While glass doesn’t absorb and distribute loads like steel or concrete, it does play a large role in a structure’s natural lighting and, of course, attractiveness.
Common types of glass used in construction include float glass, shatterproof glass, laminated glass, chromatic glass, and extra clear glass. Other popular glasses include glass wool, glass blocks, and toughened and tinted glass. The best type of glass should depend on the nature of the construction.
In this read, we’ll discuss the main types of glasses used in construction and their various properties. Ready? Then let’s take a more detailed look at each.
1. Float Glass
Float glass is produced through a melt process, whereby silica sand, potash, line, soda, and recycled glass are melted in and floated on a bed of molten tin. The melting of the main ingredients in a furnace ensures the resulting sheet is flat and uniform.
The molten mass used in manufacturing float glass is allowed to solidify gradually as it flows on the molting tin. Afterward, the mass is annealed to remove the various stresses induced as the molten mass cools and solidifies. Annealing is also vital in allowing the glass to become more stable, thus achieving a higher refractive index and density.
Tinted float glasses come in different colors depending on the coloring agents introduced during the melting stage. Common colors such as bronze and grey tints are obtained from selenium, cobalt, and iron. Blue tints are mostly made from iron and cobalt.
Advantages of Float Glass
2. Shatterproof Glass
This type of glass is highly resistant to breakage due to the inclusion of plastic polyvinyl butyral during manufacture. The added element prevents the glass from forming sharp-edged pieces that lead to further breakage during impact.Shatterproof glass usually comes in different levels. While the lower levels can withstand a considerable amount of impact, the higher levels provide more protection and can withstand greater impacts. This makes high-level shatterproof glass largely preferred in skylights, floors, windows, railings, and glass staircases.
Advantages of Shatterproof Glass
3. Laminated Glass
Laminated glass is among the most effective types of glass used in building construction. In order to manufacture laminated glass, two plies of normal glass are usually bonded together (strongly) with interlayers to form strong, permanent bonds. The interlayers help to support the glass, providing greater thickness and durability.
Laminated glass comes in various thicknesses and can be created using varying glass combinations or coatings to achieve useful properties like increased insulation or low emission.
The reinforced hardness of laminated glass makes it ideal for glass floors, aquariums, animal enclosures, glass stairs, skylights, and glass roofs. Laminated glass is also perfect for usage in buildings located in insecure locations or structures based in areas prone to natural disasters like hurricanes.
Advantages of Laminated Glass
4. Extra Clear Glass
As suggested by the name, extra clear glass stands out due to its transparent and colorless properties. This type of glass is a unique float glass type with extremely low iron content—hence its alternative name ‘low iron glass’ or extra clear glass.
Extra clear glass allows up to 92% of sunlight to be transmitted, which provides a very clear view. In order to produce extra clear glass, silica sand with low or no iron content is carefully mixed with other materials before being melted in a furnace. The resulting molten glass is cooled similarly to float glass, which ensures it produces extra clear glass.
Due to its enhanced clarity, extra clear glass is extensively used in interior or exterior applications where a clear view is preferred. Some of the common applications of extra clear glass include windows, doors, wall cladding, glass partitions, stairs, and handrails. This glass type is also used in solar panels as it allows for the smooth absorption of UV rays.
The clarity of extra clear glass also makes it ideal for commercial applications like jewelry showrooms, art galleries, glass elevators, museums, and aquariums, among other applications. Extra clear glass is also commonly used in laminated glass, which usually has more thickness since float glass is known to produce an undesirable dark green tint.
Advantages of Extra Clear Glass
5. Tinted Glass
Tinted glass is a highly convenient form of glass that is characterized by its unique colors. To produce tinted glass, manufacturers introduce color-producing ingredients that help to add a bit of color without affecting other properties of the glass.
Iron oxide is known to produce green coloration. Sulfur and cobalt add blue pigments to clear glass, while chromium is responsible for dark green coloration. Uranium adds a yellowish color to glass, while titanium usually gives off a yellowish-brown coloration.
Advantages of Tinted Glass
6. Hardened/Tempered Glass
Also called hardened glass, tempered glass is a common type of glass used in construction for its strength. To ensure the final product is strong, manufacturers tend to process normal glass with chemical or thermal treatments, which introduce strength-enhancing properties, thus making the glass tough.
As a result of chemical and thermal treatments, tempered glass usually breaks into tiny granular pieces instead of shards with sharp edges, thus reducing the chances of injury. In terms of thermal and physical strength, not too many glass types compare to tempered glass.
The impressive thermal resistance, safety, and strength of tempered glass make it ideal for explosion-proof and high-pressure applications. This explains its wide usage in partitions for hotels, offices, homes, and commercial buildings. Hardened glass is also ideal for usage on windows, doors, facades, and interior decorative panels.The unique properties of tempered glass also make it a popular option in constructing glass tabletops, frameless shower doors, cabinets, glass shelves, and glass near fireplaces.
