Glossary – our knowledge from A to Z

This type of glazing prevents the spread of smoke and flames, but cannot prevent the passage of heat radiation. It remains transparent in the event of fire.

The total energy transmittance (g-value) is the sum of the direct transmission due to solar radiation and the inward heat emissions due to radiation and convection. Double glazing made from clear glass has a g-value of approx. 0.8.

Gemeinsamer Ausschuss Elektronik im Bauwesen (Joint Committee for Electronics in Building). See: www.gaeb.de.

Electronic file for exchanging specifications and quotations according to standards laid down by the GAEB.

Electronic data format for exchanging specifications and quotations.

This is a trade name for strip or sheet steel with an anti-corrosion surface finish. The finish in the form of an aluminium-zinc alloy is applied to the surface of the steel in a hot-dip process. The zinc melt normally contains 5 % aluminium and approx. 0.1 % so-called misch metal.

This is a trade name for strip or sheet steel whose surface has been coated with a special aluminium-zinc alloy. To apply the coating, the steel is dipped in a bath containing 55 % aluminium, 43.5 % zinc and 1.5 % silicon.

This type of corrosion occurs when different metals are in contact in the presence of a corrosive medium. In all cases the less noble metal corrodes.

The application of a thin layer of zinc to steel to protect it against corrosion.

When hot-dip galvanised strip or sheet steel is annealed following galvanising (at temperatures above the melting point of zinc), the resulting product is known as galvanneal; the process is called galvannealing.

A method of glazing without silicone. Instead, preformed sealing profiles are used, their particular form depending on the system. Also known as gasket or dry gasket glazing.

These tolerances apply to dimensions for which no specific tolerances are specified (untoleranced dimensions). They are divided into nominal size ranges and tolerance classes.

Small-format insulating glass units, like those used for Georgian bar insulating glass windows, are subjected to higher physical loads than large-format insulating glass units, which can compensate for the bowing and dishing via the elasticity of the pane of glass itself.

Abbreviation for glass-fibre reinforced plastic. GFRP is a fibre-plastics composite made from a synthetic material (e.g. polyester resin, epoxy resin or polyamide) and glass fibres. It is colloquially referred to as fibreglass. With the help of GFRP, seele can realise unusual contours in the form of panels (e.g. Unilever House in London).

Glass is an inorganic product made from various molten raw materials and upon cooling does not crystallise, but rather gradually solidifies. In thermodynamic terms, glass is regarded as a frozen, supercooled liquid.

The word glass is derived from the Germanic word glasa. Glass is one of the oldest materials known to humankind, but some of the issues regarding its atomic composition and structure have still not been fully resolved.

This is a balustrade with an infill panel of glass or acrylic sheet. The handrail can be made from stainless steel, wood or aluminium. The glass is often fixed in vertical posts at the sides, but can also be fixed at the base.

This is a method for cleaning and also finishing surfaces. It is used for stripping paint and similar coatings, also for removing welding or soldering slag. This method is also very good for removing temper colours and layers of oxide from non-ferrous metals, stainless steel, cast iron or cast aluminium.

A (mostly) horizontal glass component that can accommodate shear forces and bending moments. Experimental setups have resulted in enormous load-carrying capacities over spans of several metres. Glass beams ensure maximum transparency for roof glazing. Their use as a secondary structure results in enhanced requirements for the residual loadbearing capacity.

A glass blind is an erroneous name for a blind that is fitted between the panes of an insulating glass unit. Such a blind is not made of glass, of course. This is in contrast to glass blinds in furniture, where roller shutters or louvre blinds can be fitted to various kitchen cupboards.

This is generally a hollow glass unit made from two open, pressed shells fused together. The two outer surfaces may be smooth or textured. Glass blocks are available in various formats and colours.

The traditional glass block is made from pressed glass. Glass blocks can be used to construct transparent, translucent, straight or curving walls. seele has redefined the glass block by laminating individual panes of sheet glass. The use of coloured plastic sheets, sandblasting methods, etc. enables a variety of effects to be achieved.

