What to Do When the Seal Goes Bad on Double Pane Windows

What Are Double Pane Windows?

• Double pane windows are constructed with two panes of glass in each frame. The space between the panes is filled with air, or a gas such as argon or krypton. The panes are then hermetically sealed to keep the insulating material from escaping. Once the air or gas leaks out, the window loses much of its energy efficiency. The seals also keep moisture from entering between the panes. If moisture enters, it will cause fogging or condensation.

Can You Repair a Bad Seal Yourself?

• If you're looking for an inexpensive, "band-aid" type fix, you can simply caulk the seal to close the leaks. Use a good-quality siliconized acrylic latex. After it's cured, it's waterproof and resistant to mildew. Siliconized acrylic latex has excellent adhesion qualities. Follow the manufacturer's directions for the best results. Keep in mind, though, that repairing the failed seal in a double pane window this way won't restore it to its original state. It won't have the insulating properties it once had.

What to Do if the Windows Are Under Warranty

• Check the paperwork that came with the windows if you're not sure about warranty coverage. If your paperwork is misplaced or lost, check the frame near the bottom of the glass for the manufacturer's identification and a manufacturing date or date code, then contact the window manufacturer. A representative will confirm the warranty and advise you how to get proper repairs.

What to Do if the Windows Are Not Under Warranty

• Fortunately, as long as the frames are in good condition, the windows don't need to be replaced. You can get them repaired by finding a professional glass repair service. A professional can come out, drill holes in the sash, clean the inside of the glass and re-plug the holes. You can also remove the sashes yourself and take them to a window specialist to restore them to their original condition.