Glass Types

Low-E

A highly energy efficient glass that reflects heat producing long-wave and ultraviolet light. In the winter, heat (long-wave radiation) is reflected back into the room. In the summer, the sun’s light is filtered which reduces the solar gain. Low-E glass is made by applying a special coating to the glass.

Tempered

Like tempered steel, the strength of glass can be increased by rapid cooling in the manufacturing process. By quickly cooling glass from 1200 degrees to 400-600 degrees, it will become 4 times stronger than normal glass. Often referred to as safety glass, it is highly resistant to breakage. When it is broken, this glass will break into small, almost square shapes, not dangerous shards. Because of the way it breaks, tempered glass will remain in the window instead of flying about and is much easier to clean up.

Tempered glass is used anywhere potential impacts with objects is a concern. Many local building codes will require the use of tempered glass if a window sill is within 12 to 18 inches of the floor.

Tinted

Various colors can be added to the glass formula during manufacturing. The tinting materials help filter sunlight as it passes through. This reduces the amount of solar, or heat gain. Tinted glass is typically used in large southern exposures where tremendous amounts of heat gain can be anticipated.

Reflective

A metallic coating applied to one side of the glass during the manufacturing process both reflects sunlight and limits the ability to see through the glass from the outside. Reflective glass is typically used on large southern exposures or where privacy is a consideration.

Heat Strengthened

Not as strong as tempered glass, heat strengthened glass is manufactured using a lower temperature and whose strength is 2 times greater than standard glass. It’s break pattern is also similar to tempered glass in that when broken, will break in a square type pattern and remain in the window frame. Not considered as safety glass, and cannot be used in place of it to be in compliance with building codes.

Obscure

At least one side of the glass is finished in one of a various number of textures that impede clarity. Often used in bathroom windows, shower doors, or anywhere you want to allow light to enter but not prying eyes, this glass can be tinted and tempered (required for shower doors).

Wire

Actually 2 sheets of glass sandwiching a woven metal grid. Typically limited to commercial applications, primarily in the shipping and receiving or warehousing areas of a business, this glass is very difficult to break. It is also unattractive to look through.

Laminated

Actually 2 sheets of tempered or heat strengthened glass, sandwiching continuous sheet of plastic. The glass adheres to the plastic but since the plastic is clear, is invisible. Since this glass adheres to the plastic, if it is broken, will not fall from the frame. Laminated glass provides many of the characteristics of wire glass but is much more visually appealing. Use of laminated glass may be required by local building codes, especially for large or sloping windows, windows above a certain height, or when the window is beyond a certain thickness.