Guidelines for thermally-curved glass in the building … · toughened curved glass units has,...

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Guidelines for thermally-curvedglass in the building industry

BF-Bulletin 009 / 2011


Table of contents

1.0 Introduction . . . . . . . . . . . . . . . . . 22.0 Area of validity . . . . . . . . . . . . . . . 33.0 Manufacture and geometry . . . . . 34.0 Construction regulations . . . . . . . 54.1 General remarks . . . . . . . . . . . . . . 54.2 Thermally curved glass . . . . . . . . . 55.0 Building products . . . . . . . . . . . . . 65.1 General remarks . . . . . . . . . . . . . . 65.2 Curved float glass (CA) . . . . . . . . . 65.3 Curved thermally toughened safety . .

glass (CTS) . . . . . . . . . . . . . . . . . . 65.4 Curved heat-strengthened glass

(CHS) . . . . . . . . . . . . . . . . . . . . . . 65.5 Curved laminated glass and lamina-

ted safety glass (CL, CLS) . . . . . . . 65.6 Curved insulating glass units

(CIG) . . . . . . . . . . . . . . . . . . . . . . 65.7 Designing with curved glass . . . . . . 76.0 Building physics . . . . . . . . . . . . . . 76.1 General remarks . . . . . . . . . . . . . . 76.2 Thermal insulation and solar control 76.3 Sound insulation . . . . . . . . . . . . . . 77.0 Safety with glass . . . . . . . . . . . . . . 87.1 Special safety glazing . . . . . . . . . . 87.2 Proof against danger to the visiting .

public . . . . . . . . . . . . . . . . . . . . . . 87.2.1 Appropriate glass products . . . . . . 88.0 Visual quality . . . . . . . . . . . . . . . . 89.0 Tolerances . . . . . . . . . . . . . . . . . . 9

10.0 Dimensioning . . . . . . . . . . . . . . . 1310.1 Peculiarities, in terms of structural

physics, as compared to flat glasspanes . . . . . . . . . . . . . . . . . . . . . 13

10.2 Climatic pressures applying to curvedinsulating glass . . . . . . . . . . . . . . 13

10.3 Bases of calculation . . . . . . . . . . . 1310.4 Fitness for use . . . . . . . . . . . . . . . 1410.4.1 Limitation of the degree of

deflection of the glazing . . . . . . 1410.4.2 Limitation of the degree of

deflection in the substructure . . 1411.0 Storage and transport . . . . . . . . 1412.0 Glazing . . . . . . . . . . . . . . . . . . . . 1512.1 General remarks . . . . . . . . . . . . . . 1512.2 Instructions in respect of design and

construction matters . . . . . . . . . . 1512.3 Necessary rebate width . . . . . . . . 1513.0 Blocking . . . . . . . . . . . . . . . . . . . 1513.1 Definitions . . . . . . . . . . . . . . . . . . 1614.0 Measurement . . . . . . . . . . . . . . . 1715.0 Literature . . . . . . . . . . . . . . . . . . 1716.0 Contact persons in the various

German Federal States for theacquisition of an ExceptionalApproval (ZiE) . . . . . . . . . . . . . . 18

17.0 Standards, regulations anddirectives . . . . . . . . . . . . . . . . . . 19

18.0 Further reading . . . . . . . . . . . . . 20


1.0 Introduction

The use of glass in the building envelopeis a practice increasingly popular amongboth planners and persons commissio-ning building projects. The developmentthat glass as a building material has seenin recent decades has shown that limitscan hardly any longer be set to the materi-al’s application in this way. It makes avai-lable to the planner and the commissio-ning party a broad spectrum of differentdesign possibilities. There thus arise multi-functional, geometrically complex façades,the execution of which requires not onlyflat but also curved types of glazing.

The earliest glass façades were erectedusing almost exclusively flat glass. Rese-arch as well, in recent decades, has focu-sed primarily on these types of glazing.Curved glass tended to be used only sel-dom. Thanks to the further developmentof production processes and other techni-ques of processing, like the use of coa-tings with special functions such as heat-insulation and solar control, the fields ofapplication of both flat and curved glassbecame larger.

These guidelines are intended to providethe user (architect, planner, or builder exe-cuting the project) with some orientationin the use of curved glass, both in theplanning and design phase and in thephase of actual execution, and also to gi-ve him some necessary pointers in res-pect of important emerging questions.Descriptions are provided of the basicconstruction regulations applying and po-

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inters given regarding dimensioning ofglass and regarding glazing itself. In addi-tion, the basic principles for the assess-ment of the visible quality of curved glassare explained and statements made as topermissible tolerances. Pointers regardingtransport and installation are also given.

In the case of questions arising which gobeyond the limits of these general guideli-nes, or relate specifically to individual ca-ses, the manufacturers or planning officesconcerned should be contacted directly.

2.0 Area of application

These guidelines are valid for thermally-curved glass intended for use in the buil-ding industry (use in the building envelo-pe and in the extension of existing buil-dings to form annexes and other structu-res).

As regards special applications – e.g. inship- and boat-building, as yacht glass,or in furniture-making – questions as tothe products that might be used, their to-lerances, their visual quality etc. shouldbe directed to the manufacturers of saidproducts.

3.0 Manufacture andgeometry

Since the beginning of the modern historyof the bending of glass for use as an ar-chitectural material – in the middle of the19th Century in England – the basic prin-ciple of manufacture of thermally-curvedglass units has not substantially altered.As a rule, the principle applied is the prin-ciple of “gravity bending” illustrated in Fig.1. This method involves laying the flat flo-at glass blank on a bending mould andheating it, in a bending furnace, to tempe-ratures of between 550 and 620 °C. On-ce the softening range has been reached,the blank will, by force of gravity, sink intothe mould or, where the mould is convex,lay itself over this latter. It is the subse-quent cooling-off phase that determinesthe properties of the end-product.

For the manufacture of curved float glassa very slow cooling-off must be conduc-ted. The process goes on, as a rule, for se-veral hours, so as to achieve an end pro-duct almost devoid of intrinsic stress andeasily cut and shaped.

A rapid cooling-off process, on the otherhand, produces a curved glass that is eit-her of the heat-strengthened or of thetoughened type. The manufacturing pro-cess of heat-strenthened and thermallytoughened curved glass units has, howe-ver, altered as a result of the continuingdevelopment of machine technology. Mo-dern bending furnaces for manufacturingheat-strenthened and thermally toughe-ned glass units work with movable ben-ding moulds which bring the heated-up

blank, from both sides, into the desiredform and also hold it in this form duringthe whole process of heat strengtheningand toughening. The bending and cooling-off take place here within the same furna-ce unit.

