This is a slightly longer post than usual, so I've listed the contents
at the top, and provided a figure number for each of the photographs as some of them are referred to more than once in the text. As always, you can click on any of the photographs to see a bigger image.
Contents:
Introduction
Contents:
- Introduction
- A very brief history of London stock
- London stock in Rotherhithe
- After London stock
- Conclusion
Introduction
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| Figure 1. Rotherhithe watch-house, 1824, St Marychurch Street |
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| Figure 2. London stock, Mills and Knight, Rotherhithe |
London stock had many benefits to
the builder, and today it stares out at us from every sort of London
building, from the lofty heights of Bedford Square in WC1 down to the humble Rotherhithe watch-house (figure 1) on St Marychurch Street. We
have huge quantities of London stock in Rotherhithe, It was the most
popular London building material of the 18th and early 19th Centuries,
and continued to be used right up until the late 1800s, when it was
still the cheapest building brick available. Many of the 19th Century granaries and wharves are good cases. Those that stand out as particularly fine are Nelson House and the Old Police Station. There is also a lot of it on the Thames foreshore near the Surrey Docks Farm, where
it was bulldozed following the massive destruction of the bombings in
the Downtown area of Rotherhithe during the Second World War. I will talk more about Rotherhithe examples of London stock below, but first a look at the brick itself, and how it was used.
A history of London stock
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| Figure 3. The distribution of London clay, used to make yellow London stock. http://en.wikipedia.org/wiki/File:Geological_map_of_London_Basin.jpg |
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| Figure 4. William Gaitskell House, Paradise Street, Rotherhithe |
During
the Georgian period, when new housing was erected in the fields around a much smaller
London in places like Berkeley Square and Russell Square, the London
clay could actually be excavated from beneath those very fields, in the
form of "brickearth." So before building started, the clay was
excavated and the bricks were manufactured in situ. Then the
ground was levelled and the houses were built. As Cox puts it, "London's Georgian houses were largely built
from the clay on which they stood" (p.61). Some areas were not
suitable for extracting clay from the sites on which buildings were to
be erected, and in these cases the brick was brought in from other
locations. Many London building
contractors owned their own brickearth fields on the outskirts of town,
or further afield in Middlesex and other counties, and this could be
transported cheaply by river and more expensively by road.
Rotherhithe's London clay, being covered in several metres of Thames alluvium, was probably seated too far down for it to be cost-effective to dig down to it, and during the Georgian period her bricks were probably brought by river from elsewhere to be erected on the site. Later on, during the mid to late 1800s, it is entirely possible that it was extracted, along with other less useful sediments, during the excavation of the numerous enclosed docks that defined 19th Century Rotherhithe.
A considerable amount of space and
labour were required for the extraction of the clay. John Middleton,
writing in 1798, states that one million bricks were produced per acre
for every foot in depth of brickearth with an average depth of four
feet. In her 1992 book on building materials, Linda Clarke says that it took between six and eight brickmakers
and labourers to produce around a million bricks in a four monthly
period over the spring and summer, which would produce 33 "fourth rate"
houses. House ratings were standardized in the 1774 Building Act, and a fourth rate was a relatively small house that occupied less than 350 sq ft and were worth less than £150.00 in ground rent. During the Georgian period mould sizes were frequently standardized,
making it easier for architects and builders to plan. Initially most
buildings were built using a brick laying pattern ("bond") called
English bond, but this was superseded by Flemish bond, with English bond
becoming briefly fashionable in some homes in the early 1800s. Bonds were initially adopted to provide stability to walls, but cost and fashion were also factors.
To
my surprise, once the clay was extracted from the ground it was mixed
not only with sand, but with sifted domestic refuse, and street sweepings of grit and cinder, known as town ash or, for some reason, Spanish." This contained high proportions of ash and cinders and these
acted as an internal fuel and speeded up the firing process. Once
mixed, the bricks were placed in an open-ended mould on a board with an
iron shape attached to it (the "stock board" that gave its name to stock
bricks), to give the brick its distinctive form. The bricks were then
dried in the open air for up to two weeks before being burned. Most
bricks fired at the site where they were to be used were not fired in
proper kilns, but were heated through using the "clamp" method. Clamps consisted of bricks stacked over flues and surrounded by other bricks or clay to seal them in. When fuel, usually coal or wood, was lit, the bricks started to heat from the bottom up, and could take up to six weeks to burn through. The best bricks came from the centre of the stack whilst the outer ones often had to be re-fired. The ash
added to the clay, acting as an internal fuel, speeded up the process
and therefore required less fuel, which reduced costs.
