Basic Types of Glass Regularly Used in Construction – Bishop Ltd

There are various forms of flat glass (also known as float glass) used in the construction industry, each for a different purpose. Glass in its more basic form (as listed below) is regularly used in general construction, in windows or shower screens for example. However, fancier versions are also used but mainly to highlight parts of buildings as architectural enhancements, or internally for decorative purposes. We will be looking in short at the basic forms of glass regularly used by builders here.

Basic types of glass used in construction:

• Flat or Float glass / Pilkington glass

• Chromatic glass / Smart glass

• Self-cleaning glass

• Laminated glass / Shatterproof glass

• Toughened glass / Tempered glass

Float Glass / Pilkington Glass

Modern-day windows are made from float glass, also known as soda-lime glass. It is a sheet of glass prepared by floating molten the glass on a bed of molten metal, normally tin or lead. This method gives the glass a uniform thickness and a very flat surface. The process of making a float glass is also known as the Pilkington process (named after the British glass manufacturer, Sir Alastair Pilkington, who invented the technique in the 1950s in Merseyside UK). Float glass comes in various thicknesses, sizes, and weights to meet all building requirements.

Chromatic Glass / Smart Glass

Chromatic or Smart glass is used in place of regular glass to control the level of daylight passing into the interior of a room. Light transmission properties are altered when voltage, light or heat is applied to the glass. Normally, the glass changes from translucent to transparent, changing from blocking some wavelengths of light to letting light pass through. There are three forms of chromatic glass, photochromic – which has a light-sensitive coating on the glass, thermochromic - which has a heat-sensitive coating on the glass, and electrochromic -light-sensitive glass transparency of which can be controlled by an electrical switch. This type of glass is often used in meeting rooms.

Self-Cleaning Glass

The self-cleaning glass keeps itself free of dirt and grime. Here the special coatings applied to the glass fall into 2 categories, hydrophobia and hydrophilic. Both are self-cleaning but their method is different, the former by rolling droplets and the latter by sheeting water that carries away dirt. In addition, the hydrophilic coatings based on titanium dioxide have an additional property; they can chemically break down absorbed dirt in sunlight. It is, therefore, very easy to maintain.

Laminated Glass / Shatterproof Glass

Laminated or shatterproof glass is a form of high strength security glass. If broken, the two or more layers of glass are held together by one or more plastic like interlayers. This interlayer’s keep the glass bonded and prevents it from breaking into large sharp-edged pieces, instead of creating a spider’s web appearance when the impact is not enough to completely pierce the glass. The panes are heavier than normal glass panes. Laminated glass is normally used where the glass could fall and hurt someone if shattered, e.g. Skylight glazing and car windshields, and also for aquariums and architectural applications. There are two main types of the interlayer, special "acoustic PVB" and EVA. Both forms increase the sound insulation rating of a window. An additional property of laminated glass for windows is that a PVB and EVA interlayer can block essentially most ultraviolet radiation, with EVA blocking up to 99.9% of the UV rays.

Toughened Glass / Tempered Glass

Toughened or Tempered glass is a type of heat-strengthened safety glass. It is physically and thermally three to seven times stronger than regular annealed glass. Tempering is the process of putting the outer surfaces of glass in compression and the interior into tension. Such stresses cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards as regular glass does. The rough chunks are less likely to cause harm. As a result of its safety and strength, tempered glass is used in a variety of demanding applications, frameless shower screens or doors, table tops, shelves, fireplaces, balconies, skylights, large windows, windows which extend close to floor level, sliding doors, and near swimming pools.