When Sarah bumped her ladder into the living room window while hanging holiday lights, she heard a sickening crack . A spiderweb of lines spread across the outer pane. The window wasn't leaking air yet , but she knew that argon gas between the panes was probably gone. Come winter, that crack would turn into a frosty, drafty mess.
Back home, she examined the window. On the interior side, she found thin vinyl or aluminum strips holding the glass in place—the glazing beads. She slid a stiff putty knife into the seam and gently pried. Snap! The first bead broke. She learned the hard way: start at the middle of the longest side, not the corner. The second bead came off cleanly. She labeled each piece (Top, Bottom, Left, Right) with masking tape. how to replace a double pane window glass