TECHNICAL ADVICE

What is Low Iron Glass and when is it needed?

What is Low Iron Glass?

Low iron glass is glass that is specially manufactured to have a lower iron oxide content. Standard ‘clear’ glass is not completely clear, it has a slight green tint due to the presence of iron oxide.

The tint is not usually noticeable, however it can become noticeable in thicker panes of glass, when multiple panes are layered together or on an exposed glass edge. Projects that require these kinds of glazing units would benefit from low iron glass to avoid discoloration.

When glass is manufactured there are a variety of materials and impurities that are present. The natural presence of iron oxide in glass comes from elements such as sand or from the container in which the glass was melted.

Low iron glass is also useful when two different glass specifications are being used in the same installation. If a thicker glass pane is next to a thinner one there will be a slight difference in colour.

A solution for this issue is to use low iron glass for the thicker glass elements but not the thinner ones, giving them the same level of clarity for a consistent look.

Just like float glass, low iron glass can be toughened, laminated and designed with different finishes such as sandblasting.

Low Iron Glass for glass floors

Glass floors need thick, toughened and laminated glass to be able to provide the structural support needed to allow people to walk on it. This means they tend to have at least three pieces of toughened glass laminated together, possibly more depending on the desired insulation.

Sieger’s Thermally Broken Floorlight is engineered for heavy pedestrian traffic, using three pieces of toughened glass laminated together for the external pane and two for the internal pane.

If the glass is going to be sandblasted for a slip-resistant finish, then low iron may be the better choice. When normal glass is sandblasted the green tint becomes more obvious but when Low Iron Glass is sandblasted it becomes a white frosted surface.

There are other ways to make a glass floorlight slip-resistant, such as ceramic frit or specialist anti-slip glass if you do not want low iron glass or a green tint.

Low Iron Glass for balustrades

Balustrades used in balcony settings are made from at least two layers of toughened glass laminated together to be able to withstand the required line load.

Although this may not be as thick as other pieces of structural glass such as glass walls, when using units such as The Sieger Balustrade System the edges are visible.

The green tint in standard glass is more noticeable on exposed edges, if the balustrade or balcony is frameless some may want to opt for low iron glass in their design.