Glass for a glass balustrade is chosen based on the balustrade system’s design, glass dimensions, fixings and the safety function the glass needs to provide. Common options are 8.76 mm laminated safety glass, 8.76 mm toughened laminated glass and, in systems that require it, 12.76 mm toughened laminated glass. You then choose clear, ultra-clear, opal, grey or coloured glass based on views, light, privacy and look.
So the right glass thickness is not decided only by how substantial you want the glass to be. Lamination helps the glass hold together when it breaks, while toughening changes the mechanical properties and breakage pattern of the pane. The glass, fixings and other parts of the balustrade must therefore be assessed as one structure.
In this guide we compare 8.76 and 12.76 mm glass, standard laminated glass and toughened laminated glass, and clear, ultra-clear, opal, grey and coloured glass. You will also learn how the glass is made, how the edges are finished, which glass types are available and how to choose the right glass for your glass balustrade.
Which safety glass is used in a glass balustrade?
A glass balustrade uses safety glass chosen for the function the glass needs to serve. Laminated safety glass can hold together when the glass breaks, while thermally toughened safety glass breaks into many small fragments. Toughened laminated glass combines toughened glass panes with a laminating interlayer.
When the glass is to protect against falls, it is not enough to choose the glass type based on the breakage pattern. The glass and fixings together must be sized for the impacts and loads that can occur, or be supplemented with other fall protection. The glass must therefore always be assessed as part of the whole glass balustrade, together with the balustrade system, glass dimensions, fixings, position and drop height.
The breakage pattern should limit the risk of cuts
When it breaks, thermally toughened safety glass shatters into many small fragments instead of large sharp shards. Laminated safety glass works differently: the interlayer helps hold the glass fragments in place when one or more panes break.
Glass and fixings must work together
When the glass forms part of fall protection, the glass and fixings together need to withstand the impacts and loads that may occur. Laminated safety glass is one example of glass that can hold together after breaking and so help prevent falls through the glass.
What is 8.76 mm laminated glass, and when is it suitable for a glass balustrade?
8.76 mm laminated glass is a laminated safety glass with two 4 mm panes and a 0.76 mm interlayer. It is suitable for glass balustrades where the balustrade system is designed for 8.76 mm laminated glass and where the glass dimensions, fixings and loads are within the system’s sizing.
The interlayer bonds the glass panes together and helps hold the fragments in place if one or more panes crack. The glass thickness should therefore not be chosen in isolation: the same 8.76 mm glass can have different conditions depending on its width and height, how it is fixed and what load the whole glass balustrade needs to withstand.
The first glass pane in the laminate.
Bonds the two glass panes together.
The second glass pane in the laminate.
4 mm glass + 0.76 mm interlayer + 4 mm glass results in a total glass thickness of 8.76 mm. However, this does not mean that 8.76 mm is the right choice for all glass balustrades – the balustrade system, glass dimensions and fixing must always be evaluated together.
When is 8.76 mm toughened laminated glass suitable for a glass balustrade?
8.76 mm toughened laminated glass is suitable when the sizing of the balustrade system specifies that the laminated panes should be toughened. This may apply depending on glass dimensions, fixings and the load the structure needs to withstand, but toughening should not be chosen separately from the rest of the glass balustrade.
The glass has the same nominal thickness as standard 8.76 mm laminated glass and consists of two 4 mm glass panes with a 0.76 mm interlayer. The difference is that both glass panes are toughened before they are laminated, which alters their mechanical properties and fracture pattern, while the lamination helps the glass hold together after breakage.
Two glass panes with an interlayer
Standard 8.76 mm laminated glass consists of two 4 mm glass panes laminated together with an interlayer. The lamination helps keep the glass fragments in place if one or more panes break.
The same laminated construction using toughened glass panes
In 8.76 mm toughened laminated glass, both 4 mm glass panes have been toughened prior to lamination. Toughening alters the glass panes’ strength and fracture pattern, while the interlayer still helps the laminated glass hold together after breakage.
When is 12.76 mm toughened laminated glass needed in a glass balustrade?
