Caring For Heritage Windows In The Winter

Stained Glass Before and After Cleaning

Before and after cleaning.

By Tanya Baleta

There’s a bit of a chill in the air this week as temperatures dip below zero. While preparing for the colder months, don’t forget your stained glass and heritage windows need a bit of extra attention. By taking a few steps to prepare for the winter, you can help ensure your historic windows will maintain their original quality.

Check For Damage

Make sure there is no damage to your windows as extreme weather conditions can exacerbate existing cracks and breaks.

Ripling lead is an indicator of lose panels of glass. In this case, it is best to call a professional.

Ripling lead is an indicator of lose glass panels. It is best to call a professional.

Be on the lookout for:

  • Movement of any glass panels.
  • Damage to the T-Bars and saddle bars, such as buckling or loose copper ties. These bars provide support to prevent bowing and sagging.
  • Damage to the sealant used to install glass panels into both stone reglets and steel frames. Inspect the adhesion of both interior and exterior surfaces.
  • Damage to any vents and weepholes.
  • Loose or missing putty. This needs to be replaced on a regular basis as stained glass windows rely on a tight, waterproof setting.
  • Broken glass.


Remove vines from the perimeter of historic windows.

Remove vines from the perimeter of historic windows.

The good news is, stained glass windows tend to do a better job of hiding dirt and grime than clear windows. However, it is important to maintain a cleaning regimine. EGD Glass recommends cleaning both the inside and outside of your historic windows at least every two years. Windows that are accessible from the ground often require cleaning once a year.

First, remove all vines and growth from around the perimeter of the windows.

Steel frames and hardware:
Vacuum the space and hinges between the frame and the window. Dust and grime can build up in this area and prevent casement windows from closing properly.

Hardware should be kept clean and in working order. Contact a professional if you notice that the hardware is not functioning properly.

Debris in the channels will prevent the window from closing properly.

Debris in the channels will prevent the window from closing properly.

Glass and lead came cleaning:
Remove finger marks and dirt with a speciality glass cleaner and a soft, lint-free cloth. Stained glass windows are especially sensitive to acids, so off-the-shelf products containing ammonia or other abrasive chemicals should never be used.

EGD Glass strongly advises that all of the above work be carried out by an accredited stained glass firm that is experienced in the conservation field. A professional will be able to help you properly clean and seal the lead cames dividing the glass panels.

Taking the time to properly maintain your stained glass windows prolongs their life, but also delays the necessity of any possible restoration efforts. Preventative maintenance ensures that future generations will be able to enjoy them for years to come.