Glass is an ancient building material, which facilitated penetration of light into buildings.
Architectural glass is glass that is used as a building material.
There are many different types of glass with different appearance and properties, which can be used in various applications:
- Annealed glass
- Wired glass
- Heat-strengthened glass
- Heat-soaked glass
- Toughened glass
- Laminated glass
Annealed glass is the base glass that is form from the float glass process.
Toughened or tempered glass
Tempered glass is also known as Toughened glass.
Tempered glass is typically used in areas that:
- need increased mechanical strength versus annealed and heat-strengthened glass,
- drilled (prior to tempering) or used in point support systems,
- are subjected to thermal stress from temperature gradients, and
- locations requiring safety glazing without glass fall-out concerns,
- laminated glass applications requiring added glass strength and glass shard retention post breakage.
Heat strengthened or heat treated glass is also known as semi-tempered or semi-toughened glass.
The strengthening process increases the mechanical and thermal strength of the annealed glass, making it twice as strong as annealed glass. The process is similar to the traditional process of glass tempering, but the cooling cycle is less rapid.
Due to the relatively lower rate of cooling during the heat strengthening process, heat strengthened glass develops less stress as compared to fully tempered glass.
Heat-strengthened glass is typically used in areas that
- benefit from low optical distortion,
- need to avoid the potential of spontaneous breakage,
- need increased mechanical strength versus annealed glass,
- are subjected to thermal stress from temperature gradients, and laminated glass applications requiring larger break patterns such as hurricane, balcony (undrilled) and blast and glass shard retention post-breakage.
Heat-strengthened glass is not a safety glass product as defined by the various code organizations.
Heat soaked glass
Typically used for:
- High rise glass facades.
- Overhead glazing.
- Balconies and balustrades.
- Any application where a superior toughened glass is required.
Chemically Strengthened Glass
Chemically Strengthened Glass is annealed glass which is strengthened by a chemical exchange of ions.
Any of the above types of glass can be laminated.
Safety and security are historically the best-known characteristics of laminated glass as the interlayer tends to retain the broken glass shards and act as a penetration barrier.