Different types of glass

Clear (annealed) float glass

Clear float glass is a basic glass that is most commonly used in windows and doors. Clear float glass provides high transmission of light. Float glass can be clear or coloured and is produced in large sheets. It can be modified as outlined below to improve its qualities.

Toughened safety glass

Toughened safety glass is up to five times stronger than clear float glass. It offers the highest resistance to impact and is therefore commonly used in glass doors. The toughening process reduces the risk of thermal breakage.

Laminated safety glass

Laminated glass is a popular choice for residential and commercial windows and doors. It is made up of two or more layers of glass permanently bonded together by heat and pressure with a poly vinyl butyral (PVB) interlayer. This layer holds the glass panels together so that if broken, the glass remains intact. The laminated layer can also assist in blocking out up to 99% of UV rays. This makes laminated glass a very safe option for glass windows and doors. Laminated glass also has good sound and insulation properties and is available in clear, tinted, reflective and low-e glass.

Tinted glass

Tinted glass is used primarily for solar control, meaning that it reduces direct heat energy from the sun coming in through your windows. Tinted glass also reduces glare which is why it is commonly seen in car windows. The most common colours in tinted glass are grey, bronze, green and blue.

Reflective glass

Reflective glass has a special metallic coating that limits or restricts people from looking inside your home or office. However, the coating does not stop those inside from looking out. The benefits of reflective glass are that it allows natural light into a building but reduces any glare. Reflective glass can also be made up into IGUs combined with low-e glass for even greater thermal and energy efficiency. Reflective glass comes in a wide range of colours including grey, bronze, green and blue.

Low-e glass

The 'e' in low-e glass refers to emissivity. Emissivity is the ability of a material or surface to radiate heat/energy. Low-e glass therefore refers to a glass surface which minimises the amount of solar heat gain to pass through. This is achieved through the application of a special coating that is made of a microscopic, transparent metal or metal oxide on one surface of the glass. This coating minimises UV light and heat passing through the glass, but does not limit the amount of visible light. Low-e glass improves thermal insulation and therefore helps reduce heating and energy costs. Low-e glass is used on all double glazed units.

Low-e glass is available annealed, toughened and laminated.

For more help with selecting the right glass for your windows and doors, contact the expert contributor.