Scrape away old putty and glazing points (small metal triangles). Sand the rabbet (inner ledge) if wooden. Remove any rust from metal frames.
| Glass Type | Common In | Break Characteristics | Repair Complexity | |------------|-----------|----------------------|--------------------| | | Old windows, picture frames | Large, sharp shards; jagged edges | Low | | Tempered (safety) glass | Doors, sidelights, shower enclosures | Small, pebble-like cubes (safety feature) | Medium (needs exact sizing) | | Laminated glass | Skylights, storm windows, car windows | Spiderweb cracks, but stays in place (plastic interlayer) | High (often requires full unit replacement) | | Dual-pane / insulated glass unit (IGU) | Modern thermal windows | One or both panes broken; fogging between panes | High (replace entire IGU) | broken pane of glass
Measure height and width of the opening in three places each. Subtract 1/16” – 1/8” from each dimension to allow for expansion. Take measurements to a glass shop or hardware store for cutting. Scrape away old putty and glazing points (small