A common fixture in older industrial buildings and lifts, wire mesh glass (sometimes known as Georgian Wired Glass) is one of the oldest safety glass technologies ever created and was so effective at resisting fires that it would take decades for other technologies to catch up.
However, even in countries where Georgian glass has not been banned entirely, the difficulties it causes to window glass repair, the tendency it has to accentuate injuries and the disconnect between what it is good at and what it looks like it is good at has caused it to lose favour in recent years.
This has gotten to the point that in 2006, wired glass was banned for use according to the United States International Building Code, as well as debates around the world about its continued use as a safety glass.
Initially patented in 1892 by Frank Shuman, wire mesh glass consists of a sheet of glass with a thin metal wire embedded in the middle, similar to the rebar used in reinforced concrete.
Initially, it was believed to work the same way, but one very early benefit was found in the world of fire resistance.
Unlike other types of glass at the time, wire mesh glass keeps the glass from falling out of the frame even if it cracks due to the effects of thermal stress, making it more heat resistant than laminated safety glass, initially invented in 1903.
As a result, wire mesh glass was used in industrial and institutional fire doors, as it allowed for a relatively clear viewing panel without interfering with the door’s ability to block heat and smoke.
However, it turned out that, unlike reinforced concrete, wire mesh glass was actually weaker than unwired glass due to the wire itself creating potential stress points that can early be broken.
What made this worse is that the wire itself makes any shattered glass more irregular, which translates to sharper, more dangerous edges.
Because of this, wire mesh glass’ use in schools has reduced significantly, replaced with safer alternatives using better toughening and lamination methods.