This guards against an opportunistic attack by a thief who wants to work quickly and with the minimum chance of detection. Although there are no test standards at this level, a simple secondary window incorporating a lock and toughened or laminated safety glass acts as a deterrent by creating an additional barrier to entry that is both visual and physical.
This covers a more determined attack. The thief will be prepared to spend more time attacking a frame, but may not break the glass as this will attract attention.
The window frames and locks need to be robust and tested in accordance with BS7590. BS7950 is a standard for primary windows which includes tests for both weathering and intruder resistance. Weathering tests are not relevant to secondary glazing, but products can be tested against the security requirements of BS7950 and accredited to Secured by Design.
Selectaglaze recommends a minimum 6.8mm laminated glass tested to BS6206 Class A. If the risk of glass breakage is higher, Anti-Bandit laminated glass tested to BS5544 or BSEN 356 should be considered. There is a choice of 7.5mm, 9.5mm and 11.5mm 3-ply laminates or, for optimum protection at this level, 11.3mm 5-ply laminated glass.
The building is a known risk and any attack will be planned and very aggressive. Both the frame and glass will come under determined attack with a range of tools.
Products should be specified that are certified to the LPS1175 standard and listed in the Red Book. The standard has a number of increasingly challenging test levels. Tools for level 1 include a screwdriver, lever, pliers and knife and the test duration is ten minutes with an actual attack time of one minute. This rises to a 20 minute test time and 5 minutes attack time at level 3 with tools such as a claw hammer, small axe, battery drill and a 700mm long crowbar. Frames must be very strong with significant locking to opening panels and specialist laminated glass will be required.
These certified products can be used in place of security grilles, gates and bars providing peace of mind without the visual intrusion.
See our chart to select the right security product for your application
Results of security testing
Protection against Ballistic Attack