How to Replace One Glass in Dual-Pane Windows

Do-it-yourselfers can make their own double-pane glass repairs.

Installing energy-efficient windows is a good way for homeowners to save money on energy costs throughout the year. Dual-pane windows are made with two panes of glass with a 1/2- to 3/4-inch space between them in the frame. This construction allows a layer of air to act as an insulator, which prevents the transfer of heat between the interior of the home and the exterior. Though the dual-pane construction makes repairing a single glass pane more complex, you can still do it with the right techniques and tools.

Things You'll Need

• Replacement glass
• Blanket
• Utility knife
• Hacksaw blade
• Screwdriver
• Isopropyl alcohol
• Vinegar
• Spray bottle
• Buytyl sealer
• Silicone caulk

Instructions

1. Measure the size of the glass that needs to be replaced. This should match the original glass as closely as possible in terms of width, height, thickness and any additional coatings applied to the original glass. Order the replacement glass from your local home improvement store.

2. Remove the window frame from the opening by twisting or turning the slider mechanisms on the window then pulling the sash outward. These mechanisms may vary in different types of windows

3. Lay the frame on a padded surface, such as a tabletop covered with a blanket. Remove the butyl seal from around the glass with a utility knife. Scrape off all pieces of the sealer from around the frame.

4. Use a hacksaw blade to gently work the glass out of the frame. Remove the screws that hold the glass in the frame and set them aside. Remove all broken shards of glass from the frame and discard.

5. Clean the new glass with a solution of isopropyl alcohol, vinegar and water to remove all dirt and grease. Mix 1 cup of isopropyl alcohol, 1 cup of vinegar and 1 cup of water thoroughly. Pour the mixture into a spray bottle and clean the glass, especially around the edges where fingerprints are prone to show up. Then apply a thin bead of silicone around the frame.

6. Mount the replacement glass into position inside the frame and ensure that the spacers are properly placed to hold the panes apart.

7. Replace the butyl seal around the glass then caulk around the window with silicone sealer.

8. Wait for the sealer to dry for 24 hours before re-installing the window into its opening.

Tips & Warnings

• The glass in dual pane windows generally goes into the rubber about 1/2-inch so add 1 inch to the width and height measurements for the glass to account for this additional amount, that is, 1/2-inch on one side plus 1/2-inch on the opposite side.

• Any dirt or fingerprints left on the interior of the glass will remain there permanently. Take special care to clean all interior surfaces before installing the glass into the frame and wear gloves to avoid leaving prints on the glass.