The appalling injuries that wired glass can inflict has led to its banning in the United States.
Despite its traditional status as a form of “safety” glass due to its internally reinforced structure, wired glass is increasingly being viewed as both obsolete and hazardous due to the serious injuries it can inflict upon impact, as well as the development of viable alternatives.
As implied by its name, wired glass consists of glass containing a welded wire mesh at its centre. While the impact resistance of wired glass is little different from that of standard glass, the wire mesh serves to hold the broken pieces together in the case of smashing or rupture.
The material was originally used in situations where glass at elevated heights posed a potential hazard to by-passers below – such as skylights and elevators. Its role in these contexts has since been largely superseded by laminated glass, which is a considered a preferable option.
Wired glass continued to be employed, however, as a fire-rated glass, because the ability of the wire mesh to keep broken shards together enables the glass to hinder the spread of fire in buildings. Laminated glass is incapable of performing this role because the plastic laminate itself is flammable and can actually worsen fires.
For these reasons, wired glass was long considered the only truly practicable form of fire-rated glass, and is still extensively employed in buildings around the world where fire safety is a vital consideration. This is particularly the case for the fire doors of public facilities, such as schools, hospitals and parking garages.
Wired glass is no longer the only viable form of fire-rated glass, however, following the development of fired-rated glass ceramics that provide both fire protection and impact safety.
Wired glass also suffers from a severe shortcoming in the form of its heightened susceptibility to breaking upon impact. While the wire mesh serves to keep the glass fragments in place after smashing, it also serves as a structural discontinuity which makes the glazing weaker than plain glass of commensurate thickness.
A barrage of evidence has since emerged indicating that this weakness makes wired glass a serious hazard to human safety in the case of impact, due to the severe injuries the wiring in tandem with the fractured glass can cause.
A landmark report published by Canada’s Ontario School Board Insurance Exchange in 2000 reviewed 107 claims against school boards over glass injuries across a 13-year period. The report said that “wired glass can cause horrible injuries,” and is “extremely hazardous in impact situations.”
Major claims continue to be launched against school boards in North America for appalling injuries incurred as a result of accidents involving wired glass.
In 2010, Ravelle Sidial filed a $1 million suit against the Toronto District School Board, alleging that he suffered severe injuries when his arm passed through a wired glass door after he ran through a hallway at Lester B. Pearson Collegiate Institute. These injuries included “severed tendons to his right hand and a severed artery,” which required surgery and extensive painful physiotherapy.
In January 2013, a similar case was filed by Sergio Jiminez in New Jersey against the Board of Education Morris Hills Regional District. Jiminez claims to have suffered permanent injuries when his arm passed through a wired glass window as he was departing from schooling in February 2011.
As a result of these developments, the US’ 2006 International Building Code (IBC) effectively banned the installation of wired glass from all human traffic areas. Calls are now mounting in Canada for the implementation of a prohibition.
In Australia, the issue remains unaddressed, with wired glass still widely available as a safety glass, which is defined as a glass that does not pose a safety hazard when broken.