kPa)Sealant Design Strength (SDS) (6.9 kPa) 12weight of glass (N)sealant contact length (m) * bite (mm)

For example, a 1219 mm by 2438 mm lite of monolithic glass at a weight of 145 N/m2 will have aweight of 431 N and a glass perimeter of 7.314 meters. Based on 6.9 kPa deadload design strength,a bite of 9 mm is required.Sloped GlazingSloped glazing is a form of structural glazing used in skylights and similar non-vertical applications.Conventional structural glazing guidelines can be followed for sloped glazing with modifications to thewindload accounting for the slope. The structural glazing calculation takes into account the weight of theglass counteracting the negative design windload on the building. The flatter the slope of the glazingsystem, the greater the reduction in the windload effect on the structural joint.For many slope-glazed systems, the glass sets on a gasket and the structural joint is installed to the edgeof the glass. The sealant in this application acts as both the structural seal and the weatherseal. Dowpermits the use of its sealants in this manner provided that the joint maintains an aspect ratio o

Dow has a full line of high-performance silicone structural sealants. Following is a brief summary of . DOWSIL 123 Silicone Seal is a preformed, low modulus silicone extrusion that can be used as a bridge joint in a variety of applications, including restoration of failed sealant joints.