With the beads off, the IGU fell inward. She caught it just in time. Underneath, she found old, rock-hard glazing putty and tiny plastic shims. Using a heat gun (on low!) and a chisel, she scraped the frame clean. “This is the worst part,” she muttered, picking dried putty out of her hair.
Replacing the glass in a double-pane window—technically known as an (IGU)—is a precise task that involves removing the entire sealed unit rather than just one pane. Because these units are factory-sealed with insulating gas (like argon) to provide thermal efficiency, they must be replaced as a single component once the seal is broken or the glass is cracked. Essential Tools and Materials how to replace a double pane window glass
Sarah’s first instinct was to run to the hardware store. Smartly, she stopped. She measured the entire window frame and took a photo of the manufacturer’s sticker on the spacer bar between the panes. She learned that for sealed double pane units, you don’t buy “glass.” You buy a sealed Insulated Glass Unit (IGU) —two panes fused together with a spacer. Her local glass shop cut custom IGUs for $85. With the beads off, the IGU fell inward
