Safety Glass is required in:
Critical Safety Areas
1. Critical Safety Areas. The areas of internal and external walls which are considered ‘critical locations’ in terms of safety are:
1.1 Between the finished floor level and 1500mm above that level in doors, and in side panels which are within 300mm of either edge of the door.
1.2 Between the finished floor level 800mm above that level in the case of walls, partitions and windows. 2. Requirements of BS 6262 Part.
2.1 Safe Breakage: For doors and door side panels, the glazing used should not break, or should break safely in accordance with Class C of the standard impact test BS 6206(1981) if 900mm wide or less, or Class B if wider than 900mm.
For other low level glazing the pane should comply with at least BS 6206 Class C.Use laminated or toughened glass, or plastics glazing sheet, or wired glass, that meet BS6206, or glass with plastic film applied so the pane of glass with film meets BS6206.
For unbacked mirror glazing accessible to impact from one side only, the pane should comply with BS 6206 Class C0 if equal to or less than 900mm wide or Class B0 if wider than 900mm.Unbacked glazing either has no backing behind which does not retain its integrity or is cracked or broken when tested as described in BS 7449 (1991): Appendix A.If the mirror glazing is fully backed by a solid material, like a wall or timber wardrobe door and it is securely fixed so that there is space of no more than 25mm between the mirror and the backing material, then a glass which does not comply with BS 6206 may be used .
2.2 Small Panes: Ordinary annealed glass may be used in small panes up to a maximum width of 250mm and an area not exceeding 0.5m2. Such glass must no be less than 6mm in thickness, expect in the case of traditional lead lights and copper lights, where 4mm can be used.
2.3 Robustness: Robustness refers to the strength of the glazing forming fronts to non-domestic buildings such as shops, showrooms, offices, factories and public buildings. Some glazing, such as polycarbonate, is inherently strong. Annealed glass, that does not normally comply with BS 6206, can gain robustness with increased thickness. Annealed glass may only be used in critical locations, therefore, when the nominal thickness and dimensions are as listed in the table below.
Nominal Thickness (mm) Max pane Size Dimensions( mm) 8 1100 x 1100 10 2250 x 2250 12 BS 6262 Pt 4 4500 4500 Document N 1992 3000 x 4500 15 or Thicker No Limits
Laminated Safety Glass is the only glass combining both safety and security properties. It consists of 2 or more sheets of ordinary glass, sandwiched together by a PVB (polyvinyl butyral) interlayer. Should the glass be broken, the shards will remain adhered to the interlayer, reducing damage to both property and people. Recommended for areas which are subject to Regulation 14 and document N.
Toughened glass is 5 times stronger than annealed glass. If attacked it will disintegrate into small pieces with dulled edges, thus reducing the risk of injury. Toughened glass is cut to size before the heat treatment process.
Toughened Glass Assemblies
Frameless all glass entrances, including side panels and transoms, allows freedom to create many design options. A comprehensive range of rails and patch fittings are available in a variety of finishes, including anodised and powder coated. Available in 10mm or 12mm.
RECOMENDATIONS FOR INSTALLING LAMINATED GLASS IN SHOP FRONTS – THICKNESS CONFIGURATION BRITISH STANDARD REACHED
7.5mm (3PLY) 3mm g x 1.52mm pvb x 3mm g Safety and security glass BS5544 – Anti-bandit glazing
8.8mm (3PLY) 4mm g x 0.76mm pvb x 4mm g Safety and security glass BS6206 – Class A
9.5mm (3PLY) 4mm g x 1.52mm pvb x 4mm g Safety and security glass BS5544 – Anti-bandit glazing
10.8mm (3PLY) 5mm g x 0.76mm pvb x 5mm g Safety and security glass BS6206 – Class A
11.5mm (3PLY) 5mm g x 1.52mm pvb x 5mm g Safety and security glass BS5544 – Anti-bandit glazing
From 23mm (multi-ply) on application BS 5051 – Bullet resistant glazing
Fire Resistant Glass
Integrity glasses provide a specific resistance to the passage of smoke and fumes, though they will permit the transmission of heat radiation from a fire. This range of fire retardant glass is produce by changing the raw material composition, by laminating or specialised modifications of toughened glass. Wired glass provides inherent fire-resistant properties. Insulated plasses are generally made up of multi layers of glass and clear intumescent inter-layers. When subjected to heat above 120 degrees centigrade, the inter-layers expand forming a white foam. It is this foam that provides the glass with insulating properties, preventing heat transmission.