STAINED GLASS is an almost universal feature of our churches. It is able to transform the experience of their interiors through the combined effect of light and colour while still conveying inspirational messages of faith in ways unique to this medium.
Several techniques have been developed to make stained glass. It can be self-coloured or comprised of plain material fused with coloured glass to give it lustre. It can be painted or stained with special pigments which bond with it and allow detail to be applied on top. Etching and surface-cutting give different effects while various surface textures are possible, refracting light in different ways.
TINTED GLASS is also commonly found, particularly in churches and chapels of the smaller reformed denominations.
Meanwhile PLAIN GLASS allows full natural light to enter and will make the interior less gloomy than if it was otherwise dominated by dark stained glass of questionable quality.
REPAIRS may be needed as a result, for instance, of vandalism or because time and weathering have affected the appearance of the glass or the strength of the framing which holds it together. This framework is traditionally formed in lead, as being soft enough to support the panes of glass without causing them to break through the metal expanding and contracting with change of temperature. Lead so used is inherently long-lasting - normally 100-150 years- and many lead-framed windows of lesser age have never needed much attention.
As such windows age, however, the H-shaped strips of lead known as cames can tend to lose some of their integrity, causing obvious buckling and bulging and threatening the safety of the whole window. If you notice signs of such trouble, ask an experienced glazier for advice. South-facing windows can be prone to this problem, particularly when solar heat builds up between protective secondary glazing and the main window. Always make sure that this gap is designed to include ventilation.
When any work affecting stained glass is contemplated you should always seek advice from an accredited practitioner in the art. Some will both repair windows and undertake new work while others are specialist restorers.
Repairs to windows made of plainer glass can be entrusted to less specialised glaziers with a good reputation for this type of work.
Larger windows are sometimes braced by iron rods which should not be allowed to rust.
Little maintenance is normally required.
Most leaded windows are made with small channels and weepholes at the base to collect condensation and remove it from the building. Keep them free of blockage. If it is necessary to clean the inside, 'painted' face of stained glass, use distilled water with cotton wool and certainly nothing chemical or abrasive.
PROTECTION from malicious damage is, however, a serious issue facing many congregations. Wire mesh grilles and polycarbonate or laminated glass sheeting, separately or in combination, are now recommended as the best means of protection.
Unless the vandalism extends to use of sticks and air guns, mesh grilles on their own should be adequate. They will be more easily maintained than glass or polycarbonate sheeting which can cause the overheating described above and may spoil the external view of the windows through reflection. Whichever method is used, the panels should be purpose-made to fit the size of each individual window, with no overlapping of stonework or other framing.
Fixings should always be non-ferrous to remove the risk of rust. Mesh guards will last longer if ordered as 'powder coated', preferably in black as hiding them best in daylight against the dark glazing behind.
You should be aware that much stained glass has high artistic value. Unless expertly advised otherwise, it should be treated as such and examined for its condition at least every 10 years.
All your pictorial stained glass should likewise be photographically recorded, in colour, to help its repair and restoration in case of damage.
For fuller advice on maintaining, protecting, repairing and replacing church window glass, a very useful reference is the Church of Scotland booklet Church Windows. See Window and Door Openings module.