There are at least 2000 church buildings in Scotland currently used for worship.
The Church of Scotland alone maintains about 1400 of them. No two are identical, but common factors in their design and construction allow them to be grouped into families, and common problems identified. Some are very simple, little more than sheds, and others extremely complex. Often the complexity of a building is more apparent than actual, this is typically seen when extensive decorative features are applied to a simple structure. Even where there is real complexity, the building is usually made up of a conglomeration of simple units. This module will later show how a simple building can be dressed up in different ways, and then how more complex buildings can be built up from simpler units. Before that, however, this article will describe, briefly the types of construction which are characteristic of Scottish churches, and which are common to a number of types.
Most Scottish churches are stone-built.
There are several techniques for building in stone. In almost all the wall is solid, with inner and outer faces brought to a 'fair face', that is to a vertical or near-vertical flat face (omitting details). There is usually a space between the inner and outer faces (the 'core') which is filled with less-well finished stone. In such buildings the walls are commonly fairly thick, and may be supported externally by buttresses, which serve to keep the walls vertical, and also, in some cases, to resist the outward pressure imposed by a roof.
The degree to which the stonework is cut to a regular shape varies widely.
In very early churches the stone was often cut into almost cubic blocks, used on both the inside and outside faces of the building. Subsequently dressed stone was often confined to the outer walls of the building, less regularly cut stone being used on the inside walls, which were usually plastered. In many churches built from the 17th to the early 19th centuries the outside walls were also built of less regular stone, covered with a layer of harl to keep water out. In such buildings the margins of windows and doors, and the wall-heads, were usually made of dressed stone. Sometimes dressed stone was used in this way with an exposed skin of less-regularly dressed stone. In the later 19th century there was a revival of the use of dressed stone for internal walls, and where this was not the case brickwork was sometimes substituted for stone for the internal skin and core of the wall.
After stone, brick is the commonest material for church construction.
Brick can be used in the same manner as stone, to make a solid wall, but in the 20th and 21st centuries it has often been used in two other ways. In walls intended to support a roof, the so-called cavity-wall is often used, with inner and outer skins separated by an air gap, bridged by metal ties. In other cases the roof is supported by steel, concrete or laminated timber frames, and the brickwork has only its own weight to support. In that case a single-brick wall may suffice. Concrete blockwork (breeze blocks) may also be substituted for brick for internal walls. In a few instances the external walls are built of concrete blocks. In some late-20th century buildings the walls are almost eliminated, and the roof carried down almost to ground level, in what are called A-frame buildings.
Of the other materials used for wall construction the most important are timber and corrugated-iron.
Some buildings, or parts of buildings, were built in the late 19th and early 20th centuries with timber frames, with the spaces between the timbers probably infilled with rendered brick. Sometimes thin pieces of wood were applied to the exterior of a building to give the impression that it was timber-framed. Much commoner was the use of corrugated iron (usually in practice galvanised steel) to form walls, on a timber or steel frame. In these cases the corrugated iron was used both as a skin and as a load-bearing material.