Fire Resistant Glass

Fire resistant performance and accreditation

Glasscraft are accredited Level 1 Attestation, also known as AoC level 1. This permits us to manufacture double glazed units with fire resistant performance. We can also supply single glazing for fire resistant applications.

There are different types of fire resistant glass offering different performance characteristics. It is essential to know the type of fire resistance required and the minimum time performance that it is being specified for.

‘E’ rated fire glass

Basic fire glass often has the letter ‘E’ before a number e.g E30. The ‘E’ signifies that the glazing is integrity only and the number is 30 minutes. This means that E30 glass will stay in one piece (retain its physical integrity) for a minimum of 30 minutes. The glass must be glazed correctly and this will give a 30 minute transparent barrier against flames, smoke and hot toxic gases.

Common E30 glass types are the GWPP clear wired glass and GWRC, obscure wired glass. See pictures to right.

EW rated fire glass

‘EW’ fire rated glass offers the same integrity characteristics as ‘E’ labelled fire glass but offers a limited degree of insulation against radiated heat. This is glass specific with many manufacturers not offering a value of this insulation. This glass looks like clear laminated glass. It will turn opaque when a fire occurs, signalling danger. This may be more appropriate for homes or installations that don’t want the wired glass due to aesthetics. It is similarly labelled to ‘E’ glass. e.g. EW30.

We stock EW30 in clear glass that is 7mm thick. This can be combined with other glass types to make sealed units or it can be used in relevant applications as single glazing.

EI rated fire glass

‘EI’ fire rated glass offers the best performance in the event of a fire. EI glass has integrity performance and insulation from radiated heat for a given time too. This means that for the specified times, the glazing will remain in one piece and also insulate the non-fire side of the glazing from the heat of the fire. This insulation is defined as the temperature on the non-fire side of the glass not exceeding 25°C within 1m of the glass surface, for the specified time. EI glass will also turn opaque in the event of a fire.

This can create an escape route that is both smoke and flame free and is at a temperature that doesn’t cause combustion. It is labelled similarly e.g EI 30/30 where the integrity is the first time figure and insulation is the second time figure.

These high performance EI glass types may also react with the UV light from the sun and if used in external positions, will need to be the internal pane with an outer laminated product.

With all fire rated products, it is not the glass alone that provides the protection. It is a combination of the frame, glazing method and glass that make up the protection specified. Wrong glazing materials or frame composition may result in hot gases and smoke being able to pass through the frame/glass structure and render the fire glazing useless. It is vital that all glazing is carried out to the prescribed method. See downloads on right.

Glass types

Clear Glass

GWPP Clear Wired Glass

Obscure Glass

GWRC Obscure Wired Glass