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Care of Churches

Church Window Guards

A Review of Common Types

1 Introduction

1.1 Origins

This brief guidance, dealing with the protection of church windows against vandalism, is based on one published by the Chichester DAC, which was in turn adapted from a paper prepared by Dr David Lawrence. It also draws, to some extent, on our own experience on Southwark DAC.

Note: It is important to distinguish between the protection of windows against casual vandalism, with which this paper deals, and deterring deliberate criminal entry. This latter topic is not covered by the present paper. It is a mistake to assume that window guards will prevent burglary.

1.2 Motives and Aims

Consideration of guards comes about as the result of a desire to protect windows in the best available way. Moreover, responsibility to the building is of very great importance and any system of protection used must show the greatest regard for the architecture and must do as little harm as possible to the fabric, both in the short and long term. A good test of the latter is to look hypothetically forward to happier times when guards could be taken down again. At that future time there should be little trace of there having been guards in place. The process should be 'reversible'.

It should always be established at each church whether it would be feasible not to have any guards at all. All guards compromise the architecture to a greater or lesser extent; the only real solution to the problem of vandalism is to attempt to re-educate those responsible; to involve them in the life of the church and so on. There is evidence to support the theory that attempts at providing security actually encourage the acts of destruction. For example, if some, but not all windows are guarded, the attacker's interest is drawn to those unguarded.

2 Wire Guards

2.1 Galvanised Ferrous Metal

Whilst in many ways wire guards can provide a useful and relatively inexpensive solution to the problem, the following points should be taken into account:

(a) Although traditional-looking in some circumstances, they can also call to mind an industrial building, or maybe a jeweller's shop, and can seem inappropriate for a place of worship.

(b) The feeling that they are out of context is exaggerated if a silver/grey finish is used, but greatly reduced if they are finished in black.

(c) Unless regularly maintained, they will rust and this can cause serious staining to stonework. The damage can be irreversible, short of major stone work repairs. Cases are known where rust has penetrated 1.25 inches (32mm) into the stone-work.

(d) They can be visible from the inside, looking out. In the case of leaded lights, the building becomes a 'cage'; and in the case of stained glass, the lighted painted windows can be compromised by a grid of unwanted lines.

(e) If fitted over whole multi-light windows, including mullions, tracery, etc., the appearance is dreadful: they should normally be fitted to each light separately.

(f) They reduce the transmitted light, although they do not altogether prevent the cleaning action of rain.

(g) They do not give protection against someone armed either with an air-gun or with a hammer in one hand and a spike (e.g. screwdriver) in the other.

2.2 Non-Ferrous Wire Guards

The additional points to make about guards in non-ferrous wire are as follows:

(a) All the points listed above apply equally to copper guards. The only difference is that the staining will be green rather than red. (For a glaring example of this, look at Tewkesbury Abbey, which has been seriously disfigured by the use of copper.)

(b) The cost of guards in copper or stainless steel is higher than those in galvanised steel.

(c) Stainless steel wire guards secured with stainless steel fittings and screws eliminate the staining problem and usually cost less than polycarbonate.

(d) A word of warning about stainless steel guards is that, because the raw material is more expensive than galvanised wire, manufacturers will sometimes skimp on the specification and produce a guard lacking in rigidity.

2.3 Powder-Coated Wire Guards

The technique known as powder-coating gives a good protection to ferrous wire guards and offers a longer life-span than the galvanising process. There is a real architectural advantage to the black finish of powder-coated guards. The outer surface of stained glass naturally has an overall black finish and so the guards to some extent 'disappear'.

The best form of wire guard in most circumstances is one made of stainless steel and powder-coated, or otherwise finished, in black.

3 Polycarbonate Guards

3.1 Incorrectly Designed

When shields of polycarbonate sheet were introduced, a number of serious mistakes were made, both in the design of the guards and the fittings. Amongst these were:

(a) It was fitted in large sheets, covering stonework as well as glass, which is aesthetically and technically inappropriate in nearly all cases. Sometimes sheets of only 4mm thickness were used.

(b) Due consideration of the large coefficient of expansion (0.5%) was not given, so that buckling and damage were occurring. Although polycarbonate is virtually indestructible by the action of external forces, it can break itself up, if restrained, by the internal forces of expansion.

(c) The buckling led to dreadfully distorted reflections of light.

(d) The fittings used were of poor quality materials, such as aluminium.

