The proper technique for replacing a broken window pane depends on the type of window you have. Traditional divided-light windows have individual panes set into a framework of wood muntin bars and are secured with glazier’s points and putty called glazing compound. Most older windows have a similar construction. Modern divided-light windows often have a single, large pane with a faux muntin frame that overlays the glass, or in some cases is installed between the glass panes. Replacing panes in sealed, insulated windows should be done by a professional to maintain the window’s thermal performance.
To replace a glass pane on a traditional window, first remove any shards of broken glass, then follow the steps below, being careful not to break glass as you work.
Improving Older Windows
You don’t have to replace your older windows to save hundreds on energy costs. Over time, glazing putty can crack, which allows for great thermal transfer between inside and out, bumping up your heating and cooling costs in the process. Simply re-glazing existing window panes (and re-caulking the window frames) in older homes can radically affect energy efficiency and save you a bundle of cash with very little effort.