The wonderful world of London stock, and its use in Rotherhithe

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
• A very brief history of London stock
• London stock in Rotherhithe
• After London stock 
• Conclusion

Introduction 

Figure 1. Rotherhithe watch-house, 1824,
St Marychurch Street

"So ubiquitous is the London stock brick in the Capital that it has tended to be despised as commonplace or, at best, ignored and taken for granted.  Yet it was the principal building material of houses in the metropolis from 1700-1840, giving them much of their distinctive character."  So starts Alan Cox's excellent article A Vital Component: Stock Bricks in Georgian London.  I am so glad that Alan Cox provided that handy little sound-bite because I was really wondering how to introduce something that might sound uninspiring, but is in fact such an important and engrossing part of how London was built in the 18th and 19th Centuries.   I had no idea, when I started doing the research for this post, that the story of London stock would be so compelling.  

Figure 2. London stock, Mills and Knight, Rotherhithe

First of all, what is London stock? London stock, also known as yellow stock, is a type of brick.  It is coloured pale brown to yellow made from a clay unique to the Thames basin area (figure 2).  Other bricks, varying from reds to purples, may also be stock bricks, but are not referred to as London stock.  To be termed London stock, the brick must be both manufactured from London clay and turn a shade of yellow when fired.  Different qualities of the brick were used for different parts of a building. 

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

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

All 18th and early 19th Century London stock is hand-made, and most of the buildings made of it in London pre-date machine-made brick.  It is made from a local clay called London clay, which is blue-black in its raw state, but weathers to a shade of brown and turns different colours when fired (i.e. when subjected to high heat to make it hard). The colouration is dependent on the clay used for making the bricks. The clay itself is a marine sediment and dates to the lowest level of the Eocene epoch, around 56-47.5 million years ago.  It is rather superb to think that the bricks that make up some of Rotherhithe's most impressive buildings are made of a mud that formed in a warm sea when this part of the world luxuriated in a tropical and sub-tropical climate with abundant forests, plants and rich animal life. The clay extends over a vast area of the Thames valley and part of its estuary (figure 3).

Figure 4. William Gaitskell House,
Paradise Street, Rotherhithe

Anything but tropical, Georgian London (1714-1830) was the place where London stock made its first appearance, and continued in use almost to the end of the Victorian period.  New laws following the 1666 Great Fire of London required houses to be built in stone or brick, and brick was favoured by most due to the prohibitive expense of stone.  During the Georgian period, London clay was found to be particularly convenient and economical for building London homes because it underlies all of London, in some places down to a depth of 150m (most of the London Underground trains were tunnelled through London clay).  London stock was particularly good for building because it hardens with both age and in response to pollutants in the London atmosphere. 

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.

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

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.

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.

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.

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.

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. 

Figure 7. London stock and polychrome brick decoration,
Columbia Wharf

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.

Figure 8. Charles Hay and Son Barge Builders

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.

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.

Figure 9. Mills and Knight Ltd, Nelson Dock

The Mills and Knight building, backing on to Nelson Dock  at 263 Rotherhithe Street, was the former engine house for Thomas Bilbe's hydraulic slipway (figure 9). Dating from around 1850 is a rather fine stock-built building with pedimented gables and a decorative course that stands proud of the main facade.  The uninterrupted warm dark yellow brick is Flemish bond (the photograph in figure 2 shows a close-up of the bricks).  With its gables, arched windows and timber paneling, the whole building has real style and a touch of creativity about it.  It looks great against a blue sky on a sunny day.

The Rotherhithe watch-house on St Marychurch Street (figure 1), which I covered in an earlier post, was constructed in 1821 and is a perfect example of one of the more humble uses of the yellow London stock brick.  Laid in Flemish bond, both the watch-house and its companion engine house   show some of the side-effects of nearly 200 years of air pollution, with some of the bricks grey to black in colour. These bricks are rather rough and ready, with uneven edges and pitted surfaces, but the courses of brick gives the building a quiet charm that regimented rows of machine-made brick or modern concrete would have made impossible.

Figure 10. Brandram's Wharf

Brandram's Wharf, at the opposite end of the size scale from the watch-house and its companion engine house, is another good example of London stock (figure 10).  A former warehouse, built at around 1870-80 and now converted to apartments, it is a four storey building made mainly of London stock but enhanced with red brick dressing and dark grey brick trim around some of the doors.  Laid in English bond, the London stock demonstrates the sort of rough surface that can result from hand-moulding and use of the clamping method of firing (figure 6).  The use of red and dark grey bricks break up the sometimes unrelieved expanses of brick used in buildings of this size. 

Figure 11. St Peter and the
Guardian Angels

The Catholic church of St Peter and the Guardian Angels in Paradise Street was build in 1902-3, and is the most recent of the buildings mentioned in this post.  Built in memory of Egyptologist Sir Peter le Page Renouf by his wife, it provides an excellent case of a building made of London stock, with coarser and finer pieces depending on location, and decorative brickwork in other colours and textures.  The main structure is built in coarse London stock, pitted with rough edges, and looks rather severe, but the main entrance to the church features a much finer type of yellow stock, with a smoother surface.  The black and white decorative bricks surrounding the door give it an added touch of style (figure 11).

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.

Figure 12. Decorative and London stock brick at the
Thames Tunnel Mill, showing the
 unmistakeble signs of air pollution

A small sample of other Rotherhithe buildings made of London stock are the Brunel tunnel engine house (Tunnel Road), Hope Sufferance Wharf (St Marychurch Street), the former engine house (twin to the watch-house on St Marychurch Street),  East India Wharf (Rotherhithe Street), Canada Wharf and Columbia Wharf (Rotherhithe Street), Charles Hay and Son barge-builders (Rotherhithe Street),  Brandram's Wharf (Rotherhithe Street), Rotherhithe underground station (Brunel Road), the Angel Public House (Bermondsey Wall East), the Catholic Church of St Peter and the Guardian Angels (Paradise Street) and the Ship and Whale public house (Elgar Street).  There are many others.   Although I find London stock warm and attractive, unalleviated  blocks of it would be more than somewhat monotonous, and the mixture of colours and styles in Rotherhithe is very welcome.


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.

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.

London stock is still made.  Although most of it is machine-made, there are also specialist brickmakers who still manufacture it by hand for use in heritage and high-end building projects.

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! 

Figure 14. The dock offices