BULLETBLOCK - bullet proof glass, windows, and doorsBallistic protection is especially important today. There are many different types of protection for building owners to consider. But bullet resistant windows and doors, including glazing, should certainly be included on your list.

Insulgard offers a line of these products, known as BULLETBLOCK. To learn more about the options and the important safety benefits that these products provide, here’s a guide.


BULLETBLOCK is a selection of bullet resistant products that are made to provide an extra layer of protection from firearm ballistics. These products run the gamut from standard windows, doors, and framing systems to specific entryway designs and even interactive transaction windows and accessories. Essentially, all of the BULLETBLOCK products designed and tested to withstand ballistic attack protecting employees, students, and members of the public in the event of a shooting incident.


BULLETBLOCK doors and framing components are constructed with extruded aluminum in 6061-T6 alloy/temper or equal while glazing products can be made of acrylic, polycarbonate and glass or a combination of all. Lower levels of BULLETBLCOK glazing products can be monolithic sheets of acrylic but more typically BULLETBLOCK glazing consist of multiple layers of glass and polycarbonate laminated together in order to provide extra protection from ballistics.

The combination of glass and polycarbonate results in a product that is much lighter weight than an all-glass makeup but still provides protection from ballistic elements when necessary. Also, although when shot the glass will break on these laminated products, the laminate will for the most part stay intact and not shatter into shards of glass, which prevents protected areas from becoming completely exposed and ensures that you won’t have to deal with extra dangerous debris in the middle of an emergency situation.

Different combinations of these materials offer different types of protection. Underwriters Laboratory testing standards offers a system for evaluating the ballistic protection of each option. For example, in order to meet UL Level 1 standards, a product must withstand three shots from a 124-grain 9mm full copper jacket with lead core at an fps between 1175 and 1293. And in order to meet UL Level 8, a product must provide protection against five shots from a 150-grain 7.62mm rifle lead core full metal copper jacket military ball at an fps between 2750 and 3025. You can read more specifics about those testing standards and requirements here.

How Does Bullet Resistant Glass Work?

Bullet resistant glass essentially creates a very thick pane of clear material that combines layers that are somewhat pliable and layers that are very rigid. This combination of materials and the products used to bond them together absorbs the impact of the bullet and stops the projectile while not allowing any spall or shattered glass to enter the safe area providing absolute protection to the occupant..

In order to be effective, typically the higher the level of protection required the more layers and interlayers required to meet that protection and the thicker the overall makeup needs to be. For lower levels of ballistic protection such as UL752 levels 1, 2 or 3 a glazing makeup close to 1” will do the job but if a higher level of protection is required, such as UL752 Level 8, the glass makeup required to provide this level of protection will exceed 2”. This is because the size and velocity of the round increases greatly and more layers and interlayers are required to stop the bullet and disperse the load of the impact. It is important to note that UL752 testing requires complete protection meaning not only can the bullet not penetrate the glass but there can be no glass spall come to the interior. If someone claims their product is UL752 low spal there is no such listing from UL and it does not meet the UL752 testing requirements .

Applications for Bullet “Proof” Windows and Doors

First of all, it’s important to note that there is no such thing as truly “bullet proof”. There is no material that can hold up against powerful ballistics forever. That’s why “bullet resistant” is a more accurate term and the level of protection is clearly defined.

Essentially, bullet resistant windows, doors, and glazing can be used in any location where ballistic protection is wanted or needed. This often includes schools, churches, mosques, government buildings, banks, and convenience stores. Unfortunately, the U.S. saw a big rise in k-12 shooting incidents in 2018, so putting protections in place is top of mind for those in the education field and the public sector as a whole.

When it comes to actually implementing these bullet resistant glazing products, you can really customize the products to suit your specific needs with BULLETBLOCK. For banks and buildings where employees need protection while dealing with members of the public, transaction windows, counter line systems and accessories can be a major benefit. For government buildings and facilities where you might have security screening areas, bullet resistant entryways may be more beneficial to protect those who have made it through those checkpoints. There are also bulletproof security windows and doors that provide protection for a building’s exterior.

Product Specifications

There are a huge array of BULLETBLOCK products that you can choose from based on your specific needs and preferences. We’ll go over some of the key characteristics of a few of these popular products below.

44/350 Door System is a full or half vision aluminum door tested to meet UL752 Levels 1-3 and is available as a single of pair of doors.
TH600 Window System is a 2 ½” x 6” deep aluminum framing system that can be used for punched windows or a storefront application that has been tested to meet UL752 levels 1, 2, 3, 4, 5 or 8.
MP1.25 Acrylic is a UL752 level 1 glazing that is 1 ¼” thick, weighs 7.7 lbs/sqft, is easy to fabricate and polish and provides water-like clarity.
Lexgard SP1250 Laminate is a four ply polycarbonate that is 1 ¼” thick, weighs 7.7 lbs/sqft, is easy to fabricate and offers forced entry and UL752 Level 3 protection
BALULN32 Glass-Clad Polycarbonate is 1.28” thick, weighs 14.4 lbs/sqft, meets UL752 level 5 and the exterior glass surface provides excellent weathering for exterior applications.

You’ll need to carefully evaluate your needs to determine which bullet resistant systems will be the most beneficial for your building security. For instance: Do you need exterior protection, entryway protection, or transaction window protection? What type of ballistics threat are you most likely to encounter? Who are you trying to protect? Is the protection required at all times or just during certain times of the day or night?

You can check out a full selection of Bullet Block products on Insulgard’s website, along with product specifications and data sheets on each offering. Or contact Insulgard today. One of our experienced team members will be happy to discuss your needs and help you determine the type of Bullet Block products that are most likely to suit your specific needs.

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