Although brickwork can be very hard-wearing, deterioration may occur due to poor repairs, maintenance or alterations. For example, leaking gutters can cause joints to erode, the use of inappropriate cement mortar instead of lime hastens crumbling, and tree root damage leads to cracks or bulging.
A Short History
Bricks may be made from various materials, but are most commonly of clay, which normally contains a small amount of lime or iron oxide. Traditionally, they were made by hand in timber moulds. Brickwork was constructed using lime or earth mortar; unlike modern cement products, this allowed the building fabric to ‘breathe’, which is important with old, solid walls to control dampness.
The pointing profile (finish of the mortar joints), bonding (arrangement of bricks) and brick size and colour have varied over time. These features can help, therefore, to date buildings.
Brickwork was little used in this country until the late Middle Ages. By Tudor times, however, it rivalled stone in popularity. Bricks tended to be irregular in shape and size, but the shapes could also be sophisticated, as seen in the twisted chimneys characteristic of this era. Walls were often decorated with diamond patterns of different coloured bricks (‘diaperwork’).
The more consistent shape and size of Georgian bricks reflects advances in manufacturing methods. Grey stock bricks and yellow London stocks were fashionable at the end of this period. Soft, rubbed bricks could be laid with very fine joints for high-quality work. A less expensive alternative was to create the illusion of thin joints using a technique called ‘tuck pointing’. Brick production became mechanised from the 19th century and by the end of World War I, modern cement mortar, rather than lime, was widely employed for constructing brickwork.
Repair and maintain
Repair might entail selective work to the joints and/or bricks. Sometimes only minor repointing of eroded joints is necessary. On buildings pre-dating 1919, lime mortar, not cement, should usually be used.
Bricks can frequently be carefully removed and then reversed to hide decay. Tile stitching may be an appropriate repair for cracks in old brickwork, especially where horizontal joints are no longer in line. If the joints between tiles are kept fine and care is exercised, the repair will gradually weather in over time.
Coloured mortar (‘plastic’ repairs) may be used to build up decayed brick faces, but skill is required to achieve a good long-term colour match. Thin brick slips have been used as an alternative, but they possess an inherent structural weakness.
Only bricks that are severely damaged should be cut out and replaced. Exact replication is very difficult but there are a number of good suppliers producing new handmade bricks at reasonable prices.
Replacement bricks should match the existing ones as closely as possible in size, colour, texture and durability and should be laid in the same way. It is better to leave replacement bricks to blend in naturally over time than to attempt to tone them in.
Be cautious about the use of secondhand salvaged bricks. They may be underfired and unsuitable for external work, or can sometimes be damaged.
3 of the best new handmade bricks
Bulmer Brick & Tile makes facing bricks to order in a range of colours, using the rich clay dug on its site, POA (01787 269232; bulmerbrickandtile.co.uk)
York Handmade Brick’s handmade range comes in 10 colour blends, which can be mixed, POA (01347 838881; yorkhandmade.co.uk)
HG Matthews produces wood-fired bricks using a method dating from the 18th century, POA (01494 758212; hgmatthews.com)
- Repairs: Simpson Brickwork Conservation (07956 155411; simpsonbcltd.co.uk)
- Repairs: Mathias Restoration (01582 872178)
- Consultant: Gerard Lynch (01908 584163; brickmaster.co.uk)
Images: SPAB (top); Robert Sanderson (below)