Window Repair: Sticking or Warped Windows
There is very little that can be done to ease a warped window except by easing a few shavings where undue pressure is apparent. In many cases a window that sticks or jams is due to too many thicknesses of paint on the window or frame, and this also applies to metal windows, especially on the hinge side.
In the case ofthat are difficult to move — it should be possible to raise a lower- with the pressure of one finger — the easy movement of a difficult sash may be gained by cleaning off the edges of the sash beads and parting beads (see image below) which become thickly encrusted with paint.
If this is not sufficient a few shavings should be cut with a hook scraper from the sash frame itself. This should be done very cautiously as it is very rarely the case that a window swells sufficiently to jam it. Firm closing of a casement window may be attained by easing a few shavings from the meeting edge of the rabbet.