12.76 mm toughened laminated glass is used when the sizing of the glass balustrade requires thicker glass than 8.76 mm. This may apply to larger glass panels, balustrade systems where the glass carries a larger share of the structural function, or where the loads on the balustrade require a stronger glass make-up.
The glass consists of two toughened 6 mm panes with a 0.76 mm interlayer. The right thickness is not decided by the glass dimensions or drop height on their own, but by how glass dimensions, fixings, balustrade system and loads work together.
Larger glass panels may require thicker glass
The width and height of the glass affect how the pane is loaded. Therefore, as the glass panel becomes larger, a different glass thickness may be required than for a smaller section, depending on how the glass is supported and fastened.
Glass and fixings are designed together
In frameless glass balustrades, for example, the glass and the continuous fixing play a greater structural role. The glass thickness therefore needs to follow the sizing for the balustrade system and the chosen fixing.
Location and intended use affect the requirements for the balustrade
A glass balustrade can be subjected to various loads depending on where it is placed and how the environment is used. This does not mean that a 12.76 mm thickness is automatically required in a particular location – the entire structure must be designed to withstand the specific load.
12.76 mm is not a general requirement for a particular setting or drop height. This thickness is used when the sizing of the balustrade system, the glass dimensions, the fixings and the loads together require the stronger glass make-up.
What is the difference between 8.76 mm and 12.76 mm glass in a glass balustrade?
8.76 and 12.76 mm differ in both thickness and make-up. Standard 8.76 mm laminated glass consists of two non-toughened 4 mm panes, while 8.76 mm toughened laminated glass has two toughened 4 mm panes. 12.76 mm toughened laminated glass is made of two toughened 6 mm panes.
Thicker glass is not automatically the right choice, though. Glass thickness and type must follow the sizing of the balustrade system and be assessed together with the glass dimensions, fixings and the load the whole glass balustrade needs to withstand. The table shows the main differences side by side.
| Property | 8.76 mm laminated glass | 8.76 mm toughened laminated glass | 12.76 mm toughened laminated glass |
|---|---|---|---|
| Construction | 4 mm glass + 0.76 mm interlayer + 4 mm glass | 4 mm toughened glass + 0.76 mm intermediate layer + 4 mm toughened glass | 6 mm toughened glass + 0.76 mm interlayer + 6 mm toughened glass |
| Glass panels | Non-toughened | Toughened | Toughened |
| On breakage | The glass panes crack, and the fragments are held in place by the laminate | The toughened panes fragment and are held in place by the laminate | The toughened panes fragment and are held in place by the laminate |
| Glass thickness | 8.76 mm | 8.76 mm | 12.76 mm |
| When applicable | When the balustrade system is designed for 8.76 mm laminated glass | When the system's design requires or specifies toughened 4 mm glass panels | When the system's design requires a thicker glass assembly, such as in the case of larger glass panels |
| Edge Finishing | Ground and polished edges | Edges ground and polished before toughening | Edges ground and polished before toughening |
| Colour Options | Clear, ultra-clear, opal, and grey | Depends on the type of glass and configuration selected | Depends on the type of glass and configuration selected |
How are laminated and toughened glass for balustrades manufactured?
Laminated glass is made by bonding two glass panes together with a laminating interlayer, while toughened glass is first cut and edge-finished and then heat-treated and rapidly cooled. When toughened laminated glass is made, the panes are therefore toughened before lamination.
These processes serve different functions. Laminating helps keep the glass panes and fragments together after breakage, while toughening alters the mechanical properties and fracture pattern of the glass panes. Therefore, dimensions, edges, and any holes must be finalised before the glass to be toughened moves on to the next stage of the process.
How laminated glass is made
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Glass panes are cut to size and their edges finished
The two glass panels are cut to their final dimensions. The edges are ground and polished before the panels move on to the lamination process.
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The interlayer is placed between the glass panes
A laminating interlayer is placed between the panes of glass. The interlayer later helps to hold in place glass fragments if one or more glass panels shatter.
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Glass and the interlayer are bonded together
The glass panes and the interlayer are pressed and treated so that the layers bond together into the finished laminated glass pane.
Toughening takes place before lamination
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The glass is fully processed first
Dimensions, edges, and any holes are finished before toughening. After heat treatment, the glass sheet cannot be cut or drilled in the usual way.