Simple, however, as the principle of glass-bending may be in itself, its actual puttinginto practice is a difficult and demandingmatter. Whether or not a bending processis successful depends on a whole seriesof parameters. Besides the determininggeometrical conditions, coatings and theparticular basic glass used (e.g. low-iron-oxide-content glass, or so-called “whiteglass”) also exert a significant influenceon the decisive production phases of hea-ting-up and cooling-off. Also decisively im-portant for the quality of the end-product,of course, are such factors as the amountof experience possessed by the enterpriseperforming the bending and the technicalcharacteristics of the bending furnacesused.

Whether it will be possible, therefore, inany given case, to realize the desired ben-ding geometry in combination with thechosen glass construction – possibly alsowith coating – is a matter that depends al-so on the particular manufacturer(s) invol-ved, so that the making of general state-ments about possible bend radii andglass constructions is only possible to alimited degree.

As a matter of general principle, however,it can be said that more elaborate geome-tries, such as spherical bends and bows,are generally only possible in the form of

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(Bild 2)



annealed float glass. In cases where cur-ved laminated glass (CL) or curved lami-nated safety glass (CLS) are required, theindividual panes can be laid together onthe bending mould during the float glassbending process. For this reason the tole-rances of the individual panes are, for themost part, significantly lower than in thecase of laminated safety glass manufactu-red from heat-strengthened and thermallytoughened curved glass, since in this casethe panes can only be manufactured pa-ne-by-pane.

When manufacturing curved panes a fun-damental distinction is made betweenslightly curved glazing units, with a radiusof curvature of over two metres, and strong-ly curved glazing units, with smaller radiiof curvature. Moreover, a distinction is al-so made between glass curved on a singleaxis (i.e. cylindrically) and glass curved ona double axis (i.e. spherically). The ther-mal-bending process allows the realizationof very small bend radii. The exact valuesdepend on the individual manufacturer,but radii as small as 100 mm are possiblewhere glass-thicknesses lie above 10 mmup to about 300 mm.


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Step 1:Building of a bendingmould and laying of theflat glass-blank on themould

Step 2:Heating-up of theglass to between550 and 620 °C

Step 3:The blank sinks intothe bending mould

Step 4:� In the case of float glass, slow

cooling-off (several hours)� In the case of heat-strengthened

and thermally toughened glassunits, fast cooling-off.

Fig. 1: Principal Steps in Manufacture


4.0 Construction regulations

4.1 General remarksA fundamental distinction is to be madebetween regulations, or standards, bea-ring on the products (i.e. their inherentproperties) and regulations or standardsbearing on the use or application. Where-as product standards contain regulationsbearing on manufacture and specifica-tions regarding the technical properties ofthe products in question, standards anddirectives relating to use and applicationdeal rather with requirements specificallyin building terms, and describe the requi-red proofs of the load-bearing capacityand fitness for use of a particular buildingproduct or particular building type withinthe context of a built construction.

Product standards are taken up uniformlyall over Germany into Construction Pro-ducts Lists A, B and C, published by theDeutsches Institut für Bautechnik in agree-ment with the Senior Building SupervisoryAuthorities (SBSA) in all the individualGerman federal states.

Standards and directives relating to useand application, on the other hand, arepublished by separately in each of theseGerman federal states as part of the sta-te’s respective List of Technical Constru-ction Specifications. Here, therefore, itcannot be assumed that the same rulesand stipulations apply all across the terri-tory of the Federal Republic of Germany.Rather, there must always be enquiredand investigated, in each federal state,which regulations currently apply there.

4.2 Thermally curved glassThermally curved glass is not listed in theConstruction Products Lists A, B, or C. Thismeans that, from the point of view of con-struction law, we are dealing here with anon-regulated building product. In this ca-se, fitness for use can only be proven viaa National Technical Approval (Allgemeinebauaufsichtliche Zulassung, or AbZ) or viaa European Technical Approval (ETA). Inthe case where neither of the just-namedproofs of fitness for use is extant, it will benecessary to make an application to thecompetent Senior Building SupervisoryAuthority of the German federal state con-cerned – or, where appropriate, to someother office authorized by the latter – foran Exceptional Approval (Zustimmung imEinzelfall, or ZiE).

The “Technical Regulations for the Use ofGlazing with Linear Supports” (hereinafterreferred to by the German acronym: TRLV)[1] and the “Technical Regulations for theUse of Fall-Proof Glazing” (hereinafter refer-red to by the German acronym: TRAV) [2],which have currently been introduced intoall the Federal German states, govern con-struction regulations and required proofs ofload-bearing safety and fitness for use inprinciple also for curved vertical glazing.Containing as they do stipulations regar-ding glass-types that may be used, officialrequirements in terms of construction,and instructions as to glass-design and -dimensioning, etc. the TRLV constitute afoundation for the TRAV.

For curved glass a National Technical Ap-proval is required in which the propertiesof the product and the area of its applica-tion are explicitly stated. Curved verticalglazing units (without fall-proof functions)may then without further ado be designedand dimensioned according to the terms

of the TRLV. In the case where the area ofapplication specified in the National Tech-nical Approval comprehends the TRLV, it ispermissible that the curved glass also beused for the manufacture of fall-proof gla-zing in the meaning of the TRAV. In respectof proofs of fitness for use and of applica-bility there then additionally apply the sti-pulations of the Construction Products ListA Part 2 or Part 3. These stipulations re-quire in such cases a General Building In-spection Test Certificate (Allgemeines bau-aufsichtliches Prüfzeugnis, or AbP).

In the DIN standard which will in future re-gulate the design and dimensioning ofglazing units in Germany, DIN 18008, con-structions with curved glass are not inclu-ded in the ambit of the regulation. Likewi-se, no description is included in this newgeneral standard of that application ofcurved vertical glazing with linear supportswhich is presently regulated by the TRLV.This means that the application of the bu-ilding product “curved glass” will hencef-orth only be possible via an official gene-ral approval – be it a National TechnicalApproval for Germany (AbZ) or a EuropeanTechnical Approval (ETA) – or an Exceptio-nal Approval (ZiE).

Neither the permissble bending strengthstated in the TRLV nor the designing anddimensioning procedures prescribed therefor the taking into account of climaticpressures may be used for the design anddimensioning of curved glazing units.Here, there apply essentially rather thedeterminations of the National TechnicalApproval (AbZ) bearing on the specificproduct(s).The proofs of impact-resistance stipulatedin Table 2 of the TRAV likewise do not ap-ply to curved glass.

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5.0 Building products

5.1 General remarksIn the following sections there are listedthe various different curved building pro-ducts, in accordance with the Europeanproduct standards for flat glass units. Byway of supplement to this, there are poin-ted up the relevant differences here bet-ween flat glass and curved glass, or thespecial characteristics of the latter.

