What is safety glass ans why is it more expensive?

There has been an increase in the demand for “safety glass” and other glazing products to keep commercial buildings safe.

One of the major safety concerns for commercial building owners has been forced entry. While large doors and windows are essential and aesthetically valuable for such buildings, burglars often target these parts, which are the Achilles heel of buildings.

As such, glass companies continue to come up with better glass products to meet the needs of safer glazing products required by commercial building owners.

Laminated glass and tempered glass are the two common glazing products used in the prevention of forced entry. Commercial building owners need to understand the differences between the two glass types before choosing the best one for their needs.

Before we get into the differences between these two types of security glass products, we’ll first take a look at some characteristics that define each of them and will then compare these characteristics to give you a rough idea of when it’s better to use laminated and when tempered glass. 

Laminated Glass

Breakage pattern on laminated glass

1. What is Laminated Glass?

Laminated glass is created from two pieces of tempered or regular glass, between which is a layer of clear plastic film. The glass is first treated to eliminate the existence of any air bubbles/pockets and is then heated for the first round of melting. 

After this initial process, the glass is heated again but this time under pressure to finalize the glass product. Stronger laminated glass can be made by adding more layers. 

Laminated glass can be very slightly stretched (not in a rubber band way) so that it can be placed in its position properly. 

2. What is the Purpose of Laminated Glass?

Laminated glass was originally designed for use in vehicle windshields to reduce the frequency of injuries in victims of car accidents. When one side of the glass experiences an impact, only that side will shatter, not the entire glass. The pieces also stay together after one or two impacts (depending on their severity) so the risk of injury is minimal. 

Laminated glass also provides soundproofing of high-frequency sounds, and on top of that, it also blocks 97% of ultraviolet radiation. 

Fun Fact: Minor impact damage in laminated glass can be repaired by using a special clear adhesive resin. 

3. Where is Laminated Glass Used?

Laminated glass can be found in all kinds of forms and ‘locations’, including as windows of tall buildings, balconies, skylights, frameless glass railings, and vehicle windshields. Certain commercial business owners may also request laminated glass if the sound levels are too high outside of the building. 

Tempered Glass

Breakage pattern on tempered glass

1. What is Tempered Glass?

Tempered glass is a piece of traditional (ordinary/annealed) glass that is heated and cooled to give it its safety properties. This heating/cooling process is called ‘tempering’ which is where the name ‘tempered’ glass comes from. 

Tempering involves heating and cooling the glass rapidly which causes the glass to develop its safety properties in an interesting way. In essence, quickly cooling hot glass causes the outside surface of the glass to harden faster than it does in the center. The result of this process leaves the center of the glass ‘in tension’ which makes it much stronger and more durable than non-tempered glass. 

The main difference between tempered and laminated glass is that tempered glass is a single piece of glass while laminated glass consists of two (or more) glass sheets surrounding a layer of plastic film. 

2. What is the Purpose of Tempered Glass?

Tempered glass is stronger than ordinary glass but it can still shatter. Shattering tempered glass requires a huge amount of force. If someone were to break it, it would shatter into a web-like interlocking pattern, usually remaining in its frame. However, there is the possibility that the broken pieces will fall out of the frame if the connecting pieces are also weak. 

Nonetheless, tempered glass is designed to break into small, less dangerous pieces instead of jagged and sharp edges. 

Tempered glass also can’t be repaired. 

3. Where is Tempered Glass Used?

Since tempered glass belongs to the ‘safety glass’ group of glass, it’s primarily used when it may pose a risk to family and friends. While it shouldn’t be used in high-risk areas where even more brute-force prevention is required, it is useful to have in many types of situations.

Fun Fact: Tempered glass is also found in vehicles. Laminated glass is used in the windshield whereas tempered glass can be found in the car’s passenger seat windows and rear windows. 

You can also find tempered glass in fridge shelves, skylights, shower doors, bathroom doors, oven doors, and storm doors. 

Laminated Glass vs. Tempered Glass

Laminated and tempered glass differ by a number of features. Such features influence the choice of glass type for commercial building owners to install on their doors and window systems. Here are the main points of difference between laminated glass and tempered glass.