This material is used for producing special suspended floor elements. It is a form of construction in which glass is placed in a frame of in situ or precast concrete and permanently connected to the concrete.

Glass is a brittle material and is characterised by the fact that it breaks directly when overloaded. Unlike, for example, metals, it has no yield point.

The glass bridge designed by seele consists of 4 mm thick bent glass panes with a total thickness of just 3.7 cm for the complete glass element. The highly transparent, curved bridge of cold-formed glass with a span of 7 m weighs 1.7 t in total and can carry a load of up to 7.2 t.

Glass ceramics are produced in a glass technology process and initially solidify on cooling to form glass. Subsequent heat treatment transforms this glass into an essentially crystalline material. Glass ceramics exhibit properties that differ from those of the glass from which it was made.

The removal of a coating from a pane of glass in the vicinity of the edge seal. One reason for this is to ensure a reliable bond. Also known as edge deletion.

The majority of types of glass are produced with further additives in order to influence certain properties, e.g. the colour of the glass. Minute quantities (e.g. 0.1 %) of metals are added to the melt to colour the glass. Gold and silver are the metals used most frequently.

This begins with the leaching of oxides from diverse elements, e.g. sodium, potassium, calcium, barium or boron. The physical properties of the material therefore change at the places affected. A layer of gel forms which reacts with ions from the active substance to form an opaque coating.

A tool for cutting glass. Actually, this term is erroneous because the glass is only scored and then snapped. In the past, a diamond was used for scoring, these days a small steel wheel.

The commonest method of cutting glass is to score the surface with a glass cutter and then snap the glass along this line.

The defects caused by the production, the numbers of which are specified in the respective standard for the glass. There are optical and visible defects depending on the type of glass.

A door with a glass door leaf with or without a perimeter frame. Such doors are made from toughened safety glass.

Safety glass is used for frameless all-glass doors. The glass door leaf is highly resistant to breakage and impacts.

This is a special type of hinge for use with glass doors. The (safety) glass of the door must be factory-drilled in order to attach the hinge.

This is a long, thin fibre drawn out of the glass melt.

Abbreviated to GLARE, this is a new type of composite material consisting of many plies each just a few tenths of a millimetre thick. The plies alternate between aluminium and a glass-fibre laminate (glass fibre-reinforced plastic) and are bonded together under pressure.

A mostly vertical, stiffening glass beam element found in façades. It is used to brace a glass façade.

A material made from quartz sand, soda, limestone and dolomite. Glass is a mixture of various silicates and has a large softening range but no fixed melting point. When it cools from its fluid phase it remains plastically deformable down to a temperature of about 500 °C.

We are pretty certain that seele did not create the world’s oldest work of glass (art)! The oldest glass vessel that can be reliably dated is a goblet bearing the name of the Egyptian pharaoh Thutmose III, which was made around 1450 BC.

The microstructure of glass does not permit the use of cutting-type machining operations. Therefore, unlike when working with metal, glass grinding is therefore not a cutting operation, but rather a process that forces and rips out small particles. Glass can only be ground wet.

Glass is a very popular, very common material in modern architecture. Glass hardly ages and requires a little maintenance, apart from cleaning. Filigree architecture thrives on the extensive use of this material. Glass can also satisfy structural requirements to a certain extent.

A tool for moving and lifting panes of glass. The vacuum created by evacuating the air between the suction cup and the flat surface of the glass ensures that the tool remains attached to the glass. Glass lifters are used to tilt, turn and position panes of glass during installation.

We distinguish between float glass and rolled glass production. These days panes of glass are manufactured almost exclusively by means of the float glass method developed in the 1960s. In the technical regulations and standards this type of glass is also referred to as polished plate glass.

A synthetic material in which glass-fibre mats are bonded together by and enclosed in a thermoplastic material.

This comprises various phases. The initial melting of the raw materials (founding) is followed by the homogenisation phase and then the refining phase in which all bubbles are driven off. Finally, there is the cooling phase, in which the material cools ready for further processing.