(e) The sheets were sealed into the wall or into frames, thereby producing unventilated cavities. Often the frames were of poor quality material. (Possibly the function of protection against damage was confused with that of double-glazing.) Sometimes the polycarbonate was introduced as a misguided alternative to restoring a leaking window.

(f) The large sheets, fitted by contractors with all their equipment and man-power, were difficult to remove for access.

3.2 An Attempt at Overcoming the Technical Problems

The design of polycarbonate guards can be greatly improved, technically and visually, if the following standards apply:

(a) The guards are made of 6mm thick polycarbonate sheet or a heavier grade if the windows are especially wide.

(b) The guards are cut to exactly the same shape as the glazing; all stonework is exposed and the area of reflection is reduced to a minimum and confined to areas where, visually, glass is expected anyway.

(c) They are fixed on brackets of unpolished stainless steel with fittings of stainless steel and nylon. The fittings allow for the expansion of the polycarbonate. No frames are to be used. The fittings need to be secure but removable for maintenance.

(d) The guards are made in small panels which can be removed for access if needed and which allow a free flow of air all around, thereby not encouraging the problems of condensation or the growth of organic matter. Each panel of polycarbonate might be, say, only 36" x 18" and, conceptually, these small units can relate well to the traditional materials often used in older churches. Thus the modern material can be less at odds with the architecture of the building.

(e) This design - see (d) - also allows for expansion with temperature. The spacing between adjacent panels should be 10mm.

3.3 Remaining Problems

There remain drawbacks, as follows:

(a) The reflection of light gives the building an unpleasant 'blind' look. This is somewhat more acceptable if the plane of the sheet material is preserved and the reflections undistorted. The problem is not so apparent at the more sheltered windows of the church.

(b) The polycarbonate sheet cannot be cleaned in the same way as glass and can be deliberately scratched or disfigured with graffiti.

(c) Unlike wire guards, the long-term properties of polycarbonate are not known for certain. Possibly they may last for a few decades but they may become more opaque with the passage of time. An investment in these might well be not as sound as an investment in stainless steel wire guards which are likely to put in a significantly longer period of service.

4 The Option of Not Guarding

The deliberate policy of leaving windows unguarded is a sensitive matter and each case must be taken on its merits. At the two extremes, leaded-lights could well be left unguarded, whereas particularly rare or beautiful stained glass should be guarded. Again, guarding is more appropriate in some localities than in others.
For this approach to be effective, it must be accompanied by an untiring but rewarding campaign aimed at helping the offenders. Damage is often caused by a young age-group: this area of activity, touching as it does on sociology and pastoral matters, is beyond the scope of the present paper, but it may be possible in some circumstances to encourage youngsters to respect and value their surroundings.

5 Supporting Measures

Whether or not guards are fitted, the following supporting measures are paramount:

(a) The church should have in safe keeping a thorough photographic record of the stained glass, preferably in the form of colour slides, both of overall views and details. This procedure is being increasingly recommended by the insurance companies and might one day become mandatory. Some archival material is held at the National Monuments Record Centre (NMRC) of the Royal Commission on the Historical Monuments of England (RCHME) at Kemble Drive, Swindon, SN2 2GZ. It is both more feasible and less costly to repair a stained glass window if photographs exist.

(b) The churchwardens and cleaning volunteers should be made aware of the importance, following a breakage, of collecting and saving every fragment of broken glass and lead, both from inside and outside. This needs to be 'written into the constitution' so that the principle is not lost as personalities change. Also, they need to ensure that potential missiles are not left lying around outside the church.

(c) The church should review its insurance cover.

6 Conclusions

6.1 Preferred Methods of Protection

No design of guard is perfect. The only completely acceptable state of affairs would be to have unguarded windows in the context of a society whose members are not reduced to causing damage. It must also be recognised that certain situations dictate that a particular form of protection is the only applicable method, for example if there is persistent damage from air-gun pellets or where the internal view of a particularly sensitive window would be spoilt by an external metal grille then polycarbonate may be the only effective form of protection.

However, in general, our order of preference is:

1) No guards at all, where this is practical;

2) Stainless-steel wire guards (with black finish) - our normal preference;

3) Black finished steel wire guards;

4) In particular circumstances, correctly designed polycarbonate guards.

Note: The local planning authority may need to be involved if a material alteration is made to the appearance of the building, especially if the church is listed or is in a conservation area.