What is the advantage of a security interlayer in glazing?

Ionoplast interlayers for aluminium systems

There are many glazing options for aluminium window and door systems including double glazing, triple glazing and laminated glass, all of which vary in the level of security they provide. Some people may jump to the conclusion that double glazing is strong enough for their project, however, this may not be the case due to safety factors and building regulations.

Within the Building Regulations document N, there are requirements that need to be observed in order to maintain protection against potential glass breakages throughout both residential and commercial buildings. There are various locations within buildings that may be considered ‘critical’ in terms of the safety of the glazing system, this includes; the space between the finished floor level (FFL) and 800mm above that level on all internal and external walls including partitioning walls, in door or in side panels between FFL and 1500mm above this level.

Within document N there are rules about safe breakages and how robust the glass unit is, this includes the way in which the glass breaks. A safe breakage is defined by the result the glass shows up during impact testing, therefore if glass breaks within a property it must be limited to creating only a small opening that is clear with limited detachable particles and no sharp or pointed edges to the glass.

It is important to understand the types of glass available for glazing systems and how they vary. Float glass is a type of glass that was commonly used within glazing prior to the introduction of toughened and laminated glass. Float glass is still used within some double-glazed units however when these systems break due to impact, they will shatter into sharp-edged openings which are dangerous for the occupant. Toughened glass is a safer option as this shatters into many small rounded or cuboid-shaped pieces due to the stress lines created in the glass when it goes through a heat soaking process to enhance its strength.


Laminated glass is one of the strongest forms of glass available for use within aluminium glazing systems. It is created using an Ionoplast material that is laminated between two or three panes of glass (depending on the desired glass specification for the glazing) to create a strong, bonded glass unit. Laminated glass is used to strengthen the glass units within aluminium glazing systems to ensure that building regulations are met and that the unit offers high levels of security, both to the occupant if a glass breakage were to occur but also security against a break-in


What are the advantages of laminated glass?


Due to the strength of the glass from the bonded interlayer(s) the time it takes to break through a glass pane is increased as when the glass is broken it is held together like a film (similar to how car windscreens break during road traffic collisions), this means that the thief will have to spend a longer amount of time trying to push the glass out of the aluminium framing, instead of being able to quickly knock all glass shards out of the frame like float glass.


Laminated glass also helps to protect the occupants from injury in a safer way than toughened glass, this is because the shattered glass is held together by the Ionoplast interlayer rather than pieces of glass shattering into the internal rooms which therefore reduces the risk of injury.

By using a high-performance Ionoplast interlayer, the thickness of the glass can usually be reduced, resulting in thinner and slimmer installations that wouldn’t be possible with standard toughened glass.

Laminated glass is ideal for the Sieger® Balustrade system and if the glazing incurs a breakage the glazing will not shatter and spill over the floor, balcony or ground below as it will be held together by the interlayer and further supported by the handrail on this system.

To discuss specifying a security interlayer within the glazing on your projects, speak to a member of the Sieger® team who will be able to provide you with further technical information and advice about your project.


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