What Actually Is Laminated Glass?

What is Laminated glass?

Glass that has been annealed, toughened, heat soaked or heat strengthened – in any combination, that have been combined with an inter-layer to produce a product with modified characteristics (GGF Glazing Manual).

How is it different from other glass?

Laminated glass is more safe and secure type of glass. It consists of laminated sheet situated in between two layers of glass. Laminated sheet itself is usually made out of PVB (polyvinyl butyral). Easiest way to explain it is a jam sandwich. Glass panes are pieces of bread, inter-layer is a jam holding them together.

Well, that’s great. But what is PVB?

PVB is a resin mostly used for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility (wikipedia). It is an inter-layer bonding the glass panes.

Are there any other options than PVB?

Yes, of course. PVB is widely used, but that does not mean it is a singular inter-layer option. Others are EVA and SGP. You can read more about the differences here.

What makes it safer?

When you break glass, it shatters. When you break laminated glass, the PVB layers are working their magic, sticking glass layers to them. This makes the glass not to fall out of the frame. Also, it will not shatter. It will create a spider web-like pattern, keeping you safe from all the small shards piercing through skin.

On top of that, laminated type of glass is very resistant to harsh weather conditions, making it a very safe option for both, residential and commercial buildings.

That sounds great. Can it be modified?

Laminated glass can be manufactured to your liking. It can be straight, it can be curved, it can be transparent colour, white, brown, blue, etc.. It’s entirely up to you.

Is it same as toughened glass?

Toughened glass, also known as tempered glass, is a glass heated to very high temperatures and then cooled down rapidly.

Laminated and toughened glass are different. The easiest, although not the most practical way how to tell them apart is to break them. Laminated, as mentioned above, will create a spider web-like pattern, while toughened will shatter into small, but blunt pieces.

Broken Toughened versus Broken Laminated glass, photo from koalaglass.com.au

Does that mean that laminated glass is very thick?

Standard laminated glass is around 6.4mm thick. Compared to toughened glass, which is generally 4mm, there is only a small difference in thickness. But that small difference makes a massive impact on the safety of a glass. Laminated glass is called safety glass for a reason.

What are the main advantages?

Strength. It is very difficult to break, and even if you manage to break it, it does not shatter. This means you do not need to replace it often, as it is very resistant. It is engineer to withstand majority of impacts. If you throw a rock at your window with laminated glass, nothing will really happen. It takes a lot of strength and/or a massive impact to break it and make the spider web appear.

Security. As mentioned above, laminated glass is strong and durable. But what if someone breaks it? Will the thieves easily get into your house through your laminated glass balcony door? The answer is no. When laminated glass breaks, it breaks only on one side. The inter-layer will hold it together. Same goes with fire. The glass will not quickly disintegrate, so you have more time to get to safety. If there is an earthquake, the laminated glass will remain in place, giving you safer route to escape.

Where can I see laminated glass?

Due to laminated glass being widely used, you can spot it almost everywhere. The main uses are

  • car windshields
  • skylights
  • glass roofs
  • in the areas prone to natural disasters, such as earthquakes and hurricanes affected areas
  • aquariums
  • glass animal enclosures
  • windows and doors in high-risk areas
  • windows and doors in general
  • airport terminals
  • shop windows