Why Do Glass Patio Tables Shatter?

“It shattered just by itself“ This is a common statement you will hear when it comes to glass patio tables. According to research done by many glass experts, this is a common phenomenon. 

It is caused by a combination of a few factors. The two main factors are; harsh weather conditions and defects in the glass during manufacturing.

In this article I am going to expand on these two main reasons glass patio tables shatter, plus any other reason available. I will also give you some preventive measures that will help to avoid such occurrences in future. 

Glass patio tables can be very expensive and your value of money must be seen for many years. 

Causes of Glass Patio Tables to Shatter 

  • Defects During Manufacturing 

The problem of glass shattering can be traced back to the manufacturing process. Most glass tables are made of tempered glass. The problem develops during the tempering process. 

This is when glass is heated up to a point it is light and soft then it is cooled quickly. During this quick cooling, the outer surface cools rapidly than the inner one hence creating a center tension which makes glass strong.

Though it is a good process that makes glasses durable, during the cooling there is an impurity called nickel sulphide that is frozen at a very unstable state. 

According to chemistry, Nickel sulphide requires cooling slowly for it to be stable. Over time this nickel sulphide will try to revert to its original stable state and here is when a weak spot is created on a strong glass hence shattering.

  • Harsh Weather Conditions 

There are several ways weather can shatter your glass patio table, which are;

  1. Hail storms; this is frozen rain and they look like little rocks. When hail strikes a glass patio table it can crack it or leave a pockmark. However, this damage may not be seen by a naked eye, but they leave the table prone to shattering.
  2. Strong winds; strong winds can move patio furniture around. This makes a glass patio table vulnerable to be hit by a heavy object which in turn may shatter it.
  3. Freezing and thawing cycle; this mostly happens in areas that have severe winter seasons and there is an interchanging freezing and thawing cycle. This causes the glass to separate from the protective table frame which in turn makes it vulnerable to shattering. 

Other Causes of Glass Patio Table Shattering 

  • Low quality glass edges 

When glass is being pre-cut into smaller pieces called panels, the edges can be damaged. This might also continue during shipping or when it is being installed on the table frame. 

The poor quality of edges make the table vulnerable to shattering at any time. This is because the stress of contraction and expansion or any other environmental factor occurs around these edges. 

  • Expansion and contraction of the table frame 

This occurs when there are no gaskets or setting blocks between the metallic frame and the glass. The gasket acts as a cushion preventing direct glass to metal contact. If there is a direct glass to metal contact, a stress is produced on the glass which may lead it to shattering.

  • Thermal stress 

This is stress created on glass due to positive temperature changes, that is, the temperature at the center of the glass is higher than at the edges. This leads to tensile stress on the glass edges. When the stress exceeds the strength of glass edges shattering may occur. 

Tips on Preventing your Glass Patio Table from Shattering 

  • Buy glass patio tables from qualified manufacturers 

Buy your glass patio table from a manufacturer who has done a process called heat soaking on the glass. 

Heat soaking is the process of removing the nickel sulphide from the glass, which is the main agent of glass shattering. 

During heat soaking, glasses that are contaminated by nickel sulphide are removed before they reach the market. 

  • Store when not in use 

During months with bad weather conditions you are advised to keep glass patio tables indoors. This is because among all other patio furniture glass tables are the ones in high risk of shattering. Make sure you clean the glass table before storage and cover it with a patio furniture cover to avoid dust and dirt. 

  • Close down open umbrellas on your glass patio table  

Open umbrellas trap a lot of objects such as strong winds. This is because a gust of wind will carry the table with an open umbrella more easily than the one with a closed umbrella. 

Other Tips that May Reduce the Risk of Glass Patio Table Shattering 

  1. While assembling the glass table, make sure you lay the glass on a soft place like on a piece of cloth, blanket or on the carton box. 
  2. Always ask for help any time you are lifting the table or moving the table. This is because moving this glass table on your own can lead to unexpected accidents. 
  3. Avoid placing extremely hot or very cold substances directly on the glass table. This may lead to a big temperature difference that can make the glass patio table shatter. 
  4. Always avoid using the glass table when any part of it is missing or broken. For example, do not use the table when one of its legs is broken or shaking. 
  5. Avoid standing on the table or even sitting on it. If you have small children make sure they do not play on the table. 
  6. Avoid dragging rough and heavy substances on the glass table 
  7. Avoid hitting the table with sharp objects like a knife. For example, do not use the glass table as a chopping surface. 
  8. Clean the glass patio table regularly to avoid drift on the table.
  9. Always cover the table when it is not in use. This will protect it from harsh weather conditions and any other accident. 


A glass patio table shattering is a common phenomenon. But getting high-quality glass that has gone through the process of heat soaking is the first consideration. Follow all other tips that are given above and you will never see your glass patio table shattering for many years.