Older houses may contain windows with a single pane of glass which can separate from the window frame over time. This is usually caused when the putty used to seal the window wears out with age. When this happens the window pane must be repaired, to seal air leaks and keep the glass from falling out. The typical way to fix glass when it separates from the frame is to reapply putty, but other methods can be used as well.

1. Step 1

   Clean the old putty from around the glass and the window sash. Scrape the old putty off the glass using a scraping tool.

2. Step 2

   Apply new putty to the window glass and sash. Grab a handful of putty from the container and knead it until the consistency is even..Roll the putty between your hands to create a bead and then press it into the glass along the edge.

3. Step 3

   Use a putty knife or flat edge tool to press the putty into place. Slide the putty knife along the glass and sash, at a 45-degree angle, using a smooth motion to evenly spread the putty.

4. Step 4

   Remove any access putty and let it set for at least two days. Use a scraping tool to remove any access putty after it has dried. (Make sure it is completely dry before doing so.)

5. Step 5

   Use caulk or sealant to fix the glass separation. Clean old putty from the glass using a scraping tool and then run a bead of caulk along the glass and sash. Allow the caulk to setup for at least 24 hours.