Types of Glass used in Building
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Float glass

This is named after the modern process used to create large, thin, flat panels from molten glass which is floated onto a pool of molten metal such as tin. This process produces a very smooth sheet of glass with a highly consistent thickness. Float glass is made of sodium silicate and calcium silicate so, it is also called as soda lime glass. It is clear and flat so, it causes glare. These glasses are available from 2mm to 20mm thickness ranges. They have a weight range of 6 to 36 kg/m2. These are used as shop fronts, public places etc.

Annealed glass
This is a piece of float glass that has been cooled in a slow and controlled manner. The internal stresses within the sheet of glass are reduced by this process making the resulting glass stronger and less likely to break than it would otherwise be. There can be safety concerns using annealed glass as it can break into large jagged shards.

Heat strengthened glass
This is made from a sheet of annealed glass reheated beyond its annealing point of around 1,200ºF and then cooled slowly. Heat strengthened glass may be twice as strong as annealed glass, but may still need to be laminated for use in buildings.

Fully tempered glass
Tempering is the process by which annealed glass is heated in the same way as heat strengthened glass. The glass is cooled more rapidly which allows the internal portion of the glass to remain fluid for longer than the outer surfaces. This means that an equal amount of tensile and compressive stresses are formed across the glass which allows it to become in the order of four times as strong as annealed glass. This is used as a safety glass, as it shatters into small granular pieces rather than sharp shards, reducing the risk of injury.

Heat soaked tempered glass
This is used as a means of testing glass panes that are to be used in safety critical situations, such as a glass railing. Tempered glass panes are heated to a temperature of around 550ºF for a few hours. This causes any unstable nickel sulfide inclusions (imperfections that may cause spontaneous breakage of the pane) to expand disproportionately to the glass, making the glass break.

Laminated glass
Laminated glass is the combination of layers of normal glass. So, it has more weight than normal glass. It has more thickness and is UV proof and soundproof. These are used for aquariums, bridges etc 
Laminated glass is used where glazing must remain intact if it is broken, either for safety or security reasons. It is made by fusing two or more layers of glass with inter-layers of polyvinyl butyral (PVB) through the use of heat and pressure. If it is made using heat strengthened glass, the pane will break into large pieces but will be held in the frame by the PVB inter-layer. If it is made from tempered glass, the sheet may fall out of the frame but will mostly stay together due to the inter-layer.

Wired glass
This is most often used as a fire resistant glass because the wire holds the glass in place if high temperature causes it to break. The wire mesh is better at holding glass in place than the PVB films used in laminated glass.

Low-emissivity (Low-E) glass
The term ‘low-e glass’ is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity so that it reflects, rather than absorbs, long-wave infra-red radiation.

In cooler climates this means that long-wave infra-red radiation that builds up inside a building is reflected by the glass back into the space, rather than being absorbed by the glass and then partially re-radiated to the outside. This reduces heat loss and so the need for artificial heating.

In hotter climates, a low-e coating means that long-wave infra-red radiation outside the building is reflected back out of the building, rather than being absorbed by the glass and then partially re-radiated to the inside. This reduces the heat build-up inside the building and so the need for cooling. In hotter climates, a low-e coating might be used in conjunction with solar-control glass to reduce the amount of short-wave solar radiation entering the building.

The two main types of low-e coating are tin and silver. Tin oxide is applied to the glass at high temperatures to create a very hard and durable low-e coating. Silver coating must be enclosed within the glazing unit so that oxidation doesn’t cause the degradation of the silver over time.

Self-cleaning glass
A transparent coating can be applied to glass during the manufacturing which reacts with the sun’s UV rays to break down dirt and grime which forms on the outside of the windows, and when it rains, the decomposed dirt natural rinses away. The coating has hydrophilic properties which mean it attracts water over its entire surface, avoiding unsightly uneven water marks

Manish Jain Luhadia 
B.Arch (hons.), M.Plan
Email: manish@frontdesk.co.in
Tel: +91 141 6693948
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Messages In This Thread
Types of Glass used in Building - by FDArchitects - 03-18-2014, 06:59 AM
RE: Types of Glass used in Building - by kitty_jiming - 04-16-2014, 12:54 PM
RE: Types of Glass used in Building - by Manish Jain - 09-10-2018, 03:01 PM
RE: Types of Glass used in Building - by sandeep jain - 10-04-2018, 09:12 AM
RE: Types of Glass used in Building - by mehak jain - 10-09-2018, 06:51 AM

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