In order to distinguish flat from curvedglass, and to set the products off fromone another as regards their inherent pro-perties, we introduce here the abbrevia-tion “c” (for “curved”) as a supplement tothe already-current abbreviations for glassbuilding products.

5.2 Curved float glass(curved annealed glass, CA)The starting product for curved floatglass (CA) is described in EN 572-2.This European Standard defines floatglass as a flat, transparent, clear or colou-red soda lime silicate glass with paralleland fire-polished surfaces, manufacturedby continuous pouring and flowing over amolten metal bath.

In addition, EN 572 also sees other basic-glass products, such as ornamental glass,wired glass, wired plate glass and profiledglass, as capable of being manufacturedas curved-glass products. Here, however,the manufacturers should be consulted.The product standards for these productslikewise refer only to flat glass.

5.3 Curved thermally toughened safetyglass (CTS)The European Product Standard EN12150-1 describes only flat fully-toughe-ned glass. However the “informative” se-ction of this Standard (Annex B) says:

„Curved thermally-toughened soda li-me silicate safety glass is a glass towhich a fixed shape has been given inthe course of the production process.It does not form part of the object ofthe present Product Standard, sincethe available data are not sufficient forstandardization. Notwithstanding thisfact, the information contained in thepresent Product Standard relative tothicknesses, edgework and fracturepatterns can also be applied to curvedthermally-toughened soda lime silicatesafety glass.“

5.4 Curved heat-strengthened glass(CHS)The European Product Standard EN 1863-1 describes only flat heat-strengthenedglass. However the “informative” sectionof this Standard (Annex B) says:

„Curved heat-strengthened soda limeglass is a glass to which a fixed shapehas been given in the course of theproduction process. It does not formpart of the object of the present Pro-duct Standard, since the available da-ta are not sufficient for standardiza-tion. Notwithstanding this fact, the in-formation contained in the present Pro-duct Standard relative to thicknesses,edgework and fracture patterns can al-so be applied to curved heat-strengthe-ned soda lime glass.”

It is especially to be noted that above allthe fracture-pattern behaviour typical of


flat heat-strengthened glass is not trans-ferrable with exactitude to curved heat-strengthened glass. In Germany, a Natio-nal Technical Approval is required for he-at-strengthened glass and for laminatedsafety glass made from heat-strengthenedglass.

5.5 Curved laminated glass andlaminated safety glass (CL, CLS)The European Product Standard EN14449 describes only flat laminated glassand laminated safety glass.

For use in Germany, however, LSG must,in addition, comply with the requirementsset by the Construction Products List A,Part 1, Item 11.14. That list defines LSGas a building product with interlayers ma-de from polyvinyl butyral (PVB) or madefrom other interlayer materials the fitnessfor use of which has already been proven.To discover which interlayer other than aPVB interlayer it is permissible to use incurved LSG, the relevant National Techni-cal Approval should be consulted.Simple laminated glass, on the other hand,is a building product making use of interlay-ers or interstrata of a different type, theproperties of which are not proven on thebasis either of the Construction ProductsList or of a National Technical Approval.

5.6 Curved insulating glass units (CIG)The European Product Standard EN 1279is applicable to curved IGU with certainlimitations. In Part 1 of EN 1279 (Section4.6) we find the following formulation:

„Units with a bend radius of > 1000mm are in compliance with the presentProduct Standard without having un-dergone the additional tests for curvedtest specimens. Units with a bend ra-dius of 1000 mm or less are in compli-

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ance with this Product Standard wherethe further condition is fulfilled thatcurved test specimens with the sameor with a smaller bend radius satisfythe requirements in respect of water-vapour diffusion set by EN 1279-2. Thetest specimens should be curved withthe bending axis parallel to their lon-gest side.“

In principle, it is also possible to executetriple-glazed insulating glass units in theform of curved glazing. Here, however, themanufacturers should always be consul-ted first about feasibilities (i.e. in terms ofsize and scale, glass composition, glasstypes, technical indices etc.) and tolerances.

5.7 Designing with curved glassIn principle, the working of designs intocurved glass – by means, for example, ofenamelling, screen- or digital printing,printed films, sandblasting, fusing, or par-tial coating – is possible.The resulting properties are to be determi-ned individually, case by case, and the fe-asibilities and tolerances are to be clari-fied with the respective manufacturers.

6.0 Building Physics

6.1 General remarksThe Energy Performance of Buildings Dire-ctive (EPBD) formulates targets and gui-delines aimed at reducing the energy con-sumption of buildings and increasing theuse of renewable energy-forms. With thisaim in view, the EPBD states, on a pan-European level, a series of minimum re-quirements, which can then be correspon-dingly altered or adapted within the indivi-dual EU member states. This means that,among other requirements, requirementsare stated regarding the permissible pri-mary energy consumption of a building.Germany’s specific national implementa-tion of this pan-European EU Directive, theFederal German Energy-Saving Ordinance(Energieeinsparverordnung, or EnEV), in-volves placing statutory requirements on,among other things, heat insulation, andheat-absorption in summer, for such buil-ding components as windows and façades.

6.2 Thermal insulation and solar controlBoth curved and flat glazing units mustsatisfy the statutory requirements just re-ferred to. It is possible that there may beapplied here heat-insulation and solar-control coatings. Important particularly inthe case of solar-control coatings are, be-sides the functional requirements, alsothe aesthetic ones (e.g. the reflectance ofthe coated glass, the specific colouringlent to the glazing unit by the coating orby the glass substrate).

When establishing required visual proper-ties, use should be made right from thestart, particularly in the case of larger-scale buildings and constructions, ofsamples prepared on the same scale asthe actual building component, so as to

come to an understanding with the manu-facturer about the specific optical qualityto be expected. An initial determinationof the specific type of product requiredcan, however, be carried out using so-cal-led “hand samples”, which have, as a ru-le, dimensions of 200 x 300 mm.

Just what possibilities exist as regards co-atings is something which depends onthe geometry of the glazing unit, the glasscomposition, its size etc. and will need tobe clarified on a case-by-case basis withthe manufacturer of the curved glass. Gi-ven the large number of the just-namedparameters, no prior general determina-tion of attainable Ug values, g values etc.is possible. The statement given of Ug va-lues and of light and solar radiant heatfactors is, as a rule, that for flat glazingunits with the same glass structure. Theprocedure by which these values are arri-ved at is that stipulated in EN 673 andEN 410.

6.3 Sound insulationThe measurement of the sound insulationrating is carried out in accordance with ENISO 140 and the establishment of theevaluated sound reduction index is carriedout according to EN ISO 717. The measu-rement is effected on flat glazing units ofthe size: 1.23 x 1.48 m.

The transferral of these specifications tocurved glazing is only limitedly possible,since the emitting surface is larger than inflat planes of a comparable size. Here, atest conducted by some appropriate tes-ting institute is to be recommended.

