Fire-rated Resistance Glazing/Glass

Fire resistance glass

Your personal bodyguard

Fire rated resistance glazing, doesn’t burn, and is tempered glass manufactured in various shapes and sizes used to retain and direct heat from a fire. Fire resistance glass typically forms a physical barrier to seal off an area and contain on one side smoke, fire and hot gases. Additional intumescent layers can often be applied to act as fire barriers by absorbing heat. Occupants on the non-fire side of fire glass are protected from fire effects such as burning.

Fire resistant glazing systems are becoming essential passive fire protection solutions in many modern building operations, retrofitting projects and construction applications. It offers regulated fire protection standards for building owners and architects and aesthetically pleasing features for designers. Furthermore, framing for fire resistant windows is constructed with either steel or timber – both of which have insulating capacities if designed and constructed correctly.

For fire rated glass in the use of window constructions, the Fire Resistant Rating (FRR) is used to classify the element’s fire rated performance through the following categories:

• Structural adequacy (R) – refers to the ability to maintain stability and adequate load bearing capacity as determined by NZS 4232 Part 2.
• Integrity (E) – is the glazing’s ability to resist the passage of flames and hot gases as specified in NZS 4232 Part 2.
• Insulation (I) – refers to the ability to maintain a temperature on the glass surface not exposed to the fire below the limits as specified in NZS 4232 Part 2.

Putting fire rated resistance glass to work

The most significant benefit of using fire rated resistance glass in your passive fire protection walls or systems is its transparency ability to show occupants the location of a fire while providing fire protection services and rescuers clear visibility to find people during a fire. New Zealand’s Building Code is very strict regarding fire resistant regulations, and PASSAFE Fire Protection are well and truly in support of that, particularly for glazing elements of fire protection. PASSAFE use only approved fire rated systems and design and construct glazing and window openings to specific regulations for your building. All window and glazing systems are rigorously tested, passed and installed with approved FRRs and authority regulations.

Types of fire resistant glass and glazing

Fire resistant rated glazings are characterised by two forms of product; insulating and non-insulating units. Both pertain to FRR regulations and must be tested in prototype form before implementation into any passive fire protection system. Both elements of fire resistant glass systems provide high levels of integrity and insulation to match safety glazing requirements. Protection levels are measured in defined time periods from 30mins up to 120mins.

Non-Insulated

Non-insulated fire resistant glazing can be recognised commonly by use of wired glass, that breaks upon exposure leaving wire to retain the glass fragments in place. However, it does not fit to Grade A safety glass NZ regulations.

Insulated

There are two types of insulating glass products:

• Intumescent interlayer glazing comprises a clear, heat absorbing layer, that once heated in excess of 120ºC turns into an opaque, insulating fire shield. The thicker the glass and the greater the number of interlayers, the higher the fire resistance rated will be.
• Glass which consists of a polymer heat absorbing gel, filled between two sheets of tempered glass, and interlayered glass in a sealed glazing unit.