The Lifespan of Window Glazing

Most people never think about window glazing until it starts to crack or fall out. It does a quiet but important job, and knowing what to look for can save you from water damage and drafty rooms.

1What window glazing does

In window terms, “glazing” means the glass itself and the materials that hold and seal it into the sash. On older wood windows that is usually glazing putty. On newer windows it is glazing beads, tape and sealant. Together they keep the glass secure and block air and water.

2How long glazing usually lasts

There is no single number. Putty on older wood windows often needs attention after a decade or two, and the sealants on newer windows age too. Windows that face the afternoon sun or take the brunt of storms usually wear out first.

3What wears glazing down

• Sun and heat. UV light dries out putty and sealant until it cracks.
• Temperature swings. Glass and frames expand and contract, which works the glazing loose.
• Water. Rain gets behind cracked glazing and can rot wood sashes.
• Age and paint. Old paint layers crack, and missed spots let water in.

4Signs your glazing needs repair

• Cracked, crumbling or missing putty.
• Glass that rattles or shifts in the frame.
• Drafts you can feel along the edge of the glass.
• Water stains or soft wood near the bottom of the sash.
• Glazing beads that are loose, warped or missing.

5Repair, reglaze or replace?

Small cracks may only need fresh putty or sealant. When the glazing has failed along a whole pane, reglazing brings the window back: the glass comes out, the sash is cleaned up and the glass is reset with new glazing. If the frame itself is rotted or warped, or the sealed glass unit has failed, replacing the glass unit or the whole window may make more sense.

At NB Glass we measure in person, explain whether you need repair or replacement, and give you a clear quote before any work starts. Estimates are free, and we reply the same day.