Advantages of Hardened/Tempered Glass
7. Glass Block
Also called glass bricks, glass blocks are made when two halves with a partial vacuum are fused. The appearance of glass bricks tends to vary depending on size, texture, and color. The most popular glass block designs are patterned, clear, and textured faces, making this glass type highly versatile for commercial and residential buildings.
Glass blocks have a wide range of usage in the construction industry. Glass bricks with textured finish can be used in front door decorations at home as they allow for enough light to pass through without compromising privacy.
The ability to absorb light makes glass blocks an ideal option for bathroom partitions, internal walls, and bedroom windows. Glass block is also commonly used as a façade. It lets in enough light and warms up the entire structure due to its impressive heat absorption properties.
Advantages of Glass Block
8. Glass Wool
Glass wool is a well-known insulating material made from melted glass as the primary raw material. In addition to melted glass, other significant constituents of glass wool include silica sand and fixing agents. This type of construction glass is usually available as superfine wool and loose wool.
One of glass wool’s stand-out features is its versatility in terms of applications. It can be used in timber frame structures, drywall systems, steel frame buildings, and cavity walls. Glass wool is also commonly used in pipe insulation, industrial roof insulation, and soundproofing.
Advantages of Glass Wool
9. Insulated Glass Unit
Insulated glazing unit, also known as insulated glass unit, is recommended in areas with high air conditioning costs. This glass type is made when a cavity separates two or more glass panes before the edges are carefully sealed. For increased insulation effectiveness, the cavity is usually filled with non-conducting gas like argon or dehydrated air.
Insulated glass units are commonly used in structures that require thermal and sound insulation. You will find this type of glass in glass roofs, double glazed windows, glass facades of skyscrapers, and highrise buildings and skylights.
Advantages of Insulated Glass Units
10. Wired Glass
Wired glass is mainly used as a safety glass due to its impressive fire-resistant properties. The glass is carefully reinforced with strong wire mesh during production to enhance its durability and resistance to large impacts. The role of the wire is to hold the pieces of glass in place in case of impact.
Wired glass is commonly used in windows and partitions of schools, public buildings, hotels, government offices, and institutions due to its fire-resistant properties. The use of wired glass gives occupiers more time to respond during emergencies, especially since the glass won’t shatter even amidst high temperatures.
The fire-resistant property of wired glass means it is commonly used in hallways, stairwells, and emergency exits. It is also used in skylights, roofs, and fire-resisting windows and doors. Point to note, though: wired glass does not provide a clear view and should not be used in places where clear viewing is preferred.
Although this type of glass can withstand enormous pressure before breakage, it can prove unsafe once it breaks as the sharp mesh wires become exposed. The wires are also susceptible to rust, making wired glass inappropriate for usage in humid or acidic environments.
Advantages of Wired Glass
Engineering Properties of Glass
Glass is a crucial part of building constructions as it plays a vital role in transmitting natural light, insulating the interior, and adding to the aesthetic value of structures. Below are some of the main engineering properties of glass.
Glass is mainly known for its transparency, which transmits light to allow for great visibility, unlike steel and concrete. Glass can be transparent from one side or both sides, depending on the materials used during the manufacturing.
The transparency of glass greatly hinges on the type of materials used as some allow for great light transmission while others are poor at absorbing and distributing light. Therefore, when working on projects that need natural lighting, going for more transparent glass is preferred.
Recyclability and Workability
Compared to most construction materials, glass has a high degree of workability. The workability of glass stems from its ability to be molded into different shapes or types when melted. This gives architects and civil engineers a variety of options to choose from, especially in window and door designs.
Besides workability, glass is also known for its recyclability. That is, glass can be used for several functions in construction and can even be reused to produce concrete for construction.
Although not the strongest construction material, glass can be reinforced during production to increase its overall strength. Normally, the strength of glass depends on the modulus of rupture value. Since glass is known for its brittleness and ease of breakage, admixtures and laminates can be added to increase overall strength and resistance to loads.
When dealing with glass, transmittance can be defined as the fraction of light (visible) that passes through glass. Some glasses have high transmittance and are ideal for usage in windows and doors, while others score low in regards to light absorption and distribution.
The U-value represents the total amount of heat that can be transferred through the glass. Glass designed to provide thermal insulation should have a low U value. Glasses with great insulation properties are preferred for usage in environments with extreme temperatures. This is because the glass will either prevent heat loss during cold winters or prevent the absorption of external heat during the summer.
Low Thermal Expansion Value
Glass is preferred for use in a wide range of climates due to its ability to withstand potentially harmful weather elements. Courtesy of its high dimensional stability, glass is less likely to change in volume due to temperature changes, unlike other construction materials.
In terms of response to weather changes, glass is among the best materials to use for both internal and external components. This is because glass is less likely to deteriorate over time due to exposure to rainfall and extreme sunlight.
As evident throughout the article, there are several types of glass used in construction. From float glass to laminated glass, extra clear glass, tinted glass, hardened and shatterproof glass, there is a wide variety of options to choose from.
However, the trick is to choose glass based on the type of structure you’re working on. Extra clear glass, for instance, works best in scenic environments where a clear view is preferred. Checking on each glass type’s primary properties is crucial to ensure the right option is chosen for use in construction.