The Building Site

Flint

Follow the plough on the downs of the south and in the boulder clays of the east, or kick along miles of shingle beaches and you will find yourself picking up flint.

Brighton's shingle beach is full of flints with fossils within them, much prized by the Victorians. Counting the pebbles of Dungeness (or at Selsey, right), 98 per cent of which are flint, could take a while: the debris of the southern chalk cliffs (Beachy Head is striped with bands of flint nodules) has fetched up here covering 72 square kilometres and reaching 17 metres deep. Along the 18 miles arc of Chesil Beach, nine pebbles out of ten are flint. Strange to say the chalk cliffs on the south side of Flamborough Head, but not the north, are devoid of flint. At Hunstanton where the chalk once more emerges, flint is highly evident in the shingle. Less easy to explain is the flint along Loe Bar in Cornwall, a county bereft of chalk, perhaps the Isles of Scilly are the source?

Brighton's shingle beach is full of flints with fossils within them, much prized by the Victorians. Counting the pebbles of Dungeness, 98 per cent of which are flint, could take a while: the debris of the southern chalk cliffs (Beachy Head is striped with bands of flint nodules) has fetched up here covering 72 square kilometres and reaching 17 metres deep. Along the 18 miles arc of Chesil Beach, nine pebbles out of ten are flint. Strange to say the chalk cliffs on the south side of Flamborough Head, but not the north, are devoid of flint. At Hunstanton where the chalk once more emerges, flint is highly evident in the shingle. Less easy to explain is the flint along Loe Bar in Cornwall, a county bereft of chalk, perhaps the Isles of Scilly are the source?  

The amorphous remains of marine creatures and debris from the Cretaceous seas, flints may, in some places, have fossils of sponges and sea urchins embedded within them. They are found in layers in the Upper and Middle Chalk and, stolen by ice, they are secreted in boulder clay. Lumpy, rounded and often bone like, they inspired Henry Moore (he lived on the chalk at Perry Green, Herts).

But a later sculptor, Rachel Whiteread, may hold the key: her work relies upon making voids visible ­ the empty space within a house, under a bed. Some flints takes on bizarre branching shapes, like fingers or stags horns. Here the burrows of ancient crabs and lobsters, invaded by sponge-derived silica, have been turned to stone.

Flints can reach the size of a cat and may have a coat (cortex) of white or brown. Inside a nodule, colours range through yellows and reds, browns and whorls of pale grey.

Some are blue with the texture of resin,
The trap of a primeval shadow.

(from Flints, Jeremy Hooker)

Almost pure silica, any impurities give different colours and qualities. Jet black flint is the most pure and is specific to Grimes Graves in Norfolk, whilst a white flint is found only in parts of Lincolnshire. Phil Harding, notes that Bullhead flint 'is distinctive (derived from flint beds stained by overlying Thanet Sand in Kent and Essex ­ it has a green outside with an underlying orange rind) but Bullhead flint is also present in Reading Beds in Berkshire and Dorset'. He points out that, for archaeologists, most displaced flint is hard to pin down to source but better techniques for detecting trace elements may one day find unique signatures.

Because flint shines and fractures like glass, it became highly sought after by our early forbears for its hardness and capacity to chip to a sharp tough edge. Four thousand five hundred years ago people were mining 14 metres below Norfolk at Grimes Graves near Thetford, where over 400 pits are evident. This, one of Europe's earliest industrial centres, was a unique source of beautiful black flint, which was expertly fashioned into axe heads for tree felling, as well as saws, knives, axes, scrapers and arrow heads. It makes for a pocked and poignant landscape redolent of twentieth century wars, for which flint laid some groundwork. 

Before the 19th century the shaping of flint was called knacking or cracking. We now talk of knapped flint, knapen means to crack in Dutch and German. It is a practice still shared by the indigenous peoples of Papua New Guinea, Australia, parts of Africa and Turkey. In skilled hands judicious strikes produce flakes for blades and gun flints, or larger pieces for building with flattish shiny faces.

Through the Middle Ages and again in the 17th ­ 20th centuries at Lingheath and Brandon in Suffolk, flint was being mined and fashioned to make the spark to set off gunpowder, Brandon blacks are still prized for flintlock guns. The antique trade only died in the last 40 years, but family names persist at least from the 200 knappers required to keep Napoleon at bay, Carter, Edwards, Field and Snare. Many were afflicted by Knapper's Rot, the local name for silicosis. Ironically, given the likely role of sponges in the formation of flint, this lung disease was kept at bay by soaked sponges worn over the nose.

