Glass in balustrades acts not only as an aesthetical element but must be able to fulfil the technical requirements that make it safe. These include point loads , uniformly distributed loads and containment. Most standard systems utilize primarily 10mm toughened glass. This thickness is enough to comply with the required loads.
Types , colours and options
With 10mm thickness of glass there are some standard tinted glass options. These are tints which are part of the glass and are made so in the glass manufacturing process. With this type of tinted glass , the thickness of the glass determines the darkness or lightness of the tint. This means the 6mm bronze tint will be lighter than 8 , or 10mm.
The tinted glasses that are available in 10mm are: Green , Bronze , Grey and also in a blue tint.
10mm glass is also available in an opaque finish. With monolithic 10mm glass this is available either in an “acid etch” sanitized type , or in clear glass that is sandblasted to make it opaque. The sandblasted option gives the glass a rough surface and a kind of white finish.
The sanitized option is smoother but it should be noted that when the glass is wet the sanitized becomes almost clear.
With laminated glass it is possible to have a white interlayer to create this opaqueness.
Laminated glass can also be used for balcony. Normally glass that is both laminated and also toughened is being used on both sides. Laminated glass is glass made up of several parts , glass with a plastic interlayer and another glass.
The minimum thickness of a laminated glass type that you can use is a 9.5mm glass which is made up of two toughened 4mm panes and a 1.5mm interlayer of plastic in between these two panels.
The main difference between laminated glass and toughened glass is that laminated glass should remain in place even when it’s broken whereas toughened glass is a lot stronger and will take a lot more force to break but once it breaks it shatters into small little pieces and will no longer be there in the opening once it has broken.
Glass Balustrade Types
there are many versions of glass balustrades that are available in the market these days.
They should be broken down into two main categories:
• Glass balustrades that are reliant on posts
• Glass balustrades that are reliant Structural Glass
Glass balustrades that are reliant on posts
The first type would be the posted type which means they rely on the vertical posts for their strength.
This type of system can have variations in types of post , frequency of posts , how the glass is connected to the post or if there’s a handrail or if there isn’t a handrail.
This is more the traditional system and will usually have post fixed at regular intervals of appx 1.0m. Most posted systems will have and use corner posts. Glass is usually fixed via claps or lugs that are fixed to the post and hold the panels.
Glass balustrades that are reliant Structural Glass
The other type of glass system would be a structural glass balustrade. It is called structural because the glass acts at the structure and not just a panel that in fills the gap. This type would rely on the strength of the glass for the loading. The glass being strong enough to take any load applied onto it.
The structural glass balustrade also varies to some degree but always cantilevering the glass (By cantilevering is meant that the glass is in embedded into a type of “U” channel or some type of clamping system that holds the glass panel at the bottom of it while the load is applied to the top of the glass) Invariably a structural glass system will require thick panels of glass , usually with a minimum of 15mm and toughened. The glass itself acts as the barrier and is the balustrade both the infill panel and the load bearing element (structure) , or the resister to the loads applied.
On top of a structural glass balustrade you would normally have a handrail. That handrail per British standard must be able to support the load if one of the glass panels breaks and there’s a gap between two glasses that handrail must be strong enough to take the required load across the empty area that is missing the panel.
Structural glass system can now be made without any handrail , as long as the correct thickness of glass is used and that the glass must be laminated. These are also known as fully frameless systems.