On average, windows should be replaced every 20 years. However, there are several factors to consider to determine the best time to replace your windows.
The first is the type of window to replace. The second is deciding to replace your windows at the point of energy efficiency maximization or later. The following is a chart to help you determine the best time to replace your windows in relation to energy efficiency and average window lifespan.
It helps to understand how glass changes over time when considering when to replace your windows. Here’s a little known secret about windows; the glass in your window does not degrade, the window frame and seals degrade.
Windows could theoretically last forever.
Glass, if left at room temperature doesn’t degrade. Glass is a solid that is highly resilient and stable. According to Lori Baker of MIT School of Engineering “glass is made by pouring molten glass onto a pool of molten tin, resulting in very flat, clear, uniform sheets. This ”float glass” method was pioneered in the 1950s and is very different from older methods of fabricating sheet glass, which involved blowing large bubbles of molten glass, cutting them off the blow pipe, splitting them open, flattening them all while hot and soft, and then cutting into panes after they had cooled. The resulting bull’s eye marks, warps, and lines are remnants of the manufacturing process—and have remained stable for, in some cases, hundreds of years.”
There are however, environmental factors that can degrade glass.
Stress and abrasion
Water can damage glass by putting force on a crack, flaw or weak point on the glass. For example, if there is a high wind storm the rain water can put pressure on your windows, especially if the rain has small particles in or is sleet or hail. A microscopic crack or flaw in the window can suddenly appear as a new crack after a heavy rain storm because a pre-existing crack was made larger.
Another example is if an object hits the window previously and a small dent or crack was created without you being aware. The high wind storm can aggravate that window flaw and break the glass.
Take extreme caution when you are pressure treating and cleaning the outside of your house that you do not put too much pressure on the frame of your windows as this can shorten the life span of your windows. Pressure treating your window frames can break the seal on the window frame, degrading your insulation and increasing inefficient window leaks. This scenario can be especially damaging if you have double pained insulated windows. If the seal is broken or cracked during pressure treatment the gas in between the window layers will leak which causes cloudy or foggy windows.
Chemicals and Temperature
Some chemical solutions can degrade glass but this does not include any of the standard cleaning solutions that would typically be applied to your windows. Extreme temperature changes can inflict damage to glass as well but once again, not the typical weather that windows endure.
If you have sun facing windows that endure the majority of daily sun exposure installing window awnings will help preserve the life of your windows. Sun damage over time will degrade your window insulation quicker than the average life expectancy for that type of window.
If you are experiencing window degradation, most likely it is caused from the seal and frame of the window rather that the actual glass itself. The glass can last the lifetime of the house.
Sometimes replacing the entire window would be the same cost as replacing the frame and seals. We will give you the best quote for either window replacement or window repair and let you know what the best quality for the most savings will be.