The trickiest part of replacing glass panes in metal-frame sliding sash windows is getting replacement glass that’s sized exactly right. To replace a pane in the sliding sash of a metal-frame window, you must measure the precise length and width of the grooves in which the pane will fit.

Tip: Have the new glass cut so it measures 1/8 inch shorter than the exact groove dimensions in both the length and width. This creates a 1/16-inch gap on each side between the edges of the pane and the rabbet groove. The gap provides room for the glass to expand when the weather changes.

For this repair, you'll need just a screwdriver and the replacement glass pane.


Locate the screws on the window frame.

These screws are located at the corner of each frame.


Use the screwdriver to remove each of the corner screws.

Be sure to hold on to the screws. You’ll be using them later.


Slide out the broken pane.

Most of the broken pieces will slide right out.

Warning: When you work with broken glass, wear safety goggles as well as gloves. Small chips of glass can cause permanent eye damage.


Clean and inspect the groove around the frame.

Use a screwdriver or pair of pliers to grip any remaining pieces of glass. Be careful not to damage the groove.


Slide in the new glass pane.

The new glass should slide easily into place. If there is any resistance, stop and inspect the groove again. There is probably some glass or debris that is trapped in the groove.


Drive the screws into the corners of the frame.

Use your screwdriver to drive the original screws back in place. Be sure to tighten them enough to hold the pane back in place, but not so tight that it puts pressure on the glass itself (it’ll break).