Have you been hearing more about glass exploding…“spontaneously”? It can happen in the blink of an eye, with small pieces of glass raining down everywhere. And it’s not just exploding glass shower doors it happens to.
So, how can this happen to tempered glass when some installers even take blows with a hammer to it demonstrating how tough it is?
What is tempered glass: ordinary, or annealed, glass is cut to size with holes drilled into it and other desired fabrication completed first. It is then examined for imperfections, the cut edges are sanded smooth and the glass is completely washed. Following this, the glass is tempered by heating it to approximately 620°C (1,148°F) and then quickly cooled, making it 4 to 5 times stronger. By tempering the glass it is not only stronger but is designed to break into small pieces as opposed to large shards like plate glass would. It must not be cut, ground, or drilled after it is tempered.
Where You Might Find Tempered Glass in Your Home: shower doors, deck railings, glass vessel sinks, table tops, oven doors, TV stands, desk tops, fireplace doors, basketball backboards, etc. Check with the manufacturer of your product to see what type of glass has been used in your application and follow the manufacturers’ specifications for installation and use.
Causes for Failure: nickel sulphide (NiS) inclusions in the glass material itself, damaged edges that are nicked or chipped during handling / installation, or edges that are ground after the glass was tempered. Sometimes the glass is simply too thin for its size or it is too tight within its frame to allow for expansion / stress. Impact and extreme temperature changes can also cause the glass to break. While glass failure may occur after it is manufactured, installed or stressed…it may occur many years later, making the predictability of its demise very difficult.
Safety Precautions / Remedies To Consider: don’t subject the glass to rapid temperature changes, don’t shake, rattle or slam the glass, avoid impacting it with hard or sharp objects, and protect the edges of the glass. Consider having a safety film professionally installed over the glass (if suitable in your application) to reduce the amount of broken glass flying off everywhere. Other types of glass, such as laminated heat-strengthened glass, may be an alternative to consider in your particular application also.
If you’re concerned about exploding glass shower doors, protect yourself…get it inspected!