Where vinyl shower curtains can be quite unsightly and missions to keep clean, glass shower doors are their luxurious and sophisticated counterparts. A bathroom can be truly transformed from drab to fab when a glass shower door is installed.
Despite their glamour, these doors can also be quite hazardous as not only can slipping in the shower become more dangerous if you hit your head on the door, the doors themselves are known to explode on occasion.
Glass shower doors can explode or shatter. The cause of these seemingly spontaneous occurrences is unknown, but thermal expansion, nicks in the glass edge, improper installation, and nickel sulfide inclusions are all suspected. Glass shower doors are made from tempered glass, so serious injury is unlikely.
Glass Shower Doors Do Explode
“I bled substantially from a wound on my right foot and had to walk on glass to get out“. These are the words of a victim of a spontaneous glass door explosion that occurred while he showered (NBC News).
Late last year, a San Diego resident was simply enjoying his time watching television in his living room when a loud crash came from the bathroom. Luckily, he was spared from injuries as he was not in the bathroom when it occurred.

Despite the numerous procedures put in place during construction, glass shower doors can shatter at any time, often without warning. The huge mess aside, this can be a serious danger to any person or pet in the vicinity of the shower.
In the early 2010s, the US reported over 2000 instances of people being rushed to the emergency room due to exploding shower doors. More recent data suggests that the number has doubled over the past 5 or so years.
Safety Glass Is Still Glass
Your shower door is not likely to be made the same way as your drinking glasses. Glass shower doors are made of stronger and thicker safety glass.
This does not, however, make them indestructible. They are still made of glass, which can break and shatter. The difference is that they are manufactured in such a way that they are less likely to break in response to harder impacts, such as if you were to bang your arm against the glass accidentally.
Furthermore, if the glass does break, it won’t shatter into large and dangerous shards that can easily slice through skin. Instead, it is designed to shatter into smaller ‘nuggets’ of glass that are not very sharp, to limit their dangerous effect.
Occurrence is Rare
While reading this, you may start to get a bit anxious if you have a glass shower door in your home, or might be reconsidering installing one if it had been on your mind.
Luckily, an exploding shower door is really not as common as the stats provided above made you believe.
The numbers seem high when taken out of context. The report of 2000 injuries spans a few years and the US has millions of citizens.
Statistics have revealed that the chance of your glass shower door exploding is only 1 in 7 500. This means that there really is a slim chance of this happening. You probably won’t even know someone that it has happened to.
It is far more likely that you will have a gas leak in your home, or experience a fire as a result of your dryer. The US alone has reported nearly 20 000 fires related to dryers each year.
Reasons Why Glass Shower Doors Explode
It seems to be a bit of a mystery why glass shower doors explode for no apparent reason. But, while no one really knows for sure, there are some educated guesses we can make of the likely causes of the phenomenon.
Thermal Expansion
Thermal expansion is the tendency of materials to change their shape, volume, or density in response to changes in temperature. So, when the temperature rises, an object may expand; when the temperature drops again, the object contracts.
Extreme temperature changes can be a reason that your glass shower door explodes unexpectedly. The shift from hot to cold can cause the glass to expand and contract, ultimately shattering.

However, the temperature shifts that occur naturally as day turns to night is not likely to cause your shower door to explode. It would more be in response to the heat from a shower, and even then, it would have to be accompanied by another stressor in order to shatter.
Nicks in the Edges/Drill Holes
Experts have found that one of the top reasons for an exploding glass shower door is because of damage to the edges of the glass door. Small nicks in the perimeter of the door act as weak points and any subsequent impact to this point may be enough to shatter the door.
Drill holes can also act as weak spots, making the entire door unstable and susceptible to exploding. This may also make shattering more likely in frameless shower doors.
It is advisable to properly inspect your shower door at least once a year for any small cracks or nicks that have the potential to spread.
Improper Installation
Sometimes choosing to go the cheaper route and DIYing projects may come back to haunt you. Installing a glass shower door is something that should be done by a qualified professional. It’s not very difficult, but if you don’t know what you’re doing, you can cause real problems for yourself.
Inadequate installation can be the make or break between having a stable and secure shower door, or the reason for a glass mess.
Loose screws or insecure hinges could be the culprits of the disaster, as the shower door can simply slip off the hinges as you open or close it. Having broken parts in your shower door, such as torn rubber seals, can also contribute to the likelihood of experiencing the unwanted explosion.
Nickel Sulfide Inclusion
Another possible cause for exploding glass shower doors is due to the possible inclusion of nickel sulfide in the glass that could essentially damage it.

Sometimes, during the manufacturing process, microscopic pebbles, known as nickel sulfide inclusions, can get trapped within the glass itself.
When the shower door comes into contact with heat, the glass and nickel sulfide inclusions expand and contract with the heat in the bathroom. Nickel sulfide is more sensitive to the thermal input, and the more excessive response has the ability to weaken the glass over time.
For more details on the causes, check out Why Shower Doors Suddenly Break (Explode).
Is It More Likely to Occur When Shower’s in Use?
A lot of the time, people report exploding shower doors while they were using the shower. However, this does not mean that it won’t explode when you are not using it.
Many people have experienced hearing a loud crash coming from their bathrooms, while they were in another room.
The tendency for the shower door to explode while someone is using it may be due to it already being unstable (due to one of the factors mentioned above). A small knock from your elbow while you reach for your shampoo or that one last thermal expansion cycle could cause it to shatter while you are in the shower.
Serious Injury Is Unlikely
Despite the shock and possible nicks you could get from handling the glass, the risk of serious injury resulting from an explosion is quite unlikely.
Glass shower doors are made from tempered glass, which does not cut as easily as non-tempered glass. So, you should be able to sweep it away or pick it up with minimal harm to your hands.
If the glass doors explode, the fact that it shatters into tiny pieces means that you are less likely to suffer from blunt-force trauma that could occur from a falling sheet of heavy glass.
If you are in the shower when it happens, you may get a few small nicks, and the glass is unlikely to get into your eyes as the pieces won’t be small enough.
Sources
https://www.glassone.com.au/glass-repair/information/what-causes-glass-shower-screens-to-explode
https://info.glass.com/what-causes-glass-shower-doors-to-explode/