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7.0 Safety with glass

7.1 Special safety glazingFlat as well as curved glass must fulfil re-quirements as regards resistance to ma-nual attack, projectile attack, bullet attackand explosive impact. Whether every oneof the just-named requirements – takinginto account the window- and façade-con-struction – can actually be fulfilled, andwhether testing procedures for flat glazingcan be carried over and applied to curvedglazing are questions that must be clari-fied on a case-by-case basis with the res-pective manufacturer, or a testing institute.

7.2 Proof against danger to the visitingpublicFor a glazing unit to be proof against dan-ger to the visiting public means that, assu-ming a normal and proper use of said gla-zing unit, the risk of accident has been as-sessed and adapted to by means of ap-propriate construction measures.

Intended here is the safety of glazing unitswhich are situated adjacent to areas whe-re people regularly pass and assemble.That is to say, it may indeed be permittedthat the building component glass shatterunder the effect of some force, but thefragments of it which, in such a case, falldown into these areas may not be such asto lead to dangerous injuries among thepassing and assembling public.

Responsibility for reducing the risk of acci-dent to a minimum lies with the party com-missioning the building or other work. Therequirements relative to safety are to beset, or to be examined beforehand, by theplanner, and are to be agreed and coordi-nated with the competent authorities.These safety requirements must also befulfilled by curved glazing units, in the ca-

se where the latter are applied in a man-ner corresponding to that just described.

7.2.1 Appropriate glass productsThe requirement that constructions be pro-of against danger to the visiting public canbe fulfilled, as regards the area of glass, bymeans of a properly functioning glazing sys-tem and the application of safety glass.The Federal German Workplaces Ordinance(Arbeitsstättenverordnung, or Arb- StättV)and the rules and regulations of the Acci-dent Prevention & Insurance Associationmust be complied with.

A generally important point of reference he-re is the document BGI/GUV–I 669 of theFederal German Statutory Accident Insu-rance. According to this document, the fol-lowing types of glass fulfil the safety requi-rements and can be used as safety glass:� thermally toughened safety glass and

heat soaked thermally tougehenedsafety glass (in Germany ESG-H)

� Laminated safety glass, and� Translucent plastics with comparable

safety properties.The glass referred to here is flat glass.Curved glass may, where conditions areright, be used as safety glass, provided thatproof is provided of its possession of theproperties required.In the case of TG the properties concernedwould be, among others, those relating toits behaviour during breakage; in the caseof LSG they would be the properties of theinterlayer, as stipulated by the ConstructionProducts List, and, where required, residualload-bearing capacity. These propertiesmust be confirmed to by a National Techni-cal Approval or within the framework of anExceptional Approval (ZiE).In the case of statutory accident-preventionand statutory accident-insurance regula-tions, the insuring body may, in certain in-dividual cases, need to be consulted regar-


ding the use of the products.That is to say, it must be ensured that theglass construction in question is appropria-te for the intended application. Each sepa-rate area and aspect of its use must fulfilthe requirements in terms of safety.

8.0 Visual quality

Basically the “Guideline to Assess the Visi-ble Quality of Glass in Buildings” [3] is va-lid. In addition, however, to the allowablediscrepancies named in Section 3 of thisGuideline there are also allowable, in thecase of curved glass: burn marks, coatingdefects, surface marks and impressions.

Tests of visual quality are conducted bydiffuse daylight (e.g. during times of over-cast sky), without direct solar radiation orartificial lighting, and from a distance ofat least 3 m, looking from the inward sideto the outward, and adopting an angle ofobservation which corresponds to the nor-mal use of the room or space in question.

The transparency and the colour-impres-sion are influenced by the curvature of theglass because the reflectance of curvedglazing units is always, on account of opti-cal laws, a different reflectance from thatfound in flat glass. Behaviour in terms ofreflectance is influenced by the followingcriteria:� The inherent reflectance of the basic glass� Coatings� Bend radius� Bend-angles of large magnitude

(e. g. more than 90°)� Tangential transitions (see Fig. 7)� Glass thicknessIt is recommended that sample panes bemade, so as to get an initial impression ofthe visual quality and optical effect.

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9.0 Tolerances

The following tolerances apply to cylindri-cally curved glass. The tolerances listed inTable 1 have been established for a maxi-mum edge-length of 4000 mm and a maxi-mum bend-angle of 90°.

In the case of dimensions which exceedthese, the manufacturer should be consul-ted. The tolerances cited are to be appliedto all types of edgework. The quality of theedgework is, at a minimum, arrissed. All ot-her types of edgework are to be agreed inwriting before the awarding of the contract.

For special applications, e. g. in ship- andboat-building, as yacht glass or in furniture-making, the tolerances are to be agreedwith the manufacturer.

All indicated tolerances refer to the glassedges.


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Glass thickness CA CT/CHS CL /CLS* Double CIG(T)

Arc (A) / Height (L) ≤ 2000 mm ≤ 12 mm +/- 2 +/- 2 +/- 2 +/- 2 mm

Arc (A) / Height (L) ≤ 2000 mm > 12mm +/- 3 +/- 3 +/- 3 +/- 3 mm

Arc (A) / Height (L) > 2000 mm ≤ 12 mm +/- 3 +/- 3 +/- 3 +/- 3 mm

Arc (A) / Height (L) > 2000 mm > 12mm +/- 4 +/- 4 +/- 4 +/- 4 mm

+/- 3 mm/m +/- 3 mm/m

Shape Accuracy (PC)** - Absolute value: min. 2 mm, Absolute value: min. 2 mm,max. 4 mm max. 5 mm

Straightness of upper edge (RB) ≤ 12 mm +/- 2 +/- 2 +/- 2 +/- 2 mm per rm.

Edge straightness deviation (RB) > 12 mm +/- 3 +/- 3 +/- 3 +/- 3 mm per rm.

Twist deviation (V) *** - +/- 3 +/- 3 +/- 3 +/- 3 mm per rm.

Displacement (d)**** ≤ 5 m² - - - +/- 2 +/- 3 mm

Displacement (d)**** > 5 m² - - - +/- 3 +/- 4 mm

Position of drill-hole - - EN 12150 EN 12150 - mm

Glass thickness tolerance - EN 572 EN 572 - - mm

* In the case of CL/CLS the glass thickness is the sum of the individual glass thicknesses, not counting the interlayer.The tolerances are valid for CL/CLS made from annealed float glass, thermally toughened glass (TG) or heat-strengthened glass (HSG).

** Curved glass must always be expected to display tangential transitions, along with bulges of the arc-shaped edges.

*** By reference to the longest edges of the glazing unit.

**** By reference to the upper edge and arc-shaped edge; the values stated here are valid for all types of edgework;the proper offset for drill-holes in CL and CLS is worked out with reference to this tolerance.

