Glass and glazing
There are many test standards available to determine glass specification requirements for life-safety applications. Glass can be specified for bullet resistance, and window film added to glass may enhance its ballistic properties.
Keep in mind, most glass safety films were initially made for solar control and converted to vandal resistance. Only one applied film is recognized as tested to resist active shooter attack incidents when applied to 6.53 mm (0.250 in.) tempered glass. This 23-mil-thick film’s properties feature a break strength of 0.0044 kPa (0.00063816604723 psi).6
There are many laminated, insulating glazing units tested to mitigate blast hazards and ballistic attacks. These units may be enhanced with low-e, solar reflective, or tinted coatings to achieve a project’s energy efficiency and aesthetic design intentions. Some also may be specified for fire ratings, hurricane impact resistance, noise reduction, and other performance requirements. While the glass is significant, it is only one component of a whole fenestration product assembly.
Aluminum framing
The glazing units of a complete fenestration assembly are secured on all sides by the framing members. In schools, universities, and other educational, institutional and commercial buildings, extruded aluminum is the framing material of choice.
Aluminum is versatile in its fabrication and installation. It can be shaped into rectilinear or curvilinear forms in almost any size. It can be finished in durable anodized tones which highlights its metallic properties, painted in nearly any color, or coated to resemble natural wood, terracotta, or stone.
Since aluminum is a conductive material, the extruded metal’s interior and exterior surfaces must be separated to minimize thermal bridging. Thermally “breaking” and insulating the frame allows whole fenestration assemblies
to meet condensation resistance goals, model energy codes, and other project-specific requirements. For high-security performance objectives, aluminum framing may be reinforced with steel for additional rigidity and strength.7
Aluminum has a long lifespan and is low maintenance, making it an economical option for many school districts and college campuses. It is also considered a sustainable material choice. Framing components also can be manufactured with recycled aluminum content. At the end of its useful life, the metal once again can be recycled.
Shooter Attack Test Method
Educational project specifications may now reference the Shooter Attack Test Method for windows, doors, and other fenestration assemblies. Developed by subject matter experts and recommended by the NSSPA, this rigorous, engineered process tests a whole product assembly’s ability to delay an attacker with a gun.
Shooter Attack Test Method8 criteria are based on real-life data and analytics of shooter attack incidents. Improving upon existing industry standards, it is the only test to add ballistic testing immediately prior to impact testing. First, the glass is shot 10 times with an AR15 using .223 rounds. The glass is then struck twice with a 45.4 kg (100 lbs) ram at 67.8 Nm (50 ft/lb).