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The glass panes are toughened
The glass is heated and then rapidly cooled. This process changes the mechanical properties of the glass pane and how it shatters if it breaks.
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The toughened panes are laminated
After toughening, a laminating interlayer is placed between the panes and the layers are bonded together into finished toughened laminated glass.
How is grey, opal, and coloured laminated glass made?
Grey, opal and coloured laminated glass get their look in different ways. In grey laminated glass the tint is in the glass panes themselves, while opal glass gets its milky look from the interlayer. Coloured laminated glass is instead made with coloured interlayers between clear glass panes.
The difference, then, lies in which part of the laminate gives the glass its colour or opacity. The glass surface is not painted afterward; rather, the appearance is created as part of the glass’s structure.
- Grey glass
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The tone comes from the glass panels themselves
Grey laminated glass is made of grey-tinted glass panes with a clear laminating interlayer. The panes provide the grey tint, while the interlayer bonds the glass together.
Grey-tinted glass + clear intermediate layer + grey-tinted glass
- Opal glass
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The interlayer creates the milky character
Opal glass is composed of transparent glass panels with a white, milky intermediate layer. It is this intermediate layer that reduces direct transparency and gives the glass its opalescent appearance.
Clear glass + opal intermediate layer + clear glass
- Coloured glass
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Coloured foils create the colour
Coloured laminated glass is made of clear glass panes with one or more coloured interlayers between them. By combining interlayers, different colours and shades can be created inside the laminate.
Clear glass + coloured interlayers + clear glass
What is the difference between clear and ultra-clear glass for balustrades?
Both clear and ultra-clear glass are transparent, but regular clear glass has a more pronounced green tint because it contains more iron. Ultra-clear glass, also known as low-iron glass, has a lower iron content and therefore appears more neutral, especially along the edge of the glass and against light-coloured surfaces.
Clear glass is a good choice when you want an unobstructed view and the faint green tint does not affect the overall impression. Ultra-clear glass becomes more relevant when the glass’s tint, the view, or the colours behind the balustrade are important and you want the glass to appear as neutral as possible.
Choose clear glass when you primarily want a transparent glass balustrade. Choose ultra-clear glass when you want to reduce the green tint and achieve a more neutral look, especially where glass edges or light-coloured surfaces are clearly visible.
What is the difference between opal glass and frosted glass for balustrades?
Opal glass and frosted glass can look similar, but the terms do not always describe the same construction. Opal glass in a laminated glass balustrade consists of clear glass panes with a white or milky interlayer, while frosted glass is a broader term for glass with a matt or diffuse effect.
Opal glass is a good choice when you want to reduce direct views into the space but still allow daylight to pass through the balustrade. A frosted look, on the other hand, can be created in several ways, such as by etching or sandblasting the glass surface. Therefore, it is important to check the actual composition of the glass and not simply rely on the name.
The diffuse effect is present within the laminate
Transparent glass panels are laminated with a white or milky interlayer. The glass surface remains smooth, while the interlayer reduces direct visibility and gives the glass its light, opalescent appearance.
Frosted describes a matt or diffuse appearance
Frosted glass is a broader term and does not in itself indicate how the effect was created. For example, the glass may be etched or sandblasted, but opal glass with a milky interlayer can also be perceived as frosted.
Opal glass is suitable when the glass balustrade should give more privacy than clear glass without becoming a completely solid surface. This can be useful on balconies and patios, for example, where you want to screen against neighbours, the street or a footpath but still keep a light look.
When is grey or tinted glass suitable for a glass balustrade?
Grey or tinted glass is suitable when you want to keep visibility through the glass balustrade but give it a darker, more defined look. Grey-tinted glass is sometimes also called smoked glass. In grey laminated glass the tint is in the glass panes themselves, which are laminated with a clear interlayer.
Compared with clear glass, the grey tint subdues both the light and the surroundings behind the balustrade, but the glass is still transparent. Grey glass therefore does not give the same privacy as opal glass, which limits direct visibility much more. The choice is mainly about how much visibility you want to keep and what look the glass balustrade should have.
When is coloured glass suitable for a glass balustrade?
