Window glazing refers to the panes of glass that make up the windows; it doesn't refer to a coating put over the glass, like glazing a donut. A double-glazed window is a window that has two panes of glass rather than one. These are a very popular option for windows today and they offer a number of benefits, including added insulation and sound absorption or sound blocking. If you're considering double-glazed windows versus standard single-glazed, you might note a few questions to consider and then ask a contractor about these if you need more details.
1. What happens when dust and dirt accumulate between the panes?
If you've ever seen double-glazed windows with a buildup of dust or dirt between them, this often means that they simply need servicing. Double-glazed windows need to be properly inserted into the window frame and then sealed so that no dust or dirt can settle between them. Poorly manufactured windows may have small openings that allow dust to settle, or the seal may have degraded over time. Double-glazed windows can be cleaned by specialists who can take the window apart, clean it thoroughly, and then give it a new seal after it's been reassembled.
2. Do double-glazed windows add to home security?
If someone were to break the first pane of glass on your windows, the sound might alert you or neighbors of a potential intruder so that you could call police. However, the amount of security offered by double-glazed windows will typically depend on the type of window panes you choose. Security or toughened windows are thicker and therefore harder to break than normal glass. If you're concerned about home security, be sure you ask for toughened or security glass that is more durable than standard window glass, rather than assuming that double-glazed windows in of themselves make your home resistant to intruders.
3. Does double-glazing mean protecting the home from bothersome sunlight?
Because double-glazed windows often insulate a home better, you may assume that they also keep out bothersome sunlight. However, windows are rated by what is called visible light transmittance, which refers to the amount of sunlight they allow to pass through. The ratings range from 0 to 100; if a window is rated at 0, it allows no light to pass through. If you're worried about sunlight because of migraines or other sensitivities, or because you live in the tropics or an area where you need more protection from the sun, choose double-glazed windows with a low visible light transmittance rating.