Tempered glass is most often the recommended glazing type in fire station overhead doors. Tempered glass is a type of safety glass and will break into small, square pieces when broken. This feature makes it less likely to lacerate an individual that comes into contact with the broken pieces. Tempering glass involves the use of chemicals in conjunction with heat to strengthen the unit. Tempered glazing can be clear, frosted, tinted, insulated, back painted, or colored.
Annealed glass – or as it is often called in the garage door industry D/S glass is not considered a safety glazing like tempered units. Unlike tempered glass, traditional annealed glass will break off into large, sharp shards when broken which can be dangerous. Care and consideration should be taken when choosing locations to install annealed glass.