Are Frameless Shower Doors Safe?

Frameless glass shower doors are constructed of tempered glass, or safety glass, which is less susceptible to breaks opposed to laminated and annealed glass. The likelihood of breaks occurring are slim but the possibility is always there. 

Tempered glass for frameless showers are fabricated in 1/2 inch and 3/8 inch thicknesses. This glass is specially treated to reduce the risk of injury if it should break.

Tempered glass is about four times stronger than laminated or annealed glass with a minimum surface compression at 10,000 pounds-per-square inch. If annealed glass were to break, it forms shards and jagged pieces that can easily cut or cause injury. In the unlikely event that tempered glass breaks, it forms small pieces that reduce the risk of injury. Tempered glass breaks like this because of the way it is manufactured by heating and then rapidly cooling the glass.

Safety glass can also be manufactured by heating annealed glass to around 680 degrees Celsius. The glass is placed on a roller table, rolled through the furnace, and then rapidly cooled with forced air jets (process known as quenching).

Tempered glass can also be manufactured through a chemical process by submerging the glass in a bath of potassium salt. This causes an exchange of sodium atoms with potassium atoms which are much larger and provide more strength within the glass. 

Any modification to glass must be made before the glass is heat strengthened or chemically strengthened. If any holes are drilled or any cuts made to the glass, the newly tempered glass will break.

Although safety glass is much stronger and more resistant to breakage, it is still susceptible to breaks. Tempered glass has an overall balance of stresses among the glass itself but if a concentrated blow with a hard object were to occur, tempered glass can eventually shatter. Tempered glass is most known to break if dropped on its' edge where the glass is much weaker at around 9,700 pounds-per-square inch. 

Tempered glass does not alter the appearance of clear, tinted, or etched glass patterns.

The thermal process used to treat the glass makes it heat-resistant for many applications besides frameless shower doors. Tempered glass is useful in applications where it will be exposed to heat, such as car windshields and computer screens. Other uses of tempered glass include residential construction projects, home appliances and commercial applications.