All You Need To Know About Architectural Glass
Glass is one of the most important materials used in the building construction and technology. It is mostly seen on Facades, doors, windows, railings, etc. It is well known for its visual see though and light transmission. Glass connects indoor to outdoor and outdoor to indoor.
Glass in Architecture is used for
- Facades – Fenestrations (doors, windows),cladding in facades
- Building construction – Glass Partitions walls, floors, skylights, roof panels, display shelfs in showrooms
- Glass in insulation – glass wool
It is made up of number of materials such as sand, soda ash and limestone. Calcium sulphate and dolomite are added in smaller amounts including addition of broken glass or cullet.. It is formed by high-temperature fusing of silicates, alkalis, lime and other materials. Minerals are added to obtain colors.
Glass can be manufactured in sheet form from 1/2″ to 2″ (2 to 50mm) thick used for various purposes. These panes are produced in three basic ways:
Sheet glass is produced by drawing out molten glass and subjecting both sides to heat. Resulting faces are not truly parallel since it in not further treated. This technique has been replaced by better methods.
Plate glass is ground and polished after being drawn from the molten state, producing more parallel surfaces.
Float glass (commonly known as window glass) has replaced sheet and float glass. It is made by floating molten glass over a molten metal such as tin, producing an even layer of glass that ends up polish on both sides.
Glass is also melted and forced through small orifices to produce thin glass fibers. These are used in manufacturing building insulations and various fibers for textiles.
Thickness of Float glass varies from 3mm-25mm.
Non-sheet Products and Sheets Products
Non-Sheet Products Include
- Glass Fibres
- Glass wool
- Cast glass
- Glass Blocks
- Glass Pavers
- Cellular of Foamed glass
Sheet Products Include:
- Traditional blown and drawn glasses
- Suitable for conservation work where old glass requires replacement.
- Float glass
- Curved sheet glass – glass sheets bent into curvatures.
- Self-cleaning glass – The invisible hard surface coating has two special features.
- Surface incorporating titanium dioxide is photocatalytic, absorbing ultra-violet light, which with oxygen from the air, breaks down or loosens any organic dirt on the surface.
- the surface is hydrophilic, causing rainwater to spread evenly over the surface, rather than running down in droplets, thus uniformly washing the surface.
- Clear white glass
- Patterned glass – glass with strong patterns and designs
- Screen printed glass – ceramic frit is screen printed onto clear or tinted float glass.
- Acid etched glass and sandblasted glass – small range of patterns.
- Various types of Architectural and decorative glass mentioned below.
Architectural glass is also made in different thicknesses, strengths, colors, tints, and finishes. It can be frosted, ribbed, pebbled or curved to suit a variety of purposes.
Safety glass (commonly called annealed) :
- Resistance to breakage from impact and thermal stresses.
- Tempered, wire, laminated, or security glasses are available to help prevent injury.
- Tempered (or toughened) glass is used as the most common form of safety glass.
- Toughened glass cannot be cut or worked, therefore all the cutting, drilling, polishing has to done in advance.
- It withstands considerable extremes of temperature.
- Safety glass can also include fire-resistance glass, which is used in fire-rated partitions that can be made with wired-glass/laminated/toughened glass.
- Toughened calcium-silica-based glasses can achieve 90 minutes’ fire resistance with respect to integrity.
- Made as double or triple glass to reduce heat loss and gain in buildings.
- It consists of two or three layers of glass that are separated and sealed, with an air space (or gas) between layers. These spaces vary from 6mm to 12mm.
- Insulated glass can be produced as uncoated glass or coated, whereby one layer can have a thin layer of metal oxide applied that decreases the transmission of heat through the glass.
Common glazing materials
- Common glass, often called clear window glass.
- General usage in doors, windows, mirrors, glass shelves, etc.
- It is produced by bonding layers of glass together with inner plastic layer of polyvinyl butyral (PVB);or a low viscosity resin; varying inner plastic layer can control heat, glare and sound transmission.
- Increases the impact resistance.
- Heat strengthened glass is typically used in Laminated glass.
- Upper storeys, corners’ of high buildings (where resistance to wind pressure is necessary), spandrels
- Used as safety glass, roof panels, overhead glazing in buildings and in motor vehicles.
- Heat strengthened during manufacturing, difficult to break.
- Used as Entry and shower doors, windows subject to impact.
- Holds together when subjected to high temperatures, impact and air pressures.
- Used as common safety and fire-resistive assembly in buildings, overhead glazing.
Reflective and heat-absorbing glass
- Reflective glass and films reflect or absorb solar radiation.
- It has a thin film of transparent metal or metal oxides bonded to the glass surface to reflect the sun’s rays.
- It is produced by adding coloring agents (usually gray, green, or bronze tints) during manufacturing.
- Metals are integrally cast into the glass and are charged electrically to become opaque or clear, depending on the need. These types are often called electrochromic glazing.
Decorative glass is an expressive material that can be used in both utilitarian and decorative or aesthetic treatments.
Hand-Blown and Molded Glass
- It is the oldest and most popular art glass forms. It is made by dipping a hollow metal rod into molten glass material and blowing a bubble. Before the glass cools, the glassblower uses tools to roll, twist, or shape it, creating a distinct, handcrafted look.
- Molded glass is a mass-production of the hand-blown process. Glass is blown or pressed into moulds during the molten stage. Many glass items are made this way as seen in dishware and bottles.
Engraved and Etched Glass
- Engraved Glass is made with wheels and various abrasives, to cut the surface, producing fine decorative and pictorial effects.
- To produce etched glass, either sandblasting or acid techniques are used to create art on the glass surface after the glass is blown or cast.
- The technique of etching produces a shallower design than engraving, and it is often used to imitate the more deeply incised engraved technique.
Beveled, Leaded, and Stained Glass
- Beveled Glass is made by grinding and polishing the edges of a piece of thick glass at an angle. Beveling is used for leaded glass windows, mirrors and doors and in insets in wooden frames for decorative purposes.
- Leaded glass generally refers to transparent or colored glass, such as in a window.
- Stained glass refers to glass that has been colored by glazing, pigmenting or painting. It is set in lead or strips of copper foil for decorative uses and items such as lampshades and windows.
The degree of privacy afforded by glasses depends on
- Pattern of glass
- Relative lighting levels on either side
- Proximity of any object to glass
Other Specialist Glasses
- Observation glass – used where unobserved surveillance is required.
- Mirror glass
- Anti-reflection glass – reduces surface reflection, thus increasing surface transmittance.
- Alarm glass – series of wires are installed into intruder alarm system to get activated when the glass is broken.
- Dichroic glass – creates optical interference effects.
- Sphere glass and cracked glass – used in feature walls as it consists of array of glass hemispheres.
- Anti-bacterial glass
- X-ray protection glass
- Sound generating glass
Smart glasses change their optical and thermal properties under the influence of light, heat or electric potential. These glasses offer highly responsive dynamic climate control to building facades.
- Photochromic glass
- Thermochromic glass
- Electrochromic glass
- Electro-optic laminates
- Intelligent glass