Coloured glass is suitable when the glass should be a clear part of the balustrade’s look, not just a transparent screen. In coloured laminated glass, the colour is created by coloured interlayers between clear glass panes, so the colour sits inside the laminate rather than on the glass surface.
The colour can be used to pick up tones from the façade, create contrast with the balustrade profiles or give the balustrade a more architectural look. How the result is perceived also depends on the colour, how transparent the glass is and the surroundings behind it. For a balustrade where both profiles and glass follow the same colour concept, there is also Color.
The colour is built up inside the laminate
One or more coloured interlayers can be combined between the glass panes to create the chosen colour and shade.
The colour affects how the glass is perceived
Coloured glass can still be transparent, but darker or stronger colours make the surroundings behind the glass less prominent and change how the light is perceived.
The same colour can look different in different places
Daylight, the background, the façade, and the colour of the profiles all affect how the colour is perceived. Therefore, evaluate coloured glass in conjunction with the rest of the balustrade and the surrounding environment.
Choose coloured glass when the colour should be an active part of the balustrade design. Don’t judge the colour sample in isolation – light, background and the balustrade profiles affect how the finished shade is perceived.
Why do glass panels for balustrades have ground and polished edges?
Glass for balustrades has ground and polished edges so that the glass edge is even, smooth and finished after cutting. This is especially important in balustrades where the edge is visible or exposed, such as with clamps, U-channels and point fixings.
Grinding removes any unevenness and small chips that may remain after cutting, while polishing gives the edge a smoother and more refined finish. Edge finishing therefore affects both the appearance of the glass and the quality of the finished glass edge before the glass is installed in the balustrade.
The visible glass edge becomes part of the balustrade design
Once the glass edge has been ground and polished, it takes on a smoother and more finished appearance. This is particularly noticeable in open balustrade structures where the edge is not covered by a post, top rail, or profile.
Edge finishing removes irregularities left by cutting
An untreated cut glass edge may have small chips and irregularities. The edge is ground and polished before the glass is installed, resulting in a smoother and more finished edge along the entire length of the glass pane.
The glass is delivered with ground and polished edges as part of the final edge finishing process. This results in a smooth glass edge that is ready for installation in the balustrade system.
What types of glass are available for glass balustrades – and in what thicknesses?
Clear, ultra-clear, grey, and opal laminated glass is available in 8.76 mm and can be manufactured in-house. Toughened laminated glass is available in 8.76 and 12.76 mm and is made to order. Coloured laminated glass is also made to order and is available in the configurations listed in the table.
Availability affects how the glass needs to be planned before ordering. Toughened glass panes are made to their final dimensions before toughening, while coloured glass is made to the chosen colour and make-up. Delivery times can therefore vary depending on glass type, dimensions and current production.
| Type of glass | Thickness | Availability |
|---|---|---|
| Clear laminated glass | 8.76 mm | In-house production |
| Clear toughened laminated glass | 8.76 / 12.76 mm | Made-to-order item |
| Ultra-clear laminated glass | 8.76 mm | In-house production |
| Ultra-clear toughened laminated glass | 8.76 / 12.76 mm | Made-to-order item |
| Grey laminated glass | 8.76 mm | In-house production |
| Grey toughened laminated glass | 8.76 / 12.76 mm | Made-to-order item |
| Opal laminated glass | 8.76 mm | In-house production |
| Opal toughened laminated glass | 8.76 / 12.76 mm | Made-to-order item |
| Coloured laminated glass | 8.76 mm | Made-to-order item |
| Coloured toughened laminated glass | 8.76 / 12.76 mm | Made-to-order item |
How do you clean and maintain the glass in a glass balustrade?
Clean the glass when dirt, pollen, salt, bird droppings, or other deposits become visible. Use water along with a mild detergent or regular window cleaner and work with a soft cloth or rubber squeegee that won’t scratch the glass surface.
Maintenance also covers the glass edges and fixings. So check from time to time that the glass has no cracks or chipped edges and that clamps, profiles and other fixings are secure. If you find damage or movement, the cause should be investigated before the balustrade is used further.
Clean the glass with soft, non-abrasive tools
Start with water and a mild detergent. Then wipe or scrape off the water so that dirt, limescale, and other deposits do not leave visible marks on the glass surface.
