Named from the production process of using liquid tin to create a perfectly flat surface by floating the glass on top of the hot metal. This is the latest technology for manufacturing the thinner glass available
2mm – used mainly in small to medium picture frames
4mm – the standard specification for most glass,
unless the requirement is for toughened or laminate
Thicker glass becomes too heavy to float on tin, so while it is in its hot state, it is ‘rolled’ to the thickness required
6mm to 20mm plate - this used to be considered safety glass, before laminated and safety glass was invented.
Low Emission glass has been developed as an energy efficient option for domestic and residential installation. It has a metal oxide coating that retains heat generated from within the home, and keeps the cold or summer heat outside. It can be coated with a hard or soft coating, of which the more expensive soft coat is the better performer. The soft coat itself however can show a brown or grey tint and will become damaged with handling. It can therefore only be used in sealed glazed units.
Toughened glass is produced by applying a special treatment to ordinary float glass after it has been cut to size and finished. The treatment involves heating the glass so that it begins to soften (about 620 degrees C) and then rapidly cooling it. This produces a glass which, if broken, breaks into small pieces without sharp edges. The treatment does increase the surface tension of the glass which can cause it to 'explode' if broken; this is more a dramatic effect than hazardous.
It is important to note that the treatment must be applied only after all cutting and processing has been completed, as once 'toughened', any attempt to cut the glass will cause it to shatter.
Toughened glass is ideal for glazed doors, low level windows (for safety) and for tabletops (where it can withstand high temperature associated with cooking pots etc.
Toughened glass is approximately 5 times stronger than its untreated equivalent.
Made from flat glass, this type has a design rolled onto one side during manufacture. It can be used for decorative effect and/or to provide privacy. Patterned glass is available in a range of coloured tints as well as plain.
A variety of pattern designs are available, each pattern normally has an quoted distortion number, from 1 to 5, 1 being very little distortion, 5 being a high level of diffusion.
On external glazing, the patterned side is usually on the inside so that atmospheric dirt can easily be removed from the relatively flat external face.
As the name suggests, laminated glass is made up of a sandwich of two or more sheets of glass (or plastic), bonded together by a flexible, normally transparent material.
If the glass is cracked or broken, the flexible material is designed to hold the glass fragments in place.
The glass used can be any of the other basic types (float, toughened, wired etc.) and they retain their original breaking properties.
Some laminated glass is laminated for other reasons than just keeping any broken glass in place, some provide decorative internal finishes to the glass while others act as fire breaks.
Mirrors are usually made from float glass 4-6mm thick, and silvered on one side. Mirrors are available for use without a surrounding frame, these usually are made from a type of safety glass. Old mirrors, and modern mirrors supplied within a frame, should not be used unframed as any damage to them might cause the glass to shatter dangerously.
During the float glass melt process chemical colorants can be added which tint the colour and increase absorption from the sun. This helps minimise the solar radiation that enters a building, keeping it cooler inside and protecting furnishings from fade. Body tint glass has the added bonus of making a building look unique and contemporary, creating a lasting impression for business HQs. As an example of the colorants used; to create a purple exterior, manganese is added, while pinks and reds can be produced from selenium.
Georgian Wire Polished Plate
Wired glass incorporates a wire mesh (usually about 10mm spacing) in the middle of the glass. Should be glass crack or break, the wire tends to hold the glass together. It is ideal for roofing in such areas as a garage or conservatory where its 'industrial' look is not too unattractive.
Wired glass is generally not considered a Safety glass as the glass still breaks with sharp edges. Wired glass is available as clear or obscured.
There are two types of fire resistant glass which perform with varying degrees of success:
1. Heat transmitting - This incorporates wired glass and reinforced laminated glass which offer protection against flames and inflammable gases, but only for a short while. It does not prevent heat being transferred to the other side of the glass, so it will be hot to touch.
2. Fire insulating - This glass is capable of a longer containment period of flames, gases and smoke, and also prevents heat transmission to the other side of the glass.