Glazing

Defect

Cause/Action

Cracking of glass in steel windows

As steel rusts it expands and can exert considerable pressure on the glass. Rusting is often caused by water finding its way down the back edge of glazing putties or by penetrating an unprotected gap between the window and reveal. If the frame is badly rusted or distorted it will be simpler to replace it. To replace only the cracked pane strip the putty, take out the glass, remove the rust, treat and reglaze.

Rainwater penetration around glass due to cracked, loose or missing glazing putty or beads

This is normally because of age or lack of maintenance. If the glass is held in with beads, these are often incorrectly bedded and will allow rainwater to find its way in. it will be necessary to reglaze.

Glass loose

If window frames are rotten or are distorted making it difficult to close the window, the forcing and subsequent efforts to move them may eventually cause the glass to fall out, especially if the glazing putties are defective as well.

Misting up of sealed double-glazing units

This is caused by moisture penetrating the sealed unit. The glazing system should allow for such moisture to drain away. The sealed unit cannot be repaired and will need to be renovated.

Leaking through roof lights

There are many possible causes including defective lead flashings, cracked glass, rusting of steel sections, defective putties or breakdown of rubber seals.