Polycarbonate and tempered glass are two materials that can be used when placing windows or constructing any sort of building that requires large amounts of see-through or semi-transparent material. They have similar properties, as well as different advantages and disadvantages.
Advantages of Tempered Glass
Many people no longer advocate the use of tempered glass; however, it has a number of advantages over polycarbonate. For visual purposes, tempered glass is far superior to polycarbonate in clarity. You can see through it with less fog. It also is less susceptible to damage from heat. In addition, when one part of tempered glass shatters, the entire pane shatters, which allows easy replacement of panes. Finally, tempered glass is heavier than polycarbonate, which can be useful under certain design specifications.
Disadvantages of Tempered Glass
Tempered glass has a number of disadvantages as well. It can be very expensive. Due to its weight, it requires a significantly stronger frame to support it. In roofing applications, if a crack appears, the entire pane cracks, which is generally not desirable. It also doesn't diffuse sunlight, which can lead to hot spots when used in an overhead position.
Advantages of Polycarbonate
There has been an increased use of polycarbonate in recent years because it is cheap, light and nearly indestructible. When installed, it easily makes a watertight seal. It also diffuses sunlight, which leads to few hot spots.
Disadvantages of Polycarbonate
Polycarbonate has only two major disadvantages, both of which are design considerations. The first is that it has less visual clarity than tempered glass. The second is that it is lighter, and if bulk is desired, it may not be heavy enough for those applications.