The masonry of a building is not merely the structural material linking the building’s architectural features; the type of material used and its treatment are essential parts of the building’s character. Traditionally there was, in general, an intention to create a unity in the surface of the wall rather than to emphasise the presence of bricks or stones in the construction. Thus modern ‘ribbon’ pointing, which creates mortar joints raised from the surface of the masonry, is almost always inappropriate for an old building. Rubble stonework was very often unified by a coating of render and/or limewash. Where used, traditional specialist techniques, such as tuck pointing – where the irregularities of the bricks are first disguised by a mortar that matches their colour, and then this mortar is scored with a narrow line which is itself pointed to produce the appearance of a neat and slim joint – should be respected as an essential part of the character of the brick wall.
Regular checks should be made on the condition of the masonry and mortar joints. The mortar, traditionally lime-based in most cases, should be softer than the surrounding masonry. As such it is intended to be a ‘sacrificial’ element of the building where erosion will occur. It is usually felt that re-pointing is required when the depth of recession exceeds the width of the joint. The growth of vegetation near to and within the masonry also needs to be controlled as damage may result.
Any significant structural problems with masonry are likely to require professional involvement but the owner should watch for evidence of on-going movement such as the widening of joints. However, cracks and distortions are not necessarily a problem; in some cases they will have occurred early in the building’s history and will not be a continuing cause for concern. More detailed information can be found in 'Section 1: Masonry: Stone & Brick'.