Are glass balustrades safe?

As a modern alternative to wood and other opaque building materials, glass balustrades have quickly gained popularity in offices, homes, and commercial spaces alike.

There’s no doubt that they offer an aesthetically pleasing design, improving the sense of space with uninterrupted views and increased natural light. However, some people might be wary of choosing glass balustrades due to concerns about their safety.

Since ordinary glass has a reputation for being fragile, and easily shattering into sharp pieces that can cause injuries, it’s understandable to worry about using glass panels as safety barriers. You don’t have to worry, though, as glass balustrades use a stronger type of toughened glass.

Not only this but there are also strict regulations for the design and installation of glass balustrades, ensuring that they’re completely safe for public and private use.

Forget the myths you may have heard about glass balustrades breaking easily – here’s the truth about how and why it’s safe to install glass balustrades.

Safe glass balustrade design

Any balustrade system using glass balustrade panels must comply with Building Regulations and British Standards, which specify the minimum requirements for their legal usage. Approved Document K and BS 6180:2011 define the type of glass, height, thickness, loads, and more that should be used in different settings to make the glass balustrades safe.

• Glass type

In order to be considered safety glass, it has to be tempered to form toughened glass. This involves heating and rapidly cooling the glass to lock in higher tension, which makes the panel several times stronger. This makes the glass harder to break, and if does shatter, it will form blunt pebble-like pieces rather than harmful shards with sharp edges.

To make a glass balustrade even stronger, two panes of glass can be sealed together with an interlayer to form laminated glass. If one or both panels break, the interlayer will hold the pieces in place to prevent the glass from shattering everywhere, maintaining the barrier.

All glass balustrades must be made from either toughened glass, laminated glass, or toughened laminated glass, with thickness requirements determined by where they’ll be installed.

• Glass thickness

A single layer of the toughened glass must be at least 10mm thick in order to be used for a glass balustrade. When the toughened glass panels are the minimum thickness, a framing system such as steel posts and handrails is required to maintain a barrier if the glass breaks.

For frameless glass balustrades, which opt for minimal visible fixings to achieve a more seamless look, the glass should be at least 15mm thick. If the potential fall height is more than 600mm but you don’t want a handrail, you must use toughened laminated glass panels.

In some cases, such as more intense structural applications, toughened laminated glass can be up to 21.5mm thick for ultimate reinforcement.

• Glass height

The height of glass balustrades is also regulated according to where they’re fitted. For example, seating areas with balustrades surrounding them must be 530mm tall or more if the seating is fixed, and at least 800mm tall if it isn’t.

When it comes to internal staircases, landings, or mezzanine floors, the balustrades must be at least 900mm high. When used externally for balconies, stairs, or rooftops, the balustrades need to be a minimum of 1100mm high.

These heights are measured from the finished floor level, and do not include any recessed parts. Each glass panel should be no more than 1.1m–2.4m wide for testing purposes, and must not have gaps more than 10cm wide between them.

• Load requirements

Glass balustrades have to be thoroughly tested to determine how much pressure they’re capable of withstanding before the glass panel fails. There are several different types of loads they need to be tested for, including (but not limited to):

• Line load – Horizontal force at the top, such as a person leaning on the balustrade. Measured in kilonewtons per metre (kN/m).
• Concentrated load – Horizontal force such as sudden human impact from a person falling against the balustrade. Measured in kilonewtons (kN).
• Uniformly Distributed Load (UDL) – Horizontal force uniformly applied across the midsection of the balustrade. Measured in kilonewtons per square metre (kN/m2).

The minimum requirements for glass balustrade loads are covered in BS EN 1991-1 (Part 1 and Part 4), with standardized impact tests explained in BS EN 12600:2002.

Installing glass balustrades safely

There are many styles of glass balustrades, with different ways to install them. It’s common to see a glass balustrade with stainless steel posts and handrails, for example, or a frameless style secured in the ground using a recessed channel. Or the design could be somewhere in the middle, with a handrail and corner posts but a channel profile installation.

There are also different options for glass balustrade fixings, such as rounded or square glass clamps, inline fittings, and glass-to-wall fittings. These often come in either polished metal or brushed metal finishes, depending on the final look you’re going for.

The installation method you want to use will depend on where you want to install the glass balustrades and the type of glass you’re using. The British Standards mentioned above stipulate that you must have a handrail system if there is a drop of 600mm or more between floor levels.

The only exception to this is when the balustrades use toughened laminated glass, which is typically at least 13mm thick. This type of glass is suitable for frameless and handrail-less installations because it’s very difficult to break and doesn’t fall to pieces even if it cracks.

For commercial settings, it’s best to hire a professional to install glass balustrades for you. There is likely to be higher traffic in these areas which requires stronger structures and experience in fitting such systems properly. For residential settings, it’s possible to DIY the installation – but it’s not necessarily easy, and you should do a lot of research first to make sure you get it right.

Glass balustrade maintenance

Conveniently, glass balustrades don’t require a lot of work to keep them in good condition. They’re easy to wipe clean as needed, and can otherwise be left to do their jobs without intervention. That said, regularly checking over the balustrades is essential to make sure everything is as it should be.

Forces such as the weight and vibrations of people leaning on the balustrades, pulling at the handrail, and walking up and down can gradually cause movements so small they’re visually undetectable, so it’s worth checking that nothing has come loose. This should be required more frequently in settings with higher foot traffic.

Similarly, external glass balustrades will be exposed to the elements, and harsh weather can eventually cause wear and tear. While these materials aren’t susceptible to damp and rot like wood is, even corrosion-resistant metal has the possibility of rusting over time.

Are glass balustrades safe for everyone?

As you now know, glass balustrades are completely safe when designed, fitted, and used in the right way. The super-strong glass is tough to break, and the way the system is designed will ensure that people are still protected even in the glass is compromised by an unusual impact.

Their high durability means that glass balustrades will last for a very long time without degrading in strength or quality. The strict requirements for their design, with minimum heights and restricted gaps, mean that glass balustrades are also safe to use around small children and pets.

If you’re thinking about installing them on your property, but have further concerns or questions about the safety of glass balustrades, you can contact your local Building Control office to learn more about the requirements for your planned application.