Blast Mitigating Glass should be designed, sized, installed, and utilized in concert with a project engineer.  Design guidelines and appropriate usage varies depending on project location, needs and specifications.  Please consult your Oldcastle BuildingEnvelope® salesperson with questions regarding Blast Mitigating products.

The following constructions of laminated glass are most commonly specified for bomb-blast resistance. As with all laminated glazing, the glass can be supplied as tinted or reflective for light and solar control purposes. The lites of glass can be either annealed or heat-strengthened. Oldcastle BuildingEnvelope® does not recommend tempered laminated glass in this type of application. When insulating glass units are required for thermal performance, Oldcastle BuildingEnvelope® recommends that both lites of the IG unit be laminated in order to provide maximum protection for those both inside and outside the building. If only one lite in the IG unit is to be laminated, it must be the interior lite so as to protect the occupants of the building.  Oldcastle BuildingEnvelope®‘s blast-resistant laminated glass is an excellent glazing choice in all types of buildings that may be subjected to bomb blasts. The tough plastic interlayer holds the glass together after an impact, and with the proper framing systems, the glazing will be retained in the opening. Thus, the amount of flying glass, as well as the consequential injuries, can be dramatically reduced. The pressure from a bomb typically consists of a wave that rises almost instantaneously to a very high peak pressure that falls back to zero in a very short duration, as measured in milliseconds. For example, a 27 lb. bomb detonated from a stand-off distance of 48 ft. produces a peak pressure of 10 psi (1,440 psf) for 3.3 milliseconds. The area under the pressure time graph is called the impulse and is measured in psi-ms. Blast wave energy decreases very rapidly with distance so that the most effective protection is to increase this “stand-off” distance. However, this is not always a viable or economic option.