How thick does glass need to be?

When sourcing glass for a building project, there are numerous things to consider. What style are you going for? Will the glass be decorated, tinted or frosted?

But as well as answering these questions, there's one crucial factor that you shouldn't overlook: thickness.

The thickness of glass is an essential consideration for several reasons. First, there are industry guidelines in place which need to be followed. Non-compliance can put you – and others – at risk. Then there are environmental, aesthetic and soundproofing aspects.

All of this is to say that the question "How thick does glass need to be?" is in the same ballpark as "How long is a piece of string?" It depends on where it's going to be installed along with a host of other factors.

Nevertheless, there are basic rules of thumb. Toughened glass, for instance, tends to be between four millimetres and 19 millimetres. Laminated glass is thicker – somewhere between 9.5 millimetres and 60 millimetres.

In this article, we're going to look more closely at the factors that determine how thick your glass should be.

But before we go any further, it's important to point out that nothing in this article should be taken as legal advice. You should always check your requirements against the relevant BS and EN guidelines.

General considerations

Minimum glass thickness will be stipulated by local or national government regulations and building codes. Following these is paramount. But as well as these bureaucratic considerations, there are several other factors to ponder before ordering glass for your project.

One is a matter of acoustics. As with other materials, the thicker the glass, the less sound can penetrate. If soundproofing is important to you, make sure you get a glass thick enough to block out unwanted noise.

Then there's the aesthetic side of things. Do you want the Apple-like sleekness of thin glass or something chunkier? How will your glass interact with its surroundings?

Energy efficiency has never been more important – and glass can play a significant role. If you're looking for ways to increase your thermal efficiency, thick glass can make a positive difference.

Finally, the weather conditions in your area are a factor when the glazing is external. Put crudely, a glasshouse on a mountaintop will need thicker glass than one in a valley. Make sure you take this into account when placing an order for your materials.

Partitions

When it comes to room dividers, the thickness of the glass will depend on the installation's surface area and load-bearing capacities. If a partition spans the length or width of an office, the glass will need to be on the thicker side, as glass thickness corresponds to stability and strength.

You need, of course, to make sure the partition is safe and in line with building regulations. There may be local or national government legislation and building codes to follow.

These regulations are much like GDPR and other types of compliance in the business world. They're there to protect your staff and visitors – but they're also there to protect you from any potential lawsuit that would arise if an accident were to happen.

However, these technical considerations will be taken into account alongside your aesthetic vision – and your budget. As with all interior design projects, compromise is all but certain. Your best bet is to consult a professional and get them to give you an estimate based on your specific requirements.

Walk-on glass for walkways and staircases

Once upon a time, walk-on glass was about as feasible as a porcelain hammer. Structural glazing is a recent phenomenon – for a long time, glass simply wasn't a material that could bear heavy loads.

Nowadays, financial districts and boutique hotels the world over like to install glass walkways and staircases. There are even lengthy glass bridges for tourists to marvel at (and walk on!)

Naturally, safety is of the essence when it comes to installations such as these. This is a key reason why laminated glass is used – a type of safety glass that's much, much stronger than an ordinary pane of glass.

Laminated glass is made out of two or more sheets of (often toughened) glass with a plastic interlayer in the middle. This means that it can withstand huge amounts of force – and when it does break, it will crack rather than shatter.

In the UK, you need to check the thickness of the glass against the relevant BS and EN frameworks. In domestic settings, the glass sheets must be a minimum of 25.5 millimetres thick – but in commercial locations, it could be more.

Security glass

There are plenty of settings where glass needs to be safer than safe. We're talking banks, galleries, jewellers' stores, airports and more. In these contexts, you need security glass – a laminated material that looks unremarkable enough but which offers robust protection against manual attack.

Security glass must be produced and installed in line with EN 365 standards. These provide an eight-tier scale of resistance from P1A all the way up to P8B.

As with most glass installations, the exact thickness needed will depend on the precise context and the level of security called for. As a general rule, however, anti-bandit glass is thicker than normal safety glass. Its thickened polymer interlayer means that thicknesses of 7.5 millimetres, 9.5 millimetres and 12.8 millimetres are common.

How we can help

Here at ToughGlaze, we can cut toughened glass to meet your exact requirements. All our glass is Kitemark-approved and we always act in accordance with BS and EN frameworks.

So whatever your project, and whatever thickness of glass you need, get in touch – we'll be happy to furnish you with the right materials for the job at affordable prices.

ToughGlaze has supplied high-quality glass products for more than 30 years. Our vision: to be the only supplier of toughened glass and laminated glass that our customers need to work with.