What is Low Iron Glass and how does it compare to Clear Glass?   

Low iron glass, commonly referred to as extra-clear or ultra-clear glass, is a form of glass with less iron than regular ‘clear glass’. In most varieties of glass, iron is a natural substance within the base materials and is what gives glass a greenish hue when the architectural glass install is thicker or viewed from specific angles. 

Low iron glass is produced either by using raw materials that contain less iron or by eliminating iron impurities during the glass-making process. This produces glass that is clearer and more transparent, allowing more natural light to pass through the glazing design without the typical greenish hue that could be visible with conventional ‘clear glass. 

Low iron glass is the best choice for applications where colour accuracy and optical clarity are crucial. It is frequently used in architectural projects where a high level of transparency is required, such as structural glass windows, glass facades, and exhibition cases. Additionally, it’s utilised in solar panels, aquariums, photographic gear, and other circumstances where retaining an object’s true colour and clarity is necessary. 

the moorings balustrade
low iron swimming pool glazing 450 x 280

Low Iron Glass for Floors, Balustrades and Beams/Fins 

Glass Floors 

For glass floors to be able to offer the structural support required for pedestrian loads, toughened, and laminated glass is required. This multi layered glass structure provides the required strength for these types of walk on glass designs and depending on the project performance requirements insulation, they often include at least three panes of toughened glass laminated together using clear structural glass interlayers. 

You would usually opt for low iron glass for a glass floor as you would want the view from above and below to be as clear as possible. Many glass floors are used as viewing windows to a room below or a feature above such as a chandelier. The natural green tint of clear glass could affect the viewing.  Glass floors need to be atleast 3/4 layers thick to support a sufficient load of weight. If low iron glass was not used then the green tint would be highly noticable. 

Low iron glass is often the recommended option if the glass floor will be sandblasted for a slip-resistant finish. Sandblasting Low Iron Glass produces a white frosted surface as opposed to conventional glass, which reveals the green tint more clearly. 

mayfair glass floor 450 x 280
Britten street glass floor 450 x 280

Glass Balustrades 

For balcony balustrades to resist the necessary line load, at least two layers of toughened glass must be laminated together. 

If the balcony or railing is frameless, some designers may prefer to use low iron glass in their design because the green tint in conventional glass is more evident on exposed edges. 

Again you’d want to use low iron glass because glass balustrades are used when safety and viewing are both top priorities. The green tint of clear glass would affect the view out from behind a glass balustrade. Another factor to consider is that the green hue may stand out compared to the rest of the aesthetic of a home or commercial building, therefore low iron glass will be required.  

Cropley street glass balustrade 450 x 280
Edge hill glass balustrade 450 x 280

Glass Beams/Fins 

Glass beams can be used for support on horizontal glass units, and glass fins can be used for support on vertical glass units. 

In order to ensure they can handle the required load, these beams and fins—which are often the thickest glass components in the installation—are manufactured from numerous layers of toughened and laminated glass. Glass Beams and Fins will be constructed using low iron glass to ensure that the glazing it is supporting is not obstructed by any green tint. 

Solesfield rd glass lantern 921x500 1

Coloured Glass  

Low iron glass may be chosen to give a more accurate depiction of the chosen colour when utilising decorative interlayers, such as a coloured interlayer. This is particularly relevant for light, neutral, or pastel hues where even a very small green tint could distort the colour. 

Your glazier will often suggest low-iron glass if your project requires for unique back-painted glass. A cleaner canvas allows for much smoother back-painting, which results in a completed product that is the precise shade you need for your project. 

Low Iron Glass vs Clear Glass 

Clear Glass 

Contrary to popular belief, clear glass is not in fact perfectly clear.  

Standard glass – known as clear glass contains elements of iron within its raw materials. This is a result of the iron oxide that is naturally present in materials like sand or in the cask or container where the glass was heated. This integrated iron within the glass creates a very slight green tint within the body of the glass. This is not normally visible when used in typical glazing installations however, architectural or structural glass tends to use thicker glass than normal.  

As the glass gets thicker, the greenish hue produced by these higher levels of iron becomes more noticeable.  

Low Iron Glass 

Low-iron glass is produced by  lowering the iron content of the molten glass formula. This lacks the previously mentioned greenish hue and is more clear than conventional glass. In fact, reducing the iron content can boost light transparency by 5% to 6%. Low iron glass, the clearest possible building material, may reach internal light transmission levels of up to 91%. 

Low iron glass is then the preferred base glass product for glass elements that require enhanced clarity or transparency. Low iron glass is also best used for projects where thicker glass constrictions are used such as structural glazing or structurally bonded glass doors.  

While Low iron glass vs Clear glass is an ongoing debate of pros and cons for each, another discussion is European glass vs American glass. Both are manufactured if different ways and both have different situations in which you’d want to use one or the other. Read about American vs European glass here.  

When viewing is a high priority low iron glass is the best choice for glazing projects. If you value and appreciate the view from a home or commercial building then IQ Glass can specify, manufacture and install Low Iron Glass in any projects around the world.  

Contact us for any projects that require the highest quality glazing!

clear glass and low iron glass side by side