float glass st catherines college

Float glass: from the late 1950s

Float glass (also known as modern glass) is an option for both our Thin Double Glazing and our MONO single-glazing solutions.

Float glass is a contemporary style of glass suitable for use in both modern and period buildings. It can also be toughened (tempered) or laminated for safety and security purposes. Float glass is suitable to use with our Thin Double Glazing and our MONO Laminate single-glazing system.

Thickness: 3mm or 4mm, depending on the specification.

How do we use float glass?

In our Thin Double Glazing, float glass is always used for the inner pane, and it features a low-emissivity (or ‘low-e’) coating. The outer pane can then be any type of glass,  including float glass.

Our Mono Laminate system also has an inner pane of float glass, coated with an acoustic and thermal insulating film, and then an outer pane. That outer pane could be float glass or a period glass style.


What period does float glass suit?

Float glass is most commonly seen in buildings from the 1960s onwards, so it’s often specified when we supply glazing systems for more modern properties. However, there are plenty of reasons why you might want to use float glass in considerably older properties, too, either as a single-glazed pane or as the standard inner pane in our Thin Double Glazing. We’re here to advise you on this.


How is float glass made?

Float glass is made by floating molten glass over a bed of liquid tin. The result is truly flat and mirror-like, and of a fine quality without waves, bubbles or distortions. Depending on how you feel, that could be an advantage or a disadvantage (you might be looking for more character for older period properties, in which case we’d suggest hand-drawn, machine-drawn or cylinder glass).


What about safety features?

For the glazing of windows and doors below 800mm, laminated or toughened glass should be considered. Thanks to modern production techniques, float glass can easily be turned into safety glass, of which there are 2 main types:

  • toughened (or tempered) float glass – 4mm thick, unless requested at 3mm for a large project
  • laminated safety glass – 6mm thick.

We’ll be happy to provide guidance as to the correct choice of safety glass.