Table 1: Tolerances


Local bowIt is not necessarily possible to carry overthe values cited in the product standardsfor flat fully-toughened glass and flat heat-strengthened glass and make them applyto curved glass, since said values dependon, among other factors, glass size, geo-metry, and glass thicknesses. In individualcases, these tolerances are to be discus-sed and agreed with the manufacturer.

Shape accuracy (PC)The term “trueness to contour” designatesthe degree of precision of a bend. All theedges of the contour are subject to a 3mm inward or outward offset. The actualbend-contour must not deviate in any gre-ater measure than this from the ideal con-tour. (see Fig. 2). When testing truenessto contour, it is permissible to average outthe glass within this ideal contour


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Fig. 2: Schematic representation of shape accuracy (PC)

Fig. 3: Straightness of Upper Edge (RB)

PC

Glass thickness

RB

PC

1000mm


Twist deviation (V)The term “torsion” describes the exact-ness of the parallelity of the upper edgesin the glass’s bent condition. In curvedglass, torsion must not exceed +/- 3 mmper running metre (straight edge) (seeFig. 4). To this end, the glass must belaid with its upper edges on a flat surfa-ce and tested (convex position or N posi-tion).

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Fig. 5: Displacement in CL/CLS (d)

Fig. 6: Displacement in CIG (d)

Fig. 4: Schematic representation of twist deviation (V)

A, H

A, H

A, H

d

d

d

d

V

1000 mm



Tangential transitionsA tangent is a straight line which touchesa given curve at one particular point. Atangent is perpendicular to that radiuswith which it is associated.If there were not a tangential transitionthe glass would have a kink in it! This is,indeed, technically possible, but not to berecommended. At the point of the kinkthere emerge higher tolerances than at apoint of tangential transition.


12

Fig. 7: Tangential transitions

Centre point of arc

Centre point of arc

90°

< 90°

With tangential transition

Without tangential transition

Tangent

R

R

RR


13

10.0 Dimensioning

10.1 Peculiarities in structural physicsas compared to flat glass panes

Shell load-bearing capacity of curved glassThe calculation of stress and deformationphenomena in curved glass panels is tobe conducted by means of an appropriatefinite element model according to the“theory of shells” in structural mechanics.This model must be capable of represen-ting the geometry of the pane, in particu-lar its curvature.

A simplified calculation of the curvedglass panels as if it were a matter of flatglass panels will lead necessarily to falsestress and deformation values.

When establishing the necessary glassthickness, the curvature can sometimes,depending on the positioning conditionsin the case of single-glazing units (monoli-thic glass, LG, and LSG), prove advanta-geous, since the shell load-bearing capa-city can be taken into account.

10.2 Climatic pressures applyingto curved insulating glassIn the case of insulating glass units it iscompulsorily necessary to take the curva-ture of the glass into account, since insu-lating glass’s higher resistance to bendingcan result in extremely heavy climaticpressures (inner load). The advantage gai-ned in terms of the shell load-bearing ca-pacity of curved single glazing units is notso great when they are constructed in theform of insulating glass units as it is intheir application as single glazing.

A proof in terms of structural engineeringof these high levels of pressure and stressis only possible where a value for theglass curvature has been arrived at andcan be used in the calculation. The clima-tic pressures in question may not be de-termined on the basis of the “TechnicalRegulations for the Use of Glazing with Li-near Supports” (“TRLV”) [1], since theseclimatic loads are derived from plate theo-ry as this applies to flat panes of glass.

Particularly close attention is to be paid tothe dimensioning of bent insulating glassunits with flat extension pieces, since theflat area of the whole is significantly moreflexible than the bent area.

Due to the greater climatic pressures affe-cting curved insulating glass units , the lo-ad that is placed on the edge seal of thisglass is greater, as compared to flat insu-lating glass. The edge seal is to be con-structed in a way that takes account ofthis fact. This in turn can affect the widthof the edge seal or the requisite glass bi-te. All this is to be taken into account alre-ady at the stage of planning and design.

10.3 Bases of calculation

Characteristic bending tensile strengthsFor flat glass panes, the characteristicbending tensile strengths are establishedin the product standards or National Tech-nical Approvals (e.g. for HSG). At the pre-sent time, the use of curved glass panesis only possible where an Exceptional Ap-proval has been granted or where the pro-duct used is the subject of a NationalTechnical Approval. If tolerances in res-pect of permissible stress levels are alrea-dy defined in a National Technical Appro-val, these can be used directly in workingout dimensioning. If the values listed arecharacteristic values, then the manner ofproceeding should be the same as whenusing values derived from experiments.

Where a curved glass without NationalTechnical Approval is used, there shouldbe confirmed, in consultation and coordi-nation with the competent Senior BuildingSupervisory Authority of the German fede-ral state concerned, those characteristicbending tensile strengths which are citedby the respective manufacturer and whichform the basis of the dimensioning. Thesebending tensile strengths should havebeen established beforehand by a testinginstitute.

The basis for this is a well-founded statisti-cal evaluation of experiments with a cor-respondingly sufficiently large number oftest objects (e.g. 20 objects).A description of how the experiments wereconducted is given in [4] and [5] .




14

The experiments should be conductedwith test pieces constituted in such a waythat the results they yield can be transfer-red to the construction in question.

Account should be taken, already duringthe phase of planning of time and calcula-tion of costs, of the effort and expenditurerequired to plan and conduct these experi-ments. For a provisional dimensioning the-re can be used the characteristic bendingtensile strengths fk given in Table 2. Onthe basis of the general safety conceptoutlined in the “Technical Regulations forthe Use of Glazing with Linear Supports”(TRLV) [1] the permissible bending tensilestrengths can be established, with a cer-tain safety factor, in reliance on the TRLV,provided that coordination with and adap-tation of the latter are conducted in accor-dance with professional engineering stan-dards.

In individual cases, this procedure is to becoordinated with the competent SeniorBuilding Supervisory Authority of the Ger-man federal state concerned.

10.4 Fitness for use

10.4.1 Limitation of the degree ofdeflection of the glazingDeflection in the curved glazing is to berestricted in such a manner as to ensurethat any slipping of the glass out of its sillboards is safely prevented and that thecriteria for fitness-for-use are fulfilled.

10.4.2 Limitation of the degree ofdeflection in the substructureStandards and specifications applicableto flat glazing units are not to be carriedover and applied to curved glazing units,since minimal deformations of the sub-structure tend to exert significantly greater

effects upon curved panes than they doupon comparable flat-glass panes. For thisreason, the behaviour of the substructuremust, when carrying out dimensioning workfrom a structural-engineering perspective,quite definitely be taken into account.

