Within this growing segment of the industry, we find a new set of labels, terminology, and testing standards. At times these can get quite confusing and misleading. However, they do not need to be if you have a good understanding of a few key terms.
Proof vs. Resistant
Have you ever heard someone say that an object was Something Proof and in reality, it should have been Something Resistant? By definition, proof is “able to withstand something damaging; resistant.” That makes sense, until you consider the definition of resistant: “Opposed to something; wanting to prevent something from happening.” So, proof or resistant, tomato or tomahto? Do they mean the same thing?
Not exactly. While bulletproof sounds more impressive than bullet resistant, using the term bulletproof is an absolute statement and is not exactly true. At the end of the day, if someone or something wants in, the laws of physics will work against you. If something is big enough, powerful enough, hard enough, wet enough, fast enough-you get the picture-it’s coming in. For this reason, I would rather see the term “resistant” used in all descriptions having anything to do with bullet, blast, intrusion or storm rated entrance systems. Read on to find out why it’s important to direct attention to the testing standards by which products are evaluated when explaining the levels of protection or comparing products.
Let’s begin with looking at hurricane ratings. Most hurricane-resistant doors are required to meet at least one of following standards: ANSI (American National Standards Institute), ASTM (American Society for Testing and Materials), TAS (Testing Application Standard), IBC (International Building Code), or IRC (International Residential Code). Refer to the AHJ (Authority Having Jurisdiction) to determine which one is used in your area. Most test protocols will include static loads, cyclic loads, air infiltration, large missile impact, water infiltration and forced entry.
The most stringent of these requirements is approval in Miami-Dade County. If a product can make it through Miami-Dade’s NOA (Notice of Acceptance) protocol (TAS 201, 202 and 203), it can most generally be submitted in other states or regions (such as the Florida Building Commission and Texas Department of Insurance) with a high degree of confidence in approval.
A lot of homework is required for an engineering team to determine how a product will perform under test conditions before sending it to the testing lab. This upfront work reduces the likelihood of a failure during testing. Water infiltration is an excellent example. Water is not our friend in the test lab. One drop of water that infiltrates a test specimen results in a failure. One important consideration to remember is that the size of the product that you intend to install cannot exceed the size of the specimen tested (although it can be smaller). The hardware/seals must be consistent with the configuration used in the approval. You can deviate from the approval only with permission from the AHJ.
Bullet Resistant (Ballistic)
Depending on the level of bullet resistance, there are several ratings by which products can be tested. There are a variety of testing methods, all of which are completed in a controlled environment at a certified test lab. The range of weapons varies from handguns to rifles, and the ratings are quite different depending on the standard to which you are testing. For example, you may hear someone refer to “Level 3,” which has a different meaning depending on which testing standard is used. Level 3, UL 752, calls for a .44 magnum handgun. National Institute of Justice (NIJ) Level 3 calls for the use of a 7.62mm (.308 Winchester) rifle. So, as you can see, there is a difference. I have worked on several projects developing bullet-resistant doors using a fiberglass pultrusion process. Believe it or not, steel is not always the answer. When used properly, fiberglass has excellent ballistic properties without the concern of deterioration due to rust or corrosion.
In some cases, there is a blast requirement for exterior entrance systems. There are a couple of different approaches for a product to achieve a blast specification.
1. Arena Testing: This is obviously the most interesting. As you can imagine by the name, this testing occurs outside in a controlled area, by setting off explosives to achieve the desired load and duration. The entrance system is instrumented to record the forces felt during the explosion. The advantage of using the arena test is that you are not limited to a product of a particular size. The downside with this method is that it is more difficult to obtain a specific pressure and duration due to the variation in explosive behavior.
2. Shock Tube: The shock tube is an instrument used to replicate and direct blast waves at a sensor or a model to simulate actual explosions and their effects, usually on a smaller scale. The advantage of using the shock tube is that you can repeat the test more accurately than arena testing. The disadvantage is that the size of the specimen is restricted by the size of the shock tube.
If you are looking for solutions that would slow down a perpetrator from gaining access to your buildings, one of the options is an intrusion-resistant entrance. The definition of intrusion is; “the act or an instance of intruding; an unwelcome visit.” There are several test standards used depending on the approval. The most common are ASTM and UL, and the U.S. State Department forced entry test.
Depending on the data that you look at, the national average for the police to respond to a 911 call is between 6 and 10 minutes. The goal of an intrusion-resistant entrance system is to delay intruders from gaining access until the cavalry arrives. These systems may or may not be bullet resistant-but remember the object here is to delay the intruder from gaining access to the facility, not to stop a bullet.
There are two innovative variations of intrusion-resistant glazing that can be utilized for this requirement. One option is a patent pending product that slows down intruders up to twelve minutes before gaining access. This glass is a bit more expensive but provides all the benefits of a glass vision lite that an end user may prefer.
The second option is a clear polycarbonate that has a scratch resistant coating. I strongly suggest packing a lunch if you are trying to break through this material. You can literally go after it with a sledgehammer and not break it. This polycarbonate is an inexpensive solution for intrusion resistance.
It is important to note that the glazing material is only one aspect of an intrusion resistant system. The doors and vision lite kits used to hold this glazing material are just as important. They must all work as a system to counteract the threat. When selecting intrusion-resistant products, it is important that you select intrusion-resistant doors, frames, glazing, and vision lite kits. The vision lite kits are usually reinforced with more fasteners and material to allow the system to withstand a threat. I know what you’re thinking: More fasteners? No one is going to buy that. Well, just because there are more fasteners doesn’t mean you have to see them. There are companies that have developed clever ways of disguising their intrusion-resistant glazing kits so to the average person it does not look reinforced.
How do I know what level of protection is needed for an entrance?
To summarize all of this, the load results for HVHZ approved systems are calculated in pounds per square foot, but what you need to know is what approval is required from your AHJ. With ballistic systems, you need to understand the caliber of bullet that your entrance must withstand in an attack, that will dictate the level of protection required.
For blast protection, you will need to know the blast load the product needs to withstand, calculated pounds per square inch (psi), as well as the impulse calculated in pounds per square inch and milliseconds (psi-ms). For intrusion resistance, you need to know the amount of time that you want to hold a perpetrator at bay. To be successful when ordering these types of systems, you must take the time to understand the science behind the products that will protect you and your students. Understanding the requirements of your state or local jurisdictions insures that you have products that meet the requirements for the project.