If you have a broken window in your home, you need to ensure the glass gets repaired properly and repaired quickly. Even a small crack can easily spread, and the glass might shatter when you least expect it; this can be dangerous, and replacing the window may be more costly than if you have the glass repaired when it just has a crack. Since most homeowners don't need to deal with a broken window or glass repair very often, note a few things you may need to know if the situation arises and then discuss these with a glass repair technician if you need more information before they visit.

Specialty glass and windows 

If you have specialty glass for the windows of your home, you need to note this to a repair person when you call, as they may need to use different tools and chemicals to repair certain types of glass. Some window glass is made with a metal oxide to reflect sunlight off the window, keeping the home cooler. The same type of glass can be used with the metal oxide on the inside, to keep the home warmer during long winter months. Gels that are used to fill in cracks and chips should have the same mixture of metal oxide so the crack isn't visible when repaired. 

Tinted glass also needs a certain mixture for the same reason; the wrong gel will make the repair noticeable. Double-paned glass may be filled with argon rather than plain air, and your installer will need to bring argon with him or her to refill that gap after the pane is replaced. If you're not certain the glass you have, ask the technician if you should look somewhere on the window for a mark or serial number that would help them find the type of glass used.

Size of crack

Note the size of crack or chip when you call for repairs; if the chip has gone through the window entirely, it may not be repairable. If the crack is very long, it might also be beyond repair. If you can't describe the damage, ask if you can take a picture with your smartphone and send that. Very often a technician can tell from a picture if the damage can be repaired, or not.

Upgrade

If the windows are beyond repair and need to be replaced, consider an upgrade. Thicker glass can mean better insulation for your home, or you might consider the metal oxide glass, as mentioned above. You might find that an upgrade is not as expensive as you assume, and since you'll need new windows anyway, you can save on the cost of labor if you waited to upgrade your windows at a later time.