This is used for producing the glass melt in the manufacture of glass. The raw materials for the glass in the bath are constantly replenished and combine to form the melt. This process can last several days.

Glass is neither combustible nor flammable and therefore cannot give off any smoke. Glass has a homogeneous, smooth surface, is easy to clean and therefore very hygienic. Glass has a very high chemical resistance and withstands the majority of acids and alkalis, is insoluble in water and essentially corrosion-resistant.

Frame for storing and transporting panes of glass or complete window elements upright. Usually fitted to the outside of a vehicle, but can be fitted inside.

A pressed glass product in the form of a clay or concrete roof tile which is used to admit daylight into roof spaces.

This is a glazing element designed to prevent persons falling from a higher to a lower level. Vertical glazing, glass spandrel panels with a continuous handrail and glass balustrades all fall under this definition.

This is a sliding door made of glass, usually without a frame. Such doors can be used wherever a high degree of transparency is desired.

A self-supporting staircase made entirely of glass. Multiple laminated glass panes with SentryGlas® (SG) interlayers are often used here because of their good load-carrying capacity. These form both the primary and secondary structures of the staircase. Metal parts are used only for connecting elements between the panes of glass. SentryGlas® is a trade name of DuPont™.

In order to be able to describe the position of a coating on a surface of an insulating glass unit, the surfaces of the individual panes of glass are numbered consecutively from outside to inside. The outer surface of the outer pane is therefore surface No. 1, the inner surface of the inner pane No. 4 (double glazing) or No. 6 (triple glazing).

Testing a piece of glass under in situ conditions.

The sizing of sheet glass taking into account the dimensions, position, supports and/or fixings and the action effects to which the glass is subjected (e.g. wind pressure, knife-edge loads, etc.).

This is the temperature range (transformation range) within which the mechanical behaviour of glass changes radically.

Glass transporters are specially designed heavy goods vehicles in which the sensitive glass is clamped in place hydraulically. These vehicles enable base glass products with the standard ribbon size to be transported vertically without the need for any special transport permits. Such vehicles can also be used for transporting other large-format panel-type elements.

Subsequent treatments for primary glass products include attaching plastic foils, edge working, engraving, etc.

Made from special tubular glass, the thickness of this component can be varied to suit its purpose. Today, exclusively mechanical methods are used to produce glass tubes by means of horizontal or vertical drawing methods. Glass tubes can be used as loadbearing elements.

This type of construction is generally delicate and lightweight in appearance. Such designs have enabled entire transparent façade areas to be constructed for the first time. Glass-and-steel façades have in the meantime replaced the fenestrate façade for commercial structures.

In a glass-and-steel roof the loads are carried via a trussing effect. The glazing constitutes the upper chord in compression. The lower chord and the infill bars are of steel. This type of construction results in very delicate and transparent roof structures. Special attention must be paid to the residual loadbearing capacity and transfer of loads into the panes of glass.

The large double-leaf façades designed and constructed by seele for Elm Park in Dublin represent a successful combination of timber beams, structural steelwork and aluminium sections. Timber structures can be glazed just as easily as steel or aluminium ones, provided the particular characteristics of timber are taken into account.

A method of producing glass with a blowpipe. This method is still used for producing many coloured and special glasses or for artistic purposes.

seele was awarded this prize at the glasstec trade fair in 2008 for its curved bridge of cold-formed glass with a span of 7 m. The innovative cold-forming method made it possible to bend glass spanning 7 m without the application of heat for the first time.

This is a mixture of lead and tin for lead cames which are used as the frames in leaded lights or for artistic purposes.

The process of installing a glazing element in its supporting construction.

The installation of glass in doors and windows plus the fabrication of independent components such as glass roofs, glass walls, etc., made from glass or plastics.

The glazing bead presses the pane of glass against a linear supporting member. Glazing beads can be nailed, screwed or clipped in place. The advantages of using glazing beads is the fast installation of the glass and its simple removal in the case of repairs. The disadvantage is the visible width of the frame construction.