11.0 Storage and transport

The glazing units must, in accordance withtheir geometry, be stored and transportedin an upright position which will result inthe least amount of stress and strainbeing placed on them. The manufacturer’sspecifications are to be complied with.

The materials that they are placed on, orthat are used to support them and keepthem from tipping over, must always besuch as not to cause any damage to theedge seal of the CIGs or to the glass itself.

The glazing units must also never, noteven for a short period, be set down on ahard surface, such as for example a con-crete or stone floor.

During handling and setting in place, caremust be taken to ensure that the edge se-al and the glass edges are not damaged,since even very slight damage to the ed-

ges of the panes, which might not be im-mediately noticeable, can nonetheless bethe cause of pane breakage at some laterpoint in time.

As a general principle, glass units must beprotected against damaging chemical orphysical effects on site. All glass unitsmust be protected against prolonged ex-posure to moisture or solar radiation bymeans of a suitable full-size cover.

The transporting of heavy glazing unitsmust be conducted in such a manner thatall the individual panes are held steadilyand evenly in place. The lifting, for a shorttime, of the glazing unit by just a singleone of its constituent panes, in order tohandle it or set it in its place, is possible,but should be effected with the aid of ap-propriate equipment.

When transporting CIGs to, or through,high altitudes above sea level the use of apressure compensation valve may be ne-cessary. This is because of the possiblepressure difference between the cavity ofthe CIG and that of the ambient environ-ment (this depends on the height abovesea level of the place where the IGU wasmanufactured). This is to be stated at thetime of placing the order with the glassmanufacturer.

Glass Type fk (N/mm²)Glass surface Glass edge

Curved float glass (CA) 40 32

Curved heat-strengthened glass (CHS) 55 55

Curved thermally toughened safety glass (CT) 105 105

Table 2: Typical Bending Tensile Strengths, Cited from (4)


15

12.0 Glazing

12.1 General remarksThe glazing guidelines formulated for flatglazing units are, in principle, also appli-cable to curved glazing units. However, gi-ven the special behaviour characteristic ofcurved glass, the supplementary instru-ctions and indications provided by themanufacturer are also to be complied with.

12.2 Instructions in respect of designand construction mattersOn account of its high degree of stiffnessthe tolerances of curved glass (see Ch. 9)must definitely be taken into account alre-ady at the time of its design and constru-ction, so as to ensure that the glass canbe positioned and set in place without anyforcing or straining.It is also necessary that the glass be sto-red in a manner which is likewise free ofall forcing or straining, so as to avoidglass breakage or, in the case where theglass being used is a curved IGUs, over-straining of the edge seal. In addition, sto-rage which does not take care to avoidforcing and straining may lead to impair-ment of the glass’s visual qualitiy.The substructure must satisfy the specialrequirements bearing on curved glazingunits. Necessary here are sufficiently well-dimensioned rebates in frame constru-ctions and façade constructions.

12.3 Necessary rebate widthThe minimum required rebate width = (to-tal glass thickness + tolerance derivedfrom trueness to contour) + 6 mm.Glass thicknesses are to be taken intoaccount in the form of nominal dimen-sions. In addition to this, the specifica-tions stated in DIN 18545 [6] are also tobe complied with.

Furthermore, the tolerances relative to thesubstructure are also to be taken intoaccount.

It is recommended that the window andfaçade systems be executed using thewet-sealing method.

The manufacturers of curved glass shouldbe drawn into the planning process earlyon, so as to allow the special features andproperties of curved glass units to be ta-ken into consideration from the designand construction viewpoint. This is especi-ally necessary also for the application ofcurved glass in the area of structural glassengineering.

13.0 Blocking

The basic principles involved in the pla-cing of glazing blocks are described in [7].The system of glazing blocks must con-duct the dead load of the glazing unit sa-fely into the substructure. The glazingunits do not, as a rule, themselves takeon the task of bearing loads originatingwithin the structure. In the case where it isintended that the glazing units should in-deed take on the function of bearing lo-ads or weights originating in the structure,this must be taken into account already atthe stage of planning out the basic stru-ctural-engineering principles that will ap-ply in the given project. The glass manufa-cturer or system provider should also becontacted and consulted here.

In all systems using curved glass unitsboth a circulating water vapour pressureequalization and a permanent drainagemust be ensured. Glazing block place-ment is itself a task which belongs already

to the planning stage and should be car-ried out before the execution of the as-sembly work.

The location block placed in the middle(see Fig. 8) serves to stabilize the glazingunit and to prevent its tipping over duringthe process of assembly. Once the glazingunit has been fixed in place, this locationblock must be removed again.

Curved single glazing or insulating glazingunits installed in a vertical position musthave their glazing blocks placed in the sa-me manner as these are placed in the ca-se of flat panes. In System 1 the weight ofthe glass is conducted away onto the lo-wer curved glass edge, via the settingblocks, into the frame structure and thenon into the retaining structure (see Fig. 8).

In the case where installation positionsdeviate from the one just described – forexample, in the case of glazing installedat a sloped or inclined angle – the manu-facturer or planner should be contacted.In System 2 the effects of glass-weightand wind-load are exerted in a mannerthat is spread out along the glass edge(see Fig. 9).

This must be taken especially intoaccount when setting up the system ofsupports and bearings. The constructionsdescribed above represent only a selec-tion from among a series of possible situ-ations. In cases where other profiles or sec-tion are set into the insulating glass edgeseal – as, for example, in the case ofspherical bending – or where the glass isapplied as part of structural glazing, themanufacturer must in every case be con-tacted and consulted.



For curved glazing units, the following re-commendations in respect of glazingblock placement are also made:The placing of setting blocks must be car-ried out in such a manner that the glazingunit is in a state of equilibrium and can-not tip over. This means that the settingblocks must be arranged in such a waythat a line connecting the central points ofthe two glazing blocks cuts across the lineof the centre of gravity of the glazing. Atthis point of maximum load the dead loadof the glazing unit is conducted away intothe surrounding structure.

Positioning is dependent on geometry, si-ze, and glass construction. The position ofthe setting blocks must be taken intoaccount in the dimensioning of the sub-structure.

13.1 DefinitionsT = Setting block, conducts away theweight of the glazing unit. Blocks consis-ting of elastic material of approx. 60-80Shore A hardness and a load-capablesubstrate.

D = Location block, ensures that a distan-ce is maintained between glass-edge andrebate base. Blocks likewise consisting ofelastic material with approx. 60-80 ShoreA hardness. The weight is taken over bythe setting blocks alone. The distancemaintained from the corner of the glassshould correspond to the regular distanceof 100 mm.


