Both laminated glass and toughened glass are commonly used in glazing to provide protection from and in cases of glass breaking. But they do have their differences.
By Larry Bohan on 19 September 2018
Laminated glass and toughened glass. They are frequently mistaken for one another and confused as being one and same product. They’re not.
While both are types of safety glass and are superior to standard glass, laminated glass and toughened glass differ from each other significantly in a number of areas.
Similar in thatboth offer better protection against break-ins, flying objects and severe winds when used on home interiors, laminated glass and toughened glass each defend properties in their own unique way, primarily in how they react when shattered.
In this blog we will explain the core differences between laminated glass and toughened glass, from themanufacturing processto how each reacts upon impact.
Knowing the difference between these two types of safety glass will give you a better understanding of which can offer suitable security for your windows, doors and rooflights.
What is Laminated Glass?
Laminated glass is most known for being used on the windscreensof the majority of the world’s cars. This globaluse can be put down to what happens when laminated glass shatters.
When smashed, laminated glass holds in place and does not break up into large jagged shards or hundreds of little pieces. Instead, it keeps in place long enough for a replacement to be found.
This happens thanks to the plastic (polyvinyl butyral) interlay that is sandwiched between two glass sheets during manufacture. Thisbonds the two panes together like a glue so thateven when the glass breaks, its fragments keep binding on the thin film.
This highly practical safety feature greatly reduces the chances of injury occurring from falling glass.
In addition to this, as the panes do not burst apart on impact, laminated glass leaves no hole behind for intruders and thieves to crawl through.Laminated glass also offers far superior UV resistance and sound proofing to annealed glass.
There are several different types of laminated safety glass built to withstand a specified level of attack. These include for blast-resistance glass, fire-resistance glass, bullet-resistance glassand solar control laminated glass.
What is Toughened Glass?
Toughened glass, also known as tempered glass after its method of production, is a type of safety glass that is five times stronger than annealed and laminated glass of the same size and thickness.
Toughened glass gets this strength from the tempering process which sees it subjected to intense heating followed by rapid cooling during manufacture.
This toughness gives tempered glass a far higher load and breakage resistance. Toughened glass needs to be hit a lot harder than other safety glass in order to break.
Whereas laminated glass holds in place when shattered, toughened glass breaks up into hundreds of tiny pieces. You will probably have seen this on the floor where a telephone box or bus stop hadbeen vandalised.
This method of breaking lowers the risk of injury compared to annealed glass which breaks up into larger, jagged pieces more likely to injure anybody in close proximity.
Tempered glass has a heat resistance four to five times stronger than standard glass and can withstand high temperature changes up to 250°C.
Toughened Glass vsLaminated Glass- Which is Better?
The question of whether to opt for toughened glass or laminated glass on an application does not have a definitive answer. Except for when its glaringly obvious, i.e. on a car windscreen,it's usuallydown to personal preference.
If comparing the two on security, toughened glass is the stronger glass and requires far greater force to be shattered. However,when it does, the area the glass was protecting is leftexposed.
This is far less of a worry with laminated glass, as the glass stays in place when shattered. However, as laminated glass is not as resistant to breakage as tempered glass, accidental impacts, such as a stray ball or other flying object, are more likely to cause the glass to break and therefore need replacing.
Some people prefer laminated glass on overhead glass structures just in case the glass does break and rain down in tiny pieces. When this happens, finding a replacement window or replacement glass is also far more urgent a matter for obvious reasons.
Others will argue thattoughened glass is still the safer option as the likelihood of it shattering is far less likely, while the tiny fragments of glass that do rain down are not sharp or jagged andtherefore unlikely to cause serious injury.
On price, toughened glass is the cheaper option on a like-for-like basis and is the more likely of the two to be offered as standard. Where sound reduction and UV resistance areconcerned, laminated glass generally offersgreater protection than toughened glass.
What we Offer at Sterlingbuild
Many of the brands we sell at Sterlingbuildincorporate both types of safety glass in their products by combining a laminated inner pane with an outer toughened pane in a 'best of both' design.
Both ECO+ and the VELUX Groupoffer this on theircentre pivot pitched roof windows as standard. ECO+ also offers this dual glazing acrossits flat rooflight range.
RoofLITE prefers toughened glass only on its roof windows, as do REAL on its collection of aluminium bifoldsandaluminium sliders.
Made to measure services, such as what we offer on our Korniche roof lanterns and Signature flat glass rooflights, can be customisedwith any internal/external combination of laminated glass and toughened glass.
