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Over the last few years, there have been various accounts, both internationally and locally of shower doors exploding without provocation or reason. A quick google search leads you to hundreds of reports and videos of this happening. These accounts all have a few things in common:

  • The shower door exploding into millions of pieces without any provocation
  • The shower frame stays mostly intact
  • A very loud sound

Although this mysterious shower explosion is enough to freak out anyone with a shower in their house. This phenomenon can be easily explained and thus, even more easily, avoided.

Firstly let’s look at how the tempered glass is made. According to the Scientific American (2001), tempered glass is made by cutting it into the desired shape and size. It is then heat treated in a tempering oven at a temperature of 600° – 620° Celsius. After the heat treatment, the surface of the glass is blasted with high pressured air in order to rapidly cool it down. This is called quenching. This means that the outer surface of the glass is cooled more rapidly than the center. This causes tension as the center of the glass tries to pull away from the outer edges as these go into compression. This is what makes tempered glass so strong.

In general tempered glass has a surface tension of 10 000 psi and only breaks at a tension of 24 000 psi (Scientific American, 2001). This means that if the glass in your shower door or panel is put under too much tension, it shatters at its weakest point. You are then left with a shower door explosion and quite a bit of clean up. Mark Meshulam, states that although the shower doors seem to spontaneously explode, there is always an underlying cause or reason.


Reasons shower doors explode:



A tiny crack or chip can happen when the shower panel or door is damaged on its outer edges. This kind of damage might not cause the shower to shatter immediately, but over time the tension increases on this weak point and causes the explosion.

Uneven Surfaces

According to Andrew Endean (2019) our Shower Specialist, another reason for shower doors exploding is that the surface the shower is installed on is not level or even. This imbalance in tension creates unequal stress on the glass panel which leads to an explosion when the surface tension increases. For safety reasons the surface your shower is installed on should be level.

Incorrect installation

Another reason for shower doors exploding is when the rubber gaskets that need to be installed between the metal components and the glass panels are either left out or are not correctly fitted. This causes metal components to damage the edges of the glass which can cause a weak point which, as we know by now, will not be able to deal with the tension.

If tempered glass is forced into place, it most likely will eventually shatter. If tempered glass has a weak point due to damage it could be shattered by tremors or any other intense vibration such as that caused by loud noise or constant traffic.

Temperature Change

The temperature change caused by having a hot shower on a cold day is not enough to cause shower doors to explode on their own. However, if the shower has a weak point due to damage, over time the expansion and contraction of the glass due to temperature changes can worsen the pre-existing damage and increase tension on the weak point causing it to explode.

Poor Quality

Another common reason for shower door exploding are due to sliding doors coming off their tracks, exposing the glass on impact. Prima Bella has employed the claw rail track to curb this problem. The claw rail track prevents sliding door wheels from accidentally derailing.


There are many ways to avoid the above scenarios, the easiest of these being that the shower should be installed by an authorised technician. The technicians are well versed in installing your shower properly. They will thoroughly assess the installation area before proceeding and ensure that all components are fitted correctly.

Other ways to avoid this are to make sure that your shower is working optimally and cleaned regularly. To avoid unnecessary pressure on the glass, do not use the handles or knobs as a means to support body weight.

If you are concerned that your shower might be at risk of exploding, you can book a shower evaluation with Prima Bella. This means that our technical team will come out to your home and inspect your shower for any irregularities.

There are no accurate times associated with showers shattering. It could be immediately upon faulty installation, or it could be a decade later, when the shower panel is unable to sustain the uneven stress it is put under due to the reasons above.

To book your shower evaluation, please send an email to or call us on 0860 228 476 or 0860 746 937. Also take a look at our informal strength test we performed on our own shower doors.