Q: why are my new windows sweating on the outside? I just bought these beautiful replacement windows and they look so nice. But now they’re leaking water! All over my house, all day long. What can I do to stop this mess?
A: The first thing you should know is that it is not your fault at all – it’s probably caused by a design flaw in the window itself. It doesn’t seem like much of an issue because the moisture comes out only rarely (once every few days) but if it drips constantly then you will need to replace or repair them soon.
The reason that your old double-pane windows were able to leak during winter was due to thermal expansion and contraction of their materials, which causes air leaks between panes when temperatures change rapidly from cold weather to warm weather; often called “thermal cycling”. Your brand-new vinyl replacement windows don’t have any similar issues because there are no gaps between panes, but they may still be affected by currents from nearby power lines or other electromagnetic fields even though they’re newer than your old ones. In either case, make sure that you use a good quality anti-sealant on both sides of each window frame when applying screws for added protection against leakage.