For the discerning house owner, higher quality versions of London stock were available. Grey stock was also
yellow, but was more uniform in both shape and texture, and was preferred for facing buildings where
appearance was important. Another type of clay was marl or "malm," which
sat at a lower level in the London clay beds than those that made the
standard London stock. With lots of stones in it, which had to be
removed, it cost nearly twice as much as grey stock.
After the 1840s, even though London stock was still the cheapest brick type in London, it became fashionable to add courses of red stock to improve the appearance of a building and provide it with some decorative flourishes. Red stock could be imported from outside London, from Sussex, Kent and Berkshire (made from a sandy loam they were called "rubbers" and "cutters"), but it was also made from clay found within London overlying the clays used for yellows and greys. The lack of lime meant that the red oxide was not suppressed and these clays produced red brick. Because they were specially used for decorative effects they tended to be fired in a fixed kiln so that the quality was much better than standard stock. We have some examples of these, too, in Rotherhithe, including Columbia Wharf, the Dock Offices, Brandram's Wharf and the Thames Tunnel Mill. At the other end of the scale second hand stock bricks were used for fill, where they could not be seen, or to build houses for the poor.
At the
same time, low-cost London stock was never more popular for the building
of granaries, factories and stores, as well as low cost housing.
Improvements in brickmaking technology and in kilns improved the overall
quality of the bricks being produced, and it was still being used
frequently in the concealed parts of buildings.
After the 1840s on-site brick manufacture was actively discouraged, as it was both disruptive and unattractive.
Rotherhithe's London clay, being covered in several metres of Thames alluvium, was probably seated too far down for it to be cost-effective to dig down to it, and during the Georgian period her bricks were probably brought by river from elsewhere to be erected on the site. Later on, during the mid to late 1800s, it is entirely possible that it was extracted, along with other less useful sediments, during the excavation of the numerous enclosed docks that defined 19th Century Rotherhithe.
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| Figure 5. A small sample of brick bonds used in English buildings. From Wikipedia, where a much larger selection can be found: http://en.wikipedia.org/wiki/Brickwork |
There
are slightly different types of London clay, and depending on
their mineral composition, they dry to a different colour when fired (or
in brickmaking terms, "burned"). The clay preferred for London houses
has a lot of lime in it, which gives it its yellow colour. In order to
achieve clearer shades of yellow, white washed chalk was sometimes added
to it. Upper layers of the London clay have more red oxide in it, and
no lime, so this burns to a red colour instead. Of course today the lighter colours are
often concealed under a layer of charcoal-grey or black due to air pollution. Much of the Rotherhithe stock brick is surprisingly pollution-free given the amount of industry in the area when most of those buildings were built, and I am guessing that they were cleaned up during the regeneration of the area. The Thames Tunnel Mills bricks, however, are a notable exception, showing considerable grey coating (figure 12). In the case of houses, particularly expensive ones, facing bricks, which
are those visible on the outside, were usually well shaped and smooth.
Industrial buildings were faced with rather less high quality bricks.
Bricks used for fill, where appearance was not of any concern, were
often very uneven and were unsuitable for use as facing.
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| Figure 6. London stock showing many small cavities caused by the burning of the inclusions in the brick mixture. This contrasts with the much better quality black decorative brick. Brandram's Wharf. |
Because
of the use of town ash, the air drying and the clamp method, the
quality of shape and consistency of the London stock could be very
variable. The more ash in the mix, the more pitting and pock marks, because the ash
burned out during the firing process (figures 6 and 13). The clamping method, where
60-120,000 bricks were burned in a single go by being stacked over tunnels that were filled with fuel (usually wood) and covered in bricks or clay,, had a 10% wastage rate, on
average, but the loss was balanced by the efficiencies of mass
production and, where they were manufactured on the building site, by
the savings on transportation.
