Jim Richards | |
The appropriate thickness of security window film depends on what you need to protect and what you need to protect it from.
There are many types of plastic films you can apply to existing windows to alter how they look or perform. If you want to strengthen a window, slowing or foiling attempts to break the glass and gain access to the building, you need a security window film formulated specifically for that task.
Common Security Window Film Thicknesses
These most commonly come in 4, 7, 8, and 15 mil thicknesses. This unit of measurement can be a source of confusion; a “mil” is not the same as a “millimeter.”A “mil” is a unit of thickness used in manufacturing. One mil is one thousandth of an inch, i.e., .001 inch. Therefore, a 15 mil sheet of security window film is about half the thickness of a credit card. A 15 millimeter sheet of security film would be about as thick as your pinky finger.
The right security window film thickness depends on your application and the type of threats you want to protect from. One of the most useful ways to identify the right security window film and product features are to ask two questions:
- To what standards is the film tested?
- How is the film anchored?
Anyone can call any window film “security film,” regardless of the type of protection it provides. That’s why third party testing to industry-accepted standards is so important. Testing standards give consumers a clear understanding of the type of performance they can expect from their security window film products.
Most reputable security window films are tested to one of more of the following four testing standards:
- ANSI Z97.1 Standard for Safety Glazing Materials Used in Buildings: This is an impact testing standard. It uses a weighted pendulum to strike the sample. The film-treated glass can crack or break after being struck, as long as it doesn’t create an opening large enough for someone to force their hand through.
- ASTM E1886/E1996 Large Missile Impact: This is a set of standards that help engineers evaluate how well exterior windows, doors or shutters will cope with hurricane-like conditions. “Large missile” means a 2x4” launched at 50 feet per second, simulating hurricane-driven debris, and approximating the effect of a brick or cinder block thrown at an exterior window.
- GSA Blast: This is the U.S. General Services Administration’s standard for testing how well complete window systems with explosions. Ratings range from 1 (“Glazing does not break. No visible damage to glazing or frame”) to 5 (“Window system fails catastrophically”). In between are 3a and 3b: window fragments enter the protected space, but not far or fast enough to cause injuries.
- UL-972 Anti-Intrusion: This is a standard for materials intended to resist “burglarious attacks of the hit and run type.” During the test, a 5-pound steel ball is repeatedly dropped near the center of a horizontally-mounted sample. The drop height is at least 10 feet. If the ball breaks through, the sample fails the test.
What About Bulletproof Window Films?
“Ballistic film” or “bulletproof window film” do not exist. No product on the market today can be applied to existing windows and reliably stop even small caliber bullets.
We conducted exhaustive studies and found that even multiple layers of the thickest available security window films failed to reliably protect from bullets. The issue isn’t the film, but the existing windows.
A bullet-resistant glass assembly has very specific glass with specific properties that hold true over time. If you go to a random building, you’ll probably be able to determine that the window is ¼” glass or a 1” insulated glass unit; you may be able to identify whether the glass is tempered or annealed. But you don’t know its mechanical properties, the manufacturer, when it was made, or the standards to which it was made. Security window films depend on that glass to be part of your structural barrier. It’s a key part of the system’s structural integrity. So if the glass doesn’t provide adequate structural features, you can’t count on it for protection. And in most cases, you simply can’t guarantee glass in any given building has the right properties to guarantee bulletproof protection.
This is also why you don’t see window films that have been tested against UL ballistic standards: they would have to be tested alone (not applied to glass) and there is currently no transparent plastic film that can stop a bullet.
TSS Security Window Films Offer Reliable Forced Entry Protection
TSS offers a range of security window films in 7 mil, 8 mil, and 15 mil thicknesses. These offer the best combination of price and performance.
Our experts typically recommend using security window film of all thicknesses as part of a ballistic barrier system. We often direct customers to use film in places in a building exterior where glass needs to be reinforced, but where it’s not necessary to stop bullets and protect life and human safety.
Ready to make your building a safer place? Please don’t wait to reach out to us. Your security is our priority. We can work with you, your security consultants, and your timeline to craft a solution that meets your needs and protects what matters most.
Contact our ballistic security experts to learn more or get started today.