16

T

T

D

T

T

D

Fig. 9: Arrangement of glazing-block placement according to System 2System 2

T

T

D

D

D

System 1Fig. 8: Arrangement of glazing-block placement according to System 1


14.0 Measurement

So as to manufacture the end-product wis-hed for, it is very important in the case ofcurved glass that a very precise measure-ment be carried out and that there be sta-ted information of various sorts bearingon dimensions etc. In the case of cylindri-cally curved glass units, regardless of thetype of glass planned for, the parameterslisted below must necessarily be stated,so as to allow the determination of a tech-nically feasible and economically advanta-geous solution.

This involves the stating of at least two ofthe values listed below:� Arc� Bend radius� Rise (inner or outer)� Angle.In addition, there should be stated thelength of the straight edge as well as thenumber of panes.

15.0 Literature

[1] TRLV:2006-08 - Technical Regulationsfor the Use of Glazing with Linear Sup-ports. Deutsches Institut für Bautech-nik, Berlin

[2] TRAV:2003-01 - Technical Regulationsfor the Use of Fall-Proof Glazing. Deut-sches Institut für Bautechnik, Berlin

[3] Guideline to Assess the Visible Quali-ty of Glass in Buildings. Bundesver-band Flachglas e.V., Troisdorf, 05/2009

[4] Bucak, O., Feldmann, M., Kasper, R.,Bues, M.Illguth, M.: Das Bauprodukt“warm gebogenes Glas“ – Prüfverfah-ren, Festigkeiten und Qualitätssiche-rung. (The building product “Thermallycurved glass”: testing procedures,consistencies, and quality assurance)Stahlbau Spezial (2009) – (SpecialEdition on Steel Constructions (2009),pps. 23 - 28

[5] Ensslen, F., Schneider, J., Schula, S.:Produktion, Eigenschaften und Trag-verhalten von thermisch gebogenenFloatgläsern für das Bauwesen – Erst-prüfung und werkseigene Produktions-kontrolle im Rahmen des Zulassungs-verfahrens (Production, properties,

and load-bearing behaviour of ther-mally curved float glass for the buil-ding industry – Initial testing and pro-duction-site self-supervision in thecontext of Official Approval Procedu-res). Stahlbau Spezial (2010) –(Special Edition on Steel Constru-ctions (2009)), pps. 46 - 51

[6] DIN 18545: Sealing of glazing unitswith sealants – Part 1: Requirementswith respect to glass rebates. Beuth-Verlag, Berlin, 02/1992

[7] Technical Directive No. 3 of the Insti-tute of Glazing: Blocking of GlazingUnits. Verlagsanstalt HandwerkGmbH, Düsseldorf, 7th Edition, 2009

17

L

AA

A

Cai

Ri

Ra

Re

F

a

T

Fig. 10: Measurement

A = Outer arcRa = Radius to middle of pane (= neutral arc)Ri = Inner radiusRe = PitchF = RiseCai = Chord (internal)� = AngleT = Glass thickness



16.0 Contact Persons in theVarious German Federal Sta-tes for the Acquisition of anExceptional Approval (ZiE)Last updated: 08.12.2010

Baden-WürttembergDipl.-Ing. Steffen SchneiderRegierungspräsidium TübingenReferat 27, Landesstelle für BautechnikKonrad-Adenauer-Str. 20, 72072 TübingenTel: +49 (0) 711 [email protected]

BayernBOR Dipl.-Ing. Hubertus WambsganzOberste Baubehörde im BayerischenStaatsministerium des InnernFranz-Josef-Strauß-Ring 480539 MünchenTel: +49 (0) 89 2192 [email protected]

BerlinDr.-Ing. Gerhard EspichSenatsverwaltung für StadtentwicklungWürttembergische Straße 610707 BerlinTel: +49 (0) 30 [email protected]

BrandenburgDr.-Ing. Frank GellnerLandesamt für Bauen und VerkehrAußenstelle CottbusGulbener Straße 24, 03046 CottbusTel: +49 (0) 3342 4266 [email protected]

Dipl.-Ing. Türk SchellenbergLandesamt für Bauen und VerkehrAußenstelle CottbusGulbener Straße 24, 03046 CottbusTel:+49 (0) 3342 4266 [email protected]

BremenDipl.-Ing. Peter HabedankDer Senator für Umwelt, Bau,Verkehr und EuropaContrescarpe 72, 28195 BremenTel: +49 (0) 421 [email protected]

HamburgHerr Oliver BruneBehörde für Stadtentwicklung und UmweltStadthausbrücke 8, 20355 HamburgTel: +49 (0) 40 42840 - [email protected]

Frau Martina MenzeBehörde für Stadtentwicklung und UmweltStadthausbrücke 8, 20355 HamburgTel: +49 (0) 40 42840 - [email protected]

Herr Martin RückerBehörde für Stadtentwicklung und UmweltStadthausbrücke 8, 20355 HamburgTel: +49 (0) 40 42840 - [email protected]

HessenBD Dr.-Ing. Dieter PohlmannHessisches Ministerium für Wirtschaft,Verkehr und LandesentwicklungKaiser-Friedrich-Ring 7565185 WiesbadenTel: +49 (0) 611 [email protected]

Dipl.-Ing. Brigitte SchneiderHessisches Ministerium für Wirtschaft,Verkehr und LandesentwicklungKaiser-Friedrich-Ring 7565185 WiesbadenTel: +49 (0) 611 [email protected]


Mecklenburg-VorpommernZ. Zt. N NMinisterium für Verkehr, Bau und Landes-entwicklung Mecklenburg-VorpommernSchloßstraße 6-8, 19053 SchwerinTel: +49 (0) 385 588-0 (Zentrale)[email protected]

NiedersachsenHerr Dipl.-Ing. Holger WinklerNiedersächsisches Ministeriumfür Soziales, Frauen, Familie,Gesundheit und IntegrationHinrich-Wilhelm-Kopf-Platz 230159 HannoverTel: +49 (0) 511 120 [email protected]

Nordrhein-WestfalenDipl.-Ing. Andreas PlietzMinisterium für Wirtschaft, Energie,Bauen, Wohnen und Verkehrdes Landes Nordrhein-WestfalenReferat X A 4 Bautechnik, BauphysikJürgensplatz 1, 40219 DüsseldorfTel: +49 (0) 211 [email protected]

Rheinland-PfalzDipl.-Ing. Hermann HoegnerMinisterium der Finanzendes Landes Rheinland-PfalzKaiser-Friedrich-Straße 555116 MainzTel: +49 (0) 6131 [email protected]

SaarlandDipl.-Ing. Robert BeckerMinisterium für Umwelt, Energieund Verkehr- Oberste Bauaufsicht -Keplerstraße 18, 66117 SaarbrückenTel: +49 (0) 681 [email protected]

18


SachsenHerr Frank Christian KutzerLandesstelle für BautechnikBraustraße 2, 04013 LeipzigTel: +49 (0) 341 [email protected]