Avoid materials and substances that could damage the glass
Do not use steel wool, coarse scouring pads, or abrasive cleaning agents. Also, be careful with strong chemicals near the edge of the glass, where the laminate’s interlayer may be exposed, and at the same time, check for cracks or edge damage.
Make sure the glass and fixings are secure
Check that clamps, profiles and other fixings have not worked loose or been damaged. If anything needs checking or retightening, follow the installation and maintenance instructions for the balustrade system in question.
Clean and inspect the balustrade at the same time
Clean the glass as needed, and while you're at it, be sure to check the edges of the glass and fixings. Cracks, chipped edges, or loose parts should be inspected as soon as they are discovered.
How do you choose the right glass for a glass balustrade?
Start with the sizing of the balustrade system and check which glass type and thickness can be used with the glass dimensions, fixings and loads in question. The technical conditions need to be clear before you choose glass based on appearance.
You can then choose clear or ultra-clear glass for clear views, opal glass for more privacy, or grey and coloured glass when tone, light reduction and look matter more. The checklist below brings together the six most important things to check before ordering.
Check these six points
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Start with the balustrade system’s sizing
Check which glass type and thickness the balustrade system is designed for. 8.76 and 12.76 mm have different make-ups and should not be chosen just on how substantial the glass looks.
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Take into account the glass dimensions and fixings
The width and height of the glass, the distance between support points and how the pane is fixed all affect the conditions. Larger glass panels or more open balustrade systems may therefore need a different solution than smaller sections.
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Decide how important the view is
Choose clear glass when you want a transparent balustrade. Ultra-clear glass is a good choice when you also want to reduce the green tint and achieve a more neutral look, especially when the glass edges are visible and for larger glass surfaces.
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Decide how much overlooking you want to reduce
Opal glass gives a much more screened look while still letting daylight through. Grey or tinted glass, on the other hand, keeps visibility but makes the light and the surroundings behind the glass more subdued.
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Choose a colour based on the overall environment
Grey or coloured glass can give the balustrade a clearer architectural look. Judge the colour together with the façade, the balustrade profiles, the daylight and what can be seen behind the glass.
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Check the dimensions before ordering special-order glass
Toughened glass must have the correct dimensions, edges and any holes before toughening. Coloured and other specially made glass may also be made to order, so check both the dimensions and the chosen glass type before ordering.
Start with the glass type and thickness specified by the balustrade system’s sizing. Then choose clear or ultra-clear for views, opal for more privacy, and grey or coloured glass when tone and look play a bigger role.
Do you need help choosing glass for your glass balustrade?
Start from the balustrade system, the glass dimensions and how much view, privacy or colour you want. Our customer service team can help you check glass type, thickness and dimensions before you order.
What are the most common questions about glass for balustrades?
Common follow-up questions concern what can be changed after manufacture, how the tint of the glass is perceived and how different glass types can be used for views, privacy and appearance. Here are short answers to five practical questions about choosing glass.
Can the toughened glass be cut or drilled after it has been manufactured?
No. Toughened glass should not be cut, drilled or reworked in the normal way after toughening. Dimensions, edges and any holes must therefore be finished before the glass is heat-treated.
Is the green tint more noticeable in thicker clear glass?
Yes, the green tint in standard clear glass can become more noticeable at the edge of the glass and when more glass is in the line of sight. Ultra-clear glass has a lower iron content and therefore appears more neutral than standard clear glass.
Which glass gives privacy but lets daylight through?
Opal glass reduces direct visibility while letting daylight pass through. It therefore gives more privacy than clear or grey-tinted glass without the glass balustrade becoming a completely solid surface.
What is meant by grey glass, tinted glass and smoked glass?
Grey laminated glass can also be described as tinted or smoked glass. In this type of glass, the grey tint is in the glass panes themselves, while a clear interlayer bonds the glass together.
Can you combine different glass types in the same glass balustrade?
Yes. A glass balustrade can have clear glass where the view matters and grey or opal glass where you want to change the look or limit overlooking, for example. Each glass panel must also suit the sizing and fixings of the balustrade system.