This is the width of the pane of glass that lies within the clamping construction, e.g. a patent glazing wing. Depending on which standard applies, a minimum glazing edge cover may need to be guaranteed for a certain loading.

Glazing designed to function as part of a circulation zone. Glazing for constant foot traffic must satisfy high demands regarding loadbearing capacity and residual loadbearing capacity. The glass must have a non-slip surface. Thick panes of glass and multiple laminations (to ensure residual loadbearing capacity) are normally required.

Glazing intended for constant foot traffic must be made from laminated safety glass with at least three panes. The uppermost pane may not be taken into account for loadbearing purposes because it is directly exposed to mechanical damage which reduces its strength; it serves only to protect the loadbearing panes below and should be made from toughened safety glass.

Glazing designed to accept loads due to a limited number of specially trained people. One example is roof glazing that is only accessible for cleaning purposes. This glazing does not have to satisfy such stringent requirements as glazing for constant foot traffic.

Insulating glass with louvres in the cavity for redirecting the incoming daylight.

Gasket profiles that are joined at the corners by vulcanisation to form a (normally) rectangular, watertight or rather vapour-tight, corner joint for a glazing element.

This is the size of a piece of float, rolled, plate glass etc. cut from stock or ribbon sizes.

This consists of at least three laminae glued together with the grain (fibres) of each layer parallel. Glued laminated timber is primarily used for engineered timber structures (e.g. roof trusses). Often abbreviated to glulam.

Regarded as the ideal proportion in mathematics and the arts. The ratio is approx.1:1.618. Corresponding subdivisions are regarded as very harmonious and aesthetically pleasing. Also known as golden section or golden mean.

The natural greenish colouring of soda-lime-silica glasses, caused by the small quantities of iron oxide in the raw materials. Green tinge is not a flaw.

This effect ensues when solar radiation enters a room through glazing (windows or roof) and is absorbed by the materials in the room. This can cause the interior to heat up to temperatures well above those of the surroundings.

A lattice structure made up of a (mostly) large number of different individual elements. Expensive and time-consuming production and erection requirements. Special attention must be given to the design of the nodes. Computer-aided manufacturing (CAE) is essential with such complex projects.

A connecting pin with longitudinal grooves in its circumference. Depending on the particular application, these grooves can have different forms: half-length parallel grooves, half-length central parallel grooves, full-length tapered grooves, part-length tapered grooves. The grooves ensure that the pin remains firmly in place even in very smooth holes, even in the case of dismantling.

This is the density of a porous solid based on its volume including the pores.

A high-strength, non-shrink mortar with cement as the binder. Very high-quality grouts exhibit exceptional flowing properties even with a solids-to-water ratio of 10:1 (by weight).

An organisation committed to upholding and improving the quality of coated building components for external use. The GSB quality regulations apply to the coating of building components made from aluminium and steel and its alloys which are used in the building industry.

This prevents persons falling from a higher to a lower level. The uprights (posts) to a guard rail can also help to stiffen the treads of a stair. A guard rail must be able to withstand the lateral load of a person.

Such a heating installation can be fitted in the bottom of a gutter. It ensures that the base of the gutter is always kept clear of ice and snow so that meltwater can drain away unhindered. The self-regulating electrical heating installation is controlled via temperature and/or moisture sensors.

German abbreviation for friction-grip connection (gleitfeste, planmäßig vorgespannte Verbindung). In this type of connection the mating faces between the two components can be used to transfer forces via friction. Friction-group connections always require the application of a preload to the fastener and corresponding pretreatment of the friction faces.

German abbreviation for close-tolerance friction-grip connection with preload (gleitfeste, planmäßig vorgespannte Passverbindung). The load-carrying capacity is higher than that of a standard friction-grip connection without close-tolerance bolt. The application of a preload makes additional retainers superfluous.

A building product made from gypsum, mostly used in the form of plasterboard (GKB) with a layer of cardboard both sides for dry lining or acoustic purposes. The layer of cardboard both sides accommodates tensile forces and gives the board its stability.