How to Replace Plastic Snap-In Window Glazing

Put on safety glasses and work gloves before beginning the repair process. Some windows may have peeling paint chips which can fly up and cause injury.

Examine the top of the exterior side of the window where the glass meets the wood. Identify the small flexible strip that runs along this area. This is the old snap-in glazing and is typically white unless it has been previously painted.

Insert a flat-head screwdriver at the left corner of the old snap-in glazing until it begins to lift up. Slide the screwdriver under the glazing along the top of the window to snap it out of place. If the glazing is very old, it may crack or crumble. Grasp the old glazing and pull it away from the frame.

Repeat the process on the bottom edge of the window glass to remove the glazing there as well. Remove the old snap-in glazing on each side of the window glass.

Place the end of a new piece of snap-in glazing firmly in the left side of the window glass with the small lip facing toward the side of the window. Press in firmly on the center of the glazing until you feel it snap into place. Move your hands outward and continue pressing until you reach the window corners.

Repeat the process to install new snap-in glazing on the right side of the window.

Hold a new piece of glazing up to the top of the window and use a utility knife to cut the corners to an angle that fits flush with the top of the side glazing strips. Repeat the process to trim the corners for the bottom glazing piece.

Press the top and bottom glazing strips into place with your fingers just as you did with the sides.