In one or another of its compositions, concrete has been known and used since Roman times. Its use in Scottish church building, however, has been almost entirely confined to the period since the Second World War, catching up with its general use in nearly every other type of modern structure. Occasionally and especially in the Highlands, some older churches have been built using stone rubble in a concrete matrix.
In other simple and inexpensive buildings concrete blockwork has been used in place of brick and should be similarly maintained. Note that where the more porous breeze block forms an inner skin it will hold and retain water if allowed to get wet, requiring considerable time to dry out.
Concrete is made up of water, cement, gravel and sand in proportions depending on its role in the building and it can be finished in many ways, ranging from replicating the character of rough timber shuttering to a high degree of polish.
When reinforced by steelwork, normally in the form of rods or mesh, it can carry larger loads over greater distances and has been used structurally in this way in most of our modern concrete-built churches.
The most likely signs of concern will be cracking and spalling which is similar to the surface flaking of stonework, previously discussed. Spalling, however, is likely to prove more troublesome when it affects reinforced concrete, usually signifying that water has got through to the reinforcement underneath. This action will in turn have caused rusting and expansion of the metal, forcing off the thin concrete layer above. The whole process may have begun with the cracking of part of the concrete surface and might have been avoided by earlier and less expensive repair.
Remedying concrete faults needs special professional advice and you should first contact your appointed architect or surveyor if a regular general inspection is not imminent. See Professional Help module.