1. Manufacturing Process

When discussing laminated glass vs. tempered glass, the manufacturing process is the primary difference between the two. Laminated glass is made by bonding one or two layers of glass with a layer of resin, commonly polyvinyl butyral (PVB) – the clear plastic film we mentioned earlier.

PVB is the interlayer that holds the glass layers together, even when the glass breaks or is impacted with great force. The process of producing laminated glass involves bonding these glass layers and the interlayer under heat and pressure.

This produces compact glass that holds in place rather than shatters when hit by attackers and burglars.

On the other hand, tempered glass is produced in the process of toughening standard glass to give stronger glass. This toughening process makes it several times stronger than laminated glass. This process often involves heating, high-pressure, and chemical treatment procedures.

These treatments give the glass a better balance of internal stress, which makes it better at resisting force up to certain levels.

Despite its strength, tempered glass breaks and shatters when impacted by huge forces from bullets or other weapons.

2. Strength

Another way to look at tempered vs. laminated glass is by comparing their strength.

The strength of these two safety glass types comes from their production process. While both of them fall into the category of “safety glass”, their strength differs and each has a unique way of preventing forced entry and protecting building occupants.

Laminated glass is strong because it can withstand the force of a rock or bullet without shattering and falling off the window or door frame. Its strength can be attributed to the glass layers and the resin used as the interlayer. What’s more, the pressure and heating process adds to its strength and makes the glass up to 5 times stronger and 100 times stiffer than standard glass.

On the other hand, tempered glass is known for its strength and resistance to force. Throughout the manufacturing process, the glass goes through stages of heat, pressure, and even chemical treatment to make it tougher than regular glass. Because of this, tempered glass is considered stronger than laminated glass since it can withstand stronger impacts and force than laminated glass. 

3. Applications

When looking at the laminated glass vs. tempered glass comparison, the application of the glass types may also be considered.

Due to their different characteristics, you’ll often find laminated glass to be used in situations where tempered glass isn’t a good option and vice versa. However, it isn’t uncommon to have both types of safety glass in specific situations. 

Commercial building owners who seek security for their valuables should consider laminated glass.

Laminated glass windows and doors are especially essential for commercial buildings, where there is a need to prevent forced entry and safeguard valuables. The interlayer in laminated glass creates a significant barrier, which makes it difficult for burglars and attackers to breach.

Tempered glass also suits skyscrapers and commercial buildings with large windows. This way, the views outside are not distorted, and building occupants are protected from the weather (especially storms).

4. Custom Display

Besides security purposes, glass is also used for many other applications.

Lately, laminated glass has become a favored material in indoor and outdoor graphic projects. Photography and digital images have become common choices for incorporating design elements into architectural glass, and laminated glass has become the best glass to incorporate such design elements.

Given the presence of the interlayer in laminated glass, designers can now use online design tools to include visual imagery on the glass. As such, laminated glass continues to be used by brands who wish to create a great impression on the public.

Other than architectural and safety purposes, tempered glass has seen limited applications compared to laminated glass. Since tempered glass is purely made of glass, the incorporation of digital elements is not possible, as is the case with laminated glass.

While this discussion may not come up often, the tempered glass vs. laminated glass comparison may often highlight such tech-based applications of laminated glass.

5. Price

While making the laminated vs. tempered glass contrast, the cost of these safety glass types also comes into play.

Due to the complexity of the manufacturing process and the materials involved, laminated glass is more expensive than tempered glass. The manufacturing process involves the use of resin and glass panes. The heating and pressure treatment processes also add to it being more costly than tempered and standard glass.

Tempered glass is also costly to purchase and definitely more expensive than standard glass, but less costly than laminated glass.

Depending on the preferences of a commercial building owner, the cost is another point of difference that dictates the choice between laminated and tempered glass.

Conclusion

The laminated glass vs. tempered glass comparison often comes up when building owners are considering the best option for their window and door systems. Some of the main features to look at to differentiate the two include the make-up, strength, cost, and the intended purpose for the glass installation.

Looking for residential protection? At Riot Glass, we specialize in protecting your property with our patented bullet-resistant system, designed specifically for aluminium framed windows. Not sure if Riot Glass is right for your home? Explore our FAQs.