Does Tempered Glass Ever Blow Up for No Apparent Reason?
At The Shower Door Place, we sometimes get this question. In some cases, it’s from someone who bought a door from another place and had theirs blow up spontaneously. In others it’s simply someone hearing about this happening on the news or the internet. The answer to this question is, yes, it can happen, but the good news is that this is a very rare occurrence.
Let’s first talk about the glass tempering process and the nuances involved in the rare cases of spontaneous glass breakage.
Before a sheet of flat glass can be turned into a tempered glass shower door, it must first be cut to the size and shape needed for your custom shower enclosure. After the grinding and edgework is completed, it is then heated up to over 1100ºF in a large tempering oven to align the molecular structure of the glass, making it extremely tough. The glass is then rapidly cooled in a process known as quenching to retain the desired molecular structure.
When done properly the glass will be an extremely durable and safe product that will not produce dangerous shards if it ever breaks. Instead, tempered glass will shatter into millions of small pieces which will not cause serious injury.
After the glass has been tempered you could pretty much beat the face of it with a hammer as hard as you want and you’ll have a very hard time getting it to break, especially if it’s ⅜” or ½” thick like the glass we use for our shower doors. The main vulnerability of tempered glass is the edges which can be prone to chipping if struck by something hard, like metal, tile or another piece of glass. If the sheet of glass is chipped severely enough (½” - 1” in from the edge) it can disrupt the natural tension of the glass and cause it to separate into a million pieces as it’s designed to do.
In the context of tempered glass spontaneously blowing up we’ve noticed there’s a few conditions that can make it more likely although still extremely rare. The main condition being extreme heat such as in an oven, a toaster or a gas fireplace. The standard shower is well below this heat threshold. Under extreme heat glass will expand and can press against the frame that it’s contained in. If the glass was not properly fitted within that frame it can cause enough pressure to break along the comparatively weaker edges of the glass.
Another reason tempered glass may spontaneously explode is simply because it was tempered improperly. Poorly tempered glass can have imperfections in the molecular structure which creates opposing tension in the material which are essentially fighting each other until they eventually separate from themselves and shatter. Oftentimes the glass that is to blame is found in consumer products manufactured overseas where there may be fewer quality checks and oversight.
At The Shower Door Place, we use only U.S. produced glass that is fabricated and tempered locally here in Minnesota. As a business that values quality and sustainability we believe that these factors are important, given the high-quality product that our customers demand as well as the accessible nature that comes with having our glass sourced locally. In all of our years in business, installing thousands of pieces of glass, we have yet to have any of our glass spontaneously break.
We hope that this info gives you confidence in our product and our workmanship when considering us for any upcoming projects you may have.
If you would like to learn more about custom shower doors, tempered glass or anything related to it, feel free to give us a call or stop into either of our showrooms located in Roseville or Minnetonka.
