What causes toughened glass to shatter?

What causes toughened glass to shatter?

From time to time, toughened glass has been known to shatter, seemingly without reason. This phenomenon is not exclusive to shower glass, it can in fact happen to all types of toughened glass.

This is known as spontaneous glass breakage and is, in actual fact, generally triggered by one of following factors:

  • Minor damage during use of the shower or installation such as nicked or chipped edges that later develop into larger breaks through developed stress.
  • Overly tight binding or improper installation of hardware or frames adjoining the glass, which causes stresses to develop as the glass expands and contracts due to thermal changes
  • Inadequate glass thickness to resist wind load
  • Microscopic internal defects within the glass, such as nickel sulphide inclusions

While factors such as improper installation and damage during use can be avoided to some degree avoiding glass that contains nickel sulphide is somewhat more difficult. These inclusions are invisible to the naked eye and are almost impossible to completely avoid in the plate glass manufacturing process.

Is this a safety risk?

While this can be a frightening experience, there no or very minimal risk. If your glass has shattered or seemingly exploded into thousands of pieces – this means the toughening process has been done correctly and the safety element of this design has been effective.

Safety glass is manufactured this way to avoid the possibility of large shards of glass in and breakage which could lead to serious injuries. The smaller pieces mean the worst that can happen is a few small nicks and cuts.  

What is Crest Showers’ position on warranty cover?

Due to the difficulty of establishing root causes after the fact, different companies have a mixed approach on the issue. To the best of our knowledge, the majority of companies do not cover this as part of their warranty.

Our stance is simple. If there is no clear and obvious cause pointing to misuse or improper installation and the shower is within its warranty we will provide replacement glass at no cost.

In the situation where there are consequential damages as a result of the incident we would advise engaging your insurance company immediately for a full assessment and cover.  

What should I do?

First thing to do in this instance would be to take plenty of images of the bathroom – should the area need to be cleaned up you have documented the incident as it was.

Then you will need to identify the manufacturer / installer of your shower as proof of purchase will generally be required to be covered under warranty. Begin by checking any markings on the glass, contact your builder/installer if known as they will have documented contractors on your project.

Contact the customer service department of the manufacture and give as much information as you are able. It is important to allow them the time to systematically look into the incident their end- most great companies will be genuinely invested in helping you whatever the facts.  


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