Double-pane windows leak due to seal failure or glass damage. According to the International Association of Certified Home Inspectors, chronically leaky windows invite unsightly mold growth and do not retain heat as efficiently and those with intact seals. About expert Lee Wallender explains that leaking double-pane windows do not require total replacement unless the faulty seal is beyond repair.
There are four strategies for fixing leaky double-pane windows. When a window leaks due to glass damage, one effective solution is to hire a glazier to perform in situ replacement of one or both panes. This approach saves time and money because it leaves the window frame intact.
Windows with punctured seals but no glass damage only require seal repair. The most common procedure involves installing a valve on the seal to extract moisture and prevent more of it from seeping between the panes. Once the window is dry, many repair experts fill the space with an inert gas such as argon.
Lee Wallender writes that the third option is to do nothing. This solution only works in moderate climates where a single broken window seal does not cause a significant increase in climate control costs. In climates with severe winters or scorching summers, this tactic is not a viable long-term solution.
The fourth strategy for dealing with leaky double-pane windows is to replace the entire window, including the frame, seal and both panes of glass. This is an invasive procedure that often takes several days. It is also the most expensive approach.