Improve security against intruders and blasts

Introduction to safer

It seems that nearly every day we hear stories of break-in’s and threats of terrorism. It is unnerving and affects all of us, as we could all be at risk. Selectaglaze secondary glazing can provide an unseen level of security to any property. It creates a second barrier of protection from the inside that can prevent the most determined thief or protect the occupants from the effects of bomb blast.  You may be looking to find ways to secure the contents of your building; be it physical high value objects or highly sensitive data or the people within. If this is the case, secondary glazing could provide the solution.

Safer

Benefits of security secondary glazing

  • Deters intruders
  • Blast mitigation
  • Protection against firearms
  • Preserves clean environments
  • Second barrier to entry
  • Removes the need for unsightly grilles
  • Maintains a normalised environment
  • Provides a delay mechanism

How it works

Physical attack

Under physical attack secondary glazing works by providing a second barrier to entry. At lower risk levels it must prevent manipulation of the locks and catches or removal of the glass or glazed panels. As the performance increases it must resist levering or use of cutting tools including penetration of the glazing, which at higher risk levels will be a sophisticated combination of glass, resin and polycarbonate. It is also worth noting that the attacker will have to break through the primary window first then work through the breached opening to attack the secondary glazing, by which time any vibration alarms will have been activated. 

Blast mitigation

Secondary glazing can protect occupants and contents from the effects of an explosion by containing the flying shards of glass from the breakup of the primary window under the blast load. Fixings, frame, locks and glass are all designed to work in harmony deflecting and yielding to absorb the blast wave. PVB interlayers are used in the laminated glass composition to stretch and contain the blast.

Ballistic

Protection from firearm attack is achieved by several layers of glass of various thicknesses laminated together. The front layers of glass are designed to shatter, thereby absorbing the initial impact energy, subsequent glass and interlayers absorb the lower level shock waves. Lighter, thinner bullet resistant glass can be produced by the use of polycarbonate in the lamination. However, bullet resistant glass is not enough on its own as the same performance is required from all the components of the frame including any joints and junctions.

Fire

Fire resistant glazing provides a protected escape route for occupants. Specialist glass, together with fire and intumescent seals set within appropriate framing, resists the intense heat of a fire. This provides "integrity" which prevents breach of flames and gases, and where required "insulation" to reduce the transfer of heat.

Clean environments

Secondary glazing with its high-performance seals and easy clean surfaces can provide an efficiently sealed envelope in clean, antibacterial and positive or negative pressured environments. Fitted on the inside of primary windows or in partitions, it can be used to stop the ingress of dust and grime and provide a protected space for blinds.

Guidance and regulations

Physical attack

Guidelines include:

  • PAS 24:2012 – This standard simulates forced entry by the use of static loading as well as manipulation using simple tools. The test does not involve glass breakage and so replicates a stealth attack
  • LPS1175 – Developed by the Loss Prevention Certification Board the standard deals with the elements of the building façade such as doors, widows, grills and enclosures. There are eight levels of resistance measured in terms of attack tools and time
  • Secured by Design – Is a crime prevention initiative owned by The Association of Chief of Police Officers. Products successfully tested to PAS 24 are awarded a “Police Preferred Specification”

Risk levels

  • Low - Guarding against an opportunistic attack by a thief who wants to work quickly and with the minimum chance of detection, secondary glazing can be used to provide an additional barrier to entry with simple locks and toughened or laminated glass. There are no test standards at this level
  • Medium - To guard against a more determined attack by a thief who will be prepared to spend more time attacking a frame, but may not break the glass as this will attract attention. Secondary glazing tested to the security element of PAS 24 and certified to Secured by Design is recommended
  • High - Guarding against an attack which is planned and very aggressive, where both the frame and glass will come under determined attack, then products certified to LPS 1175 are recommended

Product selector

Test Standard Rating Level Horizontal Sliding Vertical Sliding Hinged Fixed Demountable fixed Product Glass Options (mm)
PAS24:2012 (security requirement) Secured by Design Single Level     x     S45 SHC  6.8
      x   S46 FL  6.8 7.5 9.5 11.5 11.3       
x         S80 2HS
  x        S90 VSCB
    x     S41 SHC
    x     S50 SHC
      x   S40 FL
      x   S42 FL
LPS 1175 SR1 x         S85 2HS 12.04     
  x       S95 VSCB
    x     S50 SHC
      x   S50 FL
        x S43 DFL
        x S55 DFL
LPS 1175 SR2 x         S85 2HS 12 Tecdur 12.4 GPG      
  x       S95 VSCB
    x     S50 SHC
      x   S50 FL
        x S43 DFL
        x S55 DFL
LPS 1175 SR3         x S55 DFL  12 Tecdur 
GPG – specialist glass/polycarbonate/glass laminate
Tecdur – specialist glass/polycarbonate laminate (glass face to room)

Blast mitigation

Guidelines include: 

  • ISO 16933 - Measures the effects of explosive devices of varying sizes at a number of distances. 100kg of explosive is used to replicate a vehicle bomb, starting at 45m distance (rating EXV45) reducing to 33m, 25m, 19m, 15m, 12m, and 10m (rating EXV10).

Risk levels

The following is for guidance only and a full risk assessment by a security advisor is recommended.
  • Low - The building is unlikely to be a direct target but is in commercial or public use and there exists a duty of care, or it may be a government building where a minimum requirement exists. EXV 45 should be considered.
  • Medium - The building is unlikely to be a direct target but is close to a sensitive building which is considered to be a target. EXV 33 should be considered.
  • High - The building is a potential direct target on account of usage or ownership. EXV 25 or higher should be considered.

Product selector

Test Standard Rating Level Horizontal sliding Vertical sliding Hinged Fixed Demountable fixed Product Glass Options (mm)
ISO 16933    EXV45
(low hazard at 45m)
 x         S10 2HS 6.8
   x       S20 VSCB
     x     S45 SHC
       x   S46 FL
 ISO 16933      EXV33 
(low hazard at 33m)
 x          S80 2HS 6.8     
   x        S90 VSCB
     x      S41 SHC
       x    S40 FL
       x    S42 FL
 ISO 16933        EXV25
(low hazard at 25m)
 x          S85 2HS   9.5/11.5T
   x        S95 VSCB
     x      S50 SHC   9.5/11.5
       x    S50 FL
       x    S42 FL 9.5T/11.5T  
         x  S43 DFL
         x  S55 DFL  9.5/11.5
ISO 16933   EXV15 
(low hazard at 15m) 
         x  S55 DFL  15.04
Blast ratings against 100KG TNT equivalent T = Toughened Laminate; Tecdur = specialist glass/polycarbonate laminate (glass face to room)
When using Tecdur it is recommended that UV protection film is applied to the external glass

Ballistic attack

Guidelines include: 

  • EN 1522/1523 - This standard measures the resistance to penetration of the glass and the framing against various rounds. It has eight levels of certification covering handguns, rifles and shotguns.

Product selector

Test Standard Rating Horizontal Sliding Vertical sliding Hinged Fixed Demountable Fixed Product Glass options (mm)
EN 1522
EN 1523 
FB4         x  S55 DFL  22GP
GP – specialist multiple glass/polycarbonate laminate

Fire resistance

Guidelines include: 

  • BSEN 1363-1, BSEN 1364-1 tests the fire resistance of non-load bearing elements of the building. 

Product selector

Test Standard Rating Horizontal sliding Vertical sliding Hinged Fixed Demountable fixed Product Glass options (mm)
BSEN 1363-1
BSEN 1364-1 
30 minute integrity       x   S40 FL 10 PyrodurTM
Pyrodur™ - Pilkington fire glass