Sachsen-AnhaltHerr Rolf SchneiderMinisterium für Landesentwicklung undVerkehr des Landes Sachsen-AnhaltTurmschanzenstraße 3039114 MagdeburgTel: +49 (0) 391 [email protected]

Schleswig-HolsteinHerr Gerhard BehrendtInnenministerium des LandesSchleswig-HolsteinDüsternbrooker Weg 9224105 KielTel: +49 (0) 431 [email protected]

ThüringenDr.-Ing. Helmut BietzThüringer Ministerium für Bau,Landesentwicklung und VerkehrAbteilung 2Steigerstraße 24, 99096 ErfurtTel: +49 (0) 361 37-91 [email protected]

Fachliche Anfragen/Beiträge:Herr Reinhard SommerThüringer LandesverwaltungsamtWeimarplatz 4, 99423 WeimarTel: +49 (0) 361 [email protected]

17.0 Standards, regulationsand directives

EN ISO 140- 3: Acoustics – Measurementof sound insulation in buildings and inbuilding components – Part 3: laboratorymeasurements of airborne sound insula-tion of building components

EN 356: Glass in building – security gla-zing – testing and classification of resis-tance against manual attack

EN 357: Glass in building – Fire resistantglazed elements with transparent or trans-lucent glass products – Classification of fi-re resistance.

EN 410: Glass in building – Determinationof luminous and solar characteristics ofglazing

EN 572: Glass in building – Basic sodalime silicate glass products

EN 673: Glass in building – Determinationof thermal transmittance (U value) – Cal-culation method.

EN ISO 717-1: Acoustics – Rating of soundinsulation in buildings and of building ele-ments – Part 1: Airborne sound insulation

DIN 1055: Actions on structures

EN 1063: Glass in building – Security gla-zing – bullet-resistant glazing – classifica-tion and test method

EN 1096: Glass in building – coatedglass, high-rise construction – sealants forjoints – classification and requirementsfor sealant masses

EN 12150: Glass in building – thermallytoughened soda lime silicate safety glass

EN 1863: Glass in buildings – heat streng-thened soda lime silicate glass

EN ISO 12543: Glass in building – lami-nated glass and laminated safety glass

EN 14179: Glass in buildings – heatsoaked thermally toughened soda limesilicate safety glass

EN 14449: Glass in building – Laminatedglass and laminated safety glass

DIN 18008: Glass in building – designand construction rules

DIN 18032: Sport halls – halls for gym-nastics and games

DIN 18361: Glazing works

EN 20140: Acoustics – measurement ofsound insulation in buildings and in buil-ding components

BF (Bundesverband Flachglas) guidelines� Guideline to assess the visible quality

of glass in buildings� Guideline to asses the visible quality

of enameled and screen printed glasses� Compatibility of materials as relating

to insulating glass and associatedtopics

� Compass for sealant-bonded windows� Guidelines for the handling of multi-

pane insulating glass units

Fact-sheets from the association: Fen-ster und Fassade e.V.� Uniformity of colour in transparent

glass units in the building industry� Installation recommendations for

safety and security glass in thebuilding industry

� Glass joints and all-glass corners inwindows and facades

BF-Merkblatt 009 / 2011

19



Technical Guidelines of the FederalAssociation of German Glazing Guilds,HadamarPamphlet 1 Sealants for glazing units

and adjacent jointsPamphlet 3 Glazing-block placement in

glazing unitsPamphlet 8 Making glass proof against

danger to the visiting publicPamphlet 9 Principles for the visual

testing and evaluation ofglazing in buildings

Pamphlet 10 Technical concepts fromthe area of glass handicraft

Pamphlet 14 Glass in building – classifi-cation of glass products

Pamphlet 17 Glazing with insulating glassPamphlet 18 Fall-proof glazing according

to the stipulations of the TRAVPamphlet 19 Glazing with linear supports

and secured at individual pointsPamphlet 20 Guidelines for the assembly

of windows and house doors

Fact-Sheets from the Federal GermanStatutory Accident Insurance� GUV-SI 8027 More safety in cases of

glass breakage� GUV-VS 2 Nurseries and day-care

centres� BGI/GUV-I 669 Glass doors, glass walls� GUV-VS 1 School buildings� GUV-VC 9 Cash offices

18.0 Further reading

� Runkel, H.-W., Scheideler, E.: Geboge-nes Glas – Herstellung und Statik.(Curved glass – Manufacture and struc-tural-engineering properties). Sonder-druck aus Glaswelt 6 und 8/2000(Special Edition reprinted from Glas-welt 6 und 8/2000), Gentner-Verlag,Stuttgart


www.bundesverband-flachglas.de

This bulletin was produced by: Bundesverband Flachglas e.V., Mülheimer Straße 1 · D-53840 Troisdorf

Participating Firms: Döring Glas GmbH & Co KG, Cricursa, Edgetech, HS München, Labor für Stahl- und Leichtmetallbau, FINIGLAS Veredelungs GmbH, Flachglas Wernberg

GmbH, Flintermann, Freericks Glasveredelung, glasid ag, Gretsch-Unitas GmbH, Guardian Thalheim GmbH, Hero Glas, Interpane Glasindustrie AG, IB KRAMER - Tragwerksplanung

FEM-Berechnungen, RWTH Aachen, Ingenieurbüro Scheideler, Technische Beratung, Statik & Dynamik, SCHOTT, Semcoglas Holding GmbH, Tambest, WMG Group Cork / Irland

© Bundesverband Flachglas e. V. Permission to reprint material from this fact-sheet will be gladly given where formal request is made. Without our explicit consent,

however, it is not permitted to reprint or reproduce this text or any part of same. No claims or liabilities of any sort may be derived from the fact of its publication.

� Feldmeier, F.: Klimabelastung und Last-verteilung bei Isolierglas (ClimaticStress and load distribution in insula-ting glass). Stahlbau 75 (2006), Vol.6, Ernst & Sohn, Berlin

� Bucak, 0., Schuler C.: Curved glass.Ch. 6, Glas im konstruktiven Ingenieur-bau (Glass in civil-engineering con-struction) Stahlbau Yearbook (2008),Beuth-Verlag, Berlin

� Elstner, M., Schäfer, S.: Herausforde-rung gebogene Gläser (The challengeof curved glass units). Glas + Rahmen,Verlagsanstalt Handwerk GmbH,Düsseldorf, 09/2010

� Ensslen, F.: Gebogenes Glas – Heraus-forderungen für Anwender (Curvedglass – challenges for the user) Glas-welt, Genter-Verlag, Stuttgart, 10/2010

Bundesverband Flachglas e.V.

Mülheimer Straße 1

53840 Troisdorf

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