Glass
Laminated glass
Laminated glass is two or more panes bonded together with a plastic interlayer, usually PVB, to BS EN 14449. When struck it cracks, but the fragments stay stuck to the interlayer, so the pane stays in its frame and keeps the opening closed until it can be replaced.
Where does it work well?
Shop windows where you want the glass to stay in the frame after a break, stock display areas, overhead glazing and any frontage where an intruder should not get straight through after one blow.
Pros
- Holds together when broken
- Keeps the opening closed
- Can be cut to size
- Reduces UV light and some noise
Cons
- Heavier and thicker than a basic pane
- Exposed edges need protecting from moisture
- Costs more than annealed glass
How long does it last?
Typically as long as the frame, provided the edges are kept dry so that the interlayer does not delaminate.
What should you check when buying?
State the thickness, for example 6.8 mm or 8.8 mm, and the BS EN 12600 impact class needed. Confirm the frame rebate can take the pane, and check that sealants and gaskets are compatible with the interlayer, as some can attack it.
Common questions
Is laminated glass the same as toughened glass?
No. Toughened glass is heat-treated and breaks into small pieces, while laminated glass is bonded and stays in the frame. The two can be combined, with toughened panes laminated together for both strength and retention.
Does laminated glass stop a break-in?
It delays entry rather than stopping it. Standard laminated glass resists a single blow well, but a determined attack will get through. For a rated level of resistance, specify anti-bandit glass with a BS EN 356 class.