What’s the Strongest Glass Available for Commercial Building Applications?

Contents
- **Tempered vs. Laminated Glass: Which Is Stronger?**
- **Ballistic Glass and Polycarbonate Security Glazing**
- **Is Thicker Glass Always Stronger?**
- **Enhancing Glass Performance with Security Window Film**
- **Conclusion**
While strength isn’t the first thing many people think of when it comes to Glass, modern technology has made some safety glass types extremely tough. Today, products such as ballistic-resistant glass offer outstanding protection for commercial buildings by not giving way to bullets or heavy impacts. Laminated safety glass is generally recommended for everyday high-strength situations. With multiple layers, it offers better impact protection than usual glass.
Of course, no glass is unbreakable, but following these protocols makes breakage much less likely, and safer if an incident does occur. This article examines various types of safety glass, such as tempered, laminated, polycarbonate security and ballistic varieties, detailing what they add to security, when they are best used and how window films increase their protection.
Tempered vs. Laminated Glass: Which Is Stronger?
Two main types of safety glazing are tempered and laminated glass, which have different advantages.
Heating makes tempered glass approximately four times stronger than annealed glass of the comparable size. This strong tensile strength helps a tempered pane withstand harsh winds and impact without easily breaking.
If the glass does break, it falls apart into small pieces instead of sharp-edged shards, increasing safety. However, as tempered glass is built to break into small pieces under extreme pressure, it loses all strength once cracked.
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Laminated glass, on the other hand, is built to stay intact even when cracked. It sandwiches a tough plastic interlayer between two or more glass sheets. A laminated pane may crack in a spider-web pattern upon heavy impact, but the pieces adhere to the interlayer instead of falling out. The glass “breaks safe,” like a car windshield, maintaining a barrier much harder to penetrate than a single pane.
This gives laminated glass a security advantage – even if it’s not quite as hard to crack initially as tempered glass, it will continue to withstand after cracking. In terms of impact resistance, laminated glass can absorb huge forces (hurricane debris, a swung crowbar, etc.) while remaining in the frame.
Ballistic Glass and Polycarbonate Security Glazing
The toughest option for glass, bullet-resistant glass, is often used for buildings such as embassies, government spaces, jewelry shops, and bank teller stations that need extra safety. It’s made by laminating glass with polycarbonate to stop and absorb bullets.
Ballistic glass usually consists of multiple layers: hard layers of glass to blunt and slow the bullet, and softer polycarbonate layers to catch fragments and add elasticity to resist shattering. The result is a thick composite that looks like standard glass but can stop firearms from handguns up to high-powered rifles (depending on its UL 752 rating).
Ballistic glass for commercial use is commonly seen in sensitive facilities – government buildings have it (the White House and Pentagon famously use bullet-resistant windows), and many banks, cash handling centers, and luxury boutiques install ballistic-grade glass for protection.
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One form, often called glass-clad polycarbonate, sandwiches polycarbonate between glass layers and is considered one of the strongest glazing products available. It provides extreme impact resistance, guarding against bullets and sustaining prolonged physical attacks with heavy tools.
Another category is polycarbonate security glazing. Polycarbonate is a transparent plastic, not glass, but it is virtually unbreakable by blunt force—a polycarbonate window can take repeated blows from a hammer without shattering. This makes it ideal for riot-prone locations or extreme vandalism risks. Some retail stores have installed clear polycarbonate panels over (or in place of) glass to prevent looting damage.
Is Thicker Glass Always Stronger?
A common misconception about choosing strong glass is that increasing its thickness will make it stronger. In fact, the durability of glass depends mainly on its type and the way it shatters, rather than simply its thickness.
While a thick standard annealed glass can endure gentle pressures, it is still very likely to break into shards if hit hard. Meanwhile, a much thinner tempered glass could withstand that same impact without breaking, thanks to the tempering process (not thickness) that gives it strength.
Similarly, a laminated glass unit derives strength from the layered construction and interlayer, not the total thickness. Two layers of 1/4″ glass with a laminate in between will usually outperform a single 1/2″ monolithic glass in security terms.
Ultimately, the quality of glass lies in its makeup and build (tempered, laminated, and polycarbonate), not in its thickness alone. Like laminated or ballistic glass, multilayered glass offers more strength than a single very thick sheet of regular glass.
Enhancing Glass Performance with Security Window Film
Not every project can afford to install all new laminated or ballistic glass. If you have existing ordinary windows but want to improve their strength and safety, one cost-effective solution is to apply security window film. These are heavy-duty transparent films (made of multi-layer polyester) that adhere to the interior surface of glass.
While a film can’t turn regular glass into “unbreakable” glass, it can significantly boost impact resistance and shatter protection. In a break-in attempt, a window treated with security film will hold together much like laminated glass–if the glass cracks, the film keeps the pieces in place, forcing an intruder to spend much more time and effort to get through.
In essence, security window film is an additional layer of defense. Note, however, it’s not a substitute for laminated or ballistic glass when facing determined attackers or bullets.
Conclusion
There is no one-size-fits-all “unbreakable glass,” but you can dramatically increase a building’s safety and security by selecting the right commercial impact-resistant glass solution. Evaluate your threat scenario–forced entry, severe weather, or even a ballistic threat–and choose accordingly.
For further reading on glass strength and safety, check out our related post Unbreakable Glass: Myth vs. Reality, which explores why no glass can be truly unbreakable and how safety glass works. If you’re looking into upgrading your property’s glazing, explore our range of security window film solutions to enhance your existing glass.