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| Figure 7. London stock and polychrome brick decoration, Columbia Wharf |
After the 1840s, even though London stock was still the cheapest brick type in London, it became fashionable to add courses of red stock to improve the appearance of a building and provide it with some decorative flourishes. Red stock could be imported from outside London, from Sussex, Kent and Berkshire (made from a sandy loam they were called "rubbers" and "cutters"), but it was also made from clay found within London overlying the clays used for yellows and greys. The lack of lime meant that the red oxide was not suppressed and these clays produced red brick. Because they were specially used for decorative effects they tended to be fired in a fixed kiln so that the quality was much better than standard stock. We have some examples of these, too, in Rotherhithe, including Columbia Wharf, the Dock Offices, Brandram's Wharf and the Thames Tunnel Mill. At the other end of the scale second hand stock bricks were used for fill, where they could not be seen, or to build houses for the poor.
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| Figure 8. Charles Hay and Son Barge Builders |
After the 1840s on-site brick manufacture was actively discouraged, as it was both disruptive and unattractive.
London stock in Rotherhithe
23 Paradise Street, formerly the old police station and now labelled William Gaitskell House, was built in 1814. (figure 4) With its symmetrical Georgian proportions, it is very typical of many contemporary and earlier London buildings, and similar to some along Jamaica Road, but it stands out in Rotherhithe peninsula as one of the few classic late Georgian buildings to survive. The quality of the brick is actually not much better than many of the commercial buildings, but the multicoloured stock bricks, including London stock, were laid with considerable care, in Flemish bond, with thick mortar helping to create even rows. The ground floor semi-circular and first and second floor flat segmental arches are made of a much higher quality brick, reflecting their more important structural role. This is a really lovely building and it is a considerable relief that it survived when so many others did not.
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| Figure 9. Mills and Knight Ltd, Nelson Dock |
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| Figure 10. Brandram's Wharf |
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| Figure 11. St Peter and the Guardian Angels |
Perhaps the most elaborately decorated of all of Rotherhithe's stock-built entities is the Dock Office complex, which were built in 1893 to serve the Surrey Commercial Docks (figure 14). Probably the most important building in the day to day operation of the docks, it was located at their main entrance, by Canada Dock (now Canada Water). The main structure is built of London stock, but it is liberally accessorized with red brick details and other architectural embellishments.
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| Figure 12. Decorative and London stock brick at the Thames Tunnel Mill, showing the unmistakeble signs of air pollution |
After London stock
As well as the growing fashion for variation in brick work, both colours and textures, a trend that wa significantly facilitated by the expansion of the rail networks, the development of ever more sophisticated machines for taking over tasks that had formerly been done manually changed the way in which brick was produced.
From the 1890s fletton bricks began to take over in popularity, and these are what you see on most modern residential and commercial buildings today. Made of Oxford clay, fletton bricks, named after Fletton in Cambridgeshire, are also known as London bricks, named after the London Brick Company. They were particularly popular in the 1960s and early 70s. Hanson PLC, the company that now owns the form er London Brick Company works, estimates that over 5 million homes have been made out of fletton brick in Britain. It's not overwhelmingly attractive stuff, when compared with London stock and some of the lovely older bricks, but it was relatively inexpensive.
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| Figure 13. Carpark wall at the Hilton, made with old London stock, clearly showing some of the holes left by the burning of matter included in the clay during firing, and modern mortar. |
There is also a very good market in second hand London stock, from buildings that have been taken down, which are purchased to repair or extend existing buildings or to build new buildings in areas where the old brick dominates. Some of the walls on the Rotherhithe Street side of the Hilton, erected in the 1990s, are made with old stock brick using modern mortar (figure 13).
Conclusion
This post covers buildings that were built between 1814 and 1903, a span of nearly 100 years. London stock was used for nearly a century before this and is still in use today. It is one of the brick types that defines London's appearance. Not confined to any one form of building type, it was used for residential, ecclesiastical, municipal and commercial projects, and has proved to be very resilient to both weathering and pollution. London stock is as fundamental to our city as our rain, and a lot more attractive!
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| Figure 14. The dock offices |
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