Building Weight of Window Panels

Glass Weight

• When dealing with architectural flat glass used for window panels, weight is typically measured per square foot. This makes it easy to plan for a variety of windows and quickly change plans for a larger or smaller window area. In this case, weight depends on glass thickness. Glass that is one-fourth of an inch thick weighs around 3 pounds per square foot. Glass that is only one-eighth of an inch thick weighs about a pound and a half for each square foot. Very thick glass that is one-half an inch thick can weigh as much as 6.4 pounds per square foot.

Pane Numbers

• When dealing with outer windows, the number of panes or panels is always an important consideration. The more panes in a window, the more easily the window will keep heat from passing through, which can save a significant amount of money when it comes to heating and cooling bills. But adding panes only multiplies the weight of the window. For residential houses, at least two panes are common throughout the United States. Three panes may be used for extra protection, but the structure may need to be built around the window to effectively support the panes.

Coatings

• Glazes and coatings are unique factors in window weight. When a supportive glaze (not an entire pane) is applied to a window, it can save a lot of the weight that two fully separate panes would create. However, adding a coating to a window can also can also pounds onto the original weight. That coating may threaten structural stability or at least alter the weight of a window that has already been installed. This is an issue for large commercial windows with thick coatings designed to protect and tint the glass. Many commercial windows are built on a large scale with few supports, giving small changes more impact. A simple UV protection film on a residential window should not endanger the wall around it.

Alternative Panels

• Not all window panels are made from traditional glass panes. Some panels are used as protection, such as coverings used in hurricane-prone areas. These panels are often removable, so they do not provide constant stress on the windows. Decorative panels, on the other hand, are often used as inner windows or stained glass windows in certain parts of buildings. These decorative panels can be heavier than normal glass. An 18-by-18-inch panel may weigh as much as 12 pounds. These weight calculations can be important if you are remodeling. An expansion may leave you with a window space in a wall that you decide to use decoratively, replacing the normal glass with a stained glass sheet. But if you have removed a portion of the wall in the process, the framework may start to buckle under the new weight. An architect or contractor should be able to give you more detailed advice if you share your plans for decorative windows.