Plate glass was the industry standard until around 1960 when float glass became the new norm. Float glass is less expensive to make, requires much less sanding than plate glass, and allows for a smoother surface with fewer irregularities.
History of Plate Glass
Plate glass is no longer made in the United States. However, it can still be found in some older homes and is highly sought after by homeowners looking to preserve a bit of history.
The roots of plate glass date back to 17th-century France. Plate glass later evolved into the Bicheroux process in which the glass was cast and then rolled into long, thin sheets that were heated and cooled to increase durability. The glass was then cut to size, ground, and polished to produce a smooth surface.
In 1952, Sir Alastair Pilkington invented the float process of making glass. Float glass is made by creating a surface in which liquid glass is poured over a molten tin, causing the lighter glass to “float” and create a level surface before cooling.
This method of making glass has been the standard for the past half century.
Advantages of Float Glass Over Plate Glass
Float glass has a few advantages over plate glass, such as:
More affordable—Plate glass is only manufactured in a handful of locations around the world and is imported to the U.S. Plate glass is more expensive to make, and that combined with importing costs means that plate glass comes at a premium price for American homeowners.
Better insulation—Plate glass offers poor insulation which leads to higher energy bills, an indirect expense to their already high cost.
Higher quality—Plate glass cannot achieve the quality standard of float glass, which has a smoother surface and fewer imperfections.