Heritage

It is important to retain the glass heritage that we have received from the past. The windows were designed to fit with the architecture of the building. They performed several functions – among them are privacy, reduction in direct sunlight from tall windows, decorative effects, providing individuality in otherwise uniform building styles. These functions remain valid today.

Maintenance

There are a number of threats to this heritage. One is due to wear and tear. Although we recognise that window frames need maintenance, we take the continued existence of our leaded glass for granted most of the time.

• Age can lead to broken tie wires and increased flexing of the window.
• This can contribute to broken solder joints, further weakening the window.
• Loss of putty is often the cause of draughty windows and windows that allow moisture to enter.

These can be corrected simply and without great cost by re-attaching tie wires, soldering the joints, and re-puttying the windows.

Double Glazing

Double glazing is another challenge to our glass heritage. Often people are forced to choose between double glazing and leaded glass. This is a false choice. For some extra money – certainly a small proportion of the costs of double glazing - the leaded windows can be incorporated into the double glazed unit. Any double glazing company that says otherwise, just does not want the small amount of extra work in sourcing a leaded glass company to do the work. The incorporation of the existing leaded or stained glass window is simple and effective.  Example

With the increased interest in reducing energy costs, new buildings are being erected with double glazing as standard. These also can have real leaded glass included – you do not have to settle for stick on lead and coloured film. The leaded glass needs to be sealed with butyl putty if at all. The panel will not be exposed to the weather, so the glass only needs to be held securely in the lead cames without any putty.

Etched glass

Another form of our glass heritage is etched glass. This was most often found in front doors and stair windows to obscure a view or to provide privacy while allowing a lot of light into the building. In the nature of things, these large pieces of glass break from time to time. There has been a significant loss of these over time, as most insurance companies do not want to pay for a "like for like" replacement. However if your company has insured you on a “like for like” basis, you should not settle for a sandblasted replacement.

Sandblasted windows are different in character from their 19^th and early 20^th century originals. The surface is more coarse and so looks more white. The surface is such that it retains oils easily and the sandblast protection is guaranteed for seven years, while the life of the glass can be a century or more. The clear parts – the design - of the window are slightly raised and completely clear.

In an acid etched window, the design is etched into the glass, so it lies below the general surface of the glass. It is slightly marked, and so does not allow clear vision through. The obscured part of the glass is ground with fine sand, to give a satin feel to the surface, a slight grey appearance, and a natural resistance to oils.  For an example you can view this installation.

Many companies do not want to use the hydrofluoric acid required for this process, and even say it is illegal to do so. In fact, simple precautions are all that is required to use this dangerous chemical safely. It provides an unparalleled appearance and is essential in a number of applications. The costs are only slightly more than a crude sandblasted sheet of glass.

Examples of the Heritage
An associated site gives information on glass that I have experienced.  I have titled it "The Glass Appreciation Society" in an attempt at humour.  It includes pictures and other details that I have found about the glass illustrated.