But flint has more than a walk on part to play in our history and landscape. It is a significant building stone for example in Norfolk churches, Hertfordshire walls, Wiltshire houses and Sussex barns. Lowbury Camp in Berkshire demonstrates that flint was a building material at the start of the Iron Age. There are frequent examples of Roman walls and villas as at Silchester and the fort walls of Portchester. And of the 185+ round-towered flint churches of Norfolk, Suffolk and Essex as many as 90 per cent may predate 1066. (see churches). The Normans built many flint castles: the 6-9 metre high bailey of Hertford castle is in uncoursed rubble flint, with a few knapped pieces. Later the tendency is for flint to be used for domestic building, with freestone and brick taking on the grander roles.

Not much chalk is visible in Norfolk and Suffolk, but it lies below the glacial boulder clay which captured much flint in its travels. Having this soft immediate underlay, Norfolk has two thousand years of making the best of flint in building. Conservation architects can tell where they are in the county by the type of flint: brown field flints eroded from the chalk around Fakenham, field flints from glacial outwash tend towards blue, black flint around Thetford and Swaffham, white chalk covered grey flints north of North Walsham, around Holt it is light grey, rounded beach flints come from near Wells-next-the-Sea, Sheringham and Cromer.

Within the Chilterns, where about a third of the domestic buildings have some flint, differences are noted: banded flintwork is found only in the south west, whilst the eastern scarp closer to the Vale of Aylesbury exhibits more thatch and flint, boundary walls of flint are well scattered, barns often have flint bases. More examples of knapped flint are found close to chalk quarries, since the unweathered black and white flints are easier to work. From Maidenhead to High Wycombe the old Great Western Railway had knapped flint stations.

Hard and resilient in the face of weathering, flint cobbles make good roadstone. Flint pebbles, rounded by stream action are used to good effect as paving along Much Hadham High Street, Herts. Daniel Defoe describes a little of the construction of the Fosse Way in the eighteenth century as "a laying of clay of a solid binding quality, then flintstones, then chalk, then upon the chalk rough ballast or gravel". Or Excavations along Roman Watling Street near Dunstable revealed a layer of small flints over the chalk with ditches at each side. Backbreaking flintpicking for road material from the fields, is a 19th century memory of the chalklands, as winter work to those on parish relief. In East Anglia fields, that even now 'grow' flint, are cleared by machine for roadstone, elsewhere farmers live with it, use it or heap it in field corners.

Along the Norfolk coast many houses are made of beach pebbles. In Lewes, Sussex, a few have been built by the harbourmaster with flints brought from Newhaven. (GV) Flint pebbles with holes are very common, they may still be hung in stables in East Anglia against the horses being 'hag-ridden' (bewitched) and may still be carried as talismans in Sussex. You can buy them, if unlucky on the beach, from the Hastings Fishing Museum (see superstitions or lucky stones). 

Field or 'derived' flints, are literally picked up from the earth and usually build walls where they are found. Chalk (virgin or raw) flints are quarried out of the soft rock. Glinting after rain has ensured a local name of Sussex diamonds, and building material composed of flakes of flint with chalk and brick are called bangaroush.

Flint buildings do not exist on the chalk wolds of Yorkshire and Lincolnshire, whilst beyond the towns in Berkshire and Hampshire they have predominated. From Norfolk, Suffolk, northern Essex, the Chilterns and across the southern chalk counties Adelle Wright points out that "flint buildings in these areas are said to be more numerous than anywhere else in the world".

In some places buildings are banded with flint and brick (Hampshire), in others built in chequerboard style with stone blocks between (Wilton and the Wylye valley, Wilts), diaper work offers patterns of bricks amongst the flint. Often corners, door and window openings are bounded by brick or stone, in the Chilterns this is often toothed, in Dorset brick courses present a straight edge.

Knapped flint used for building is laid randomly or in courses graded by colour, size and finish. The highest skill is to square the flint. Stephen Hart lists 54 kinds of flintwork in East Anglia, including 8 varieties of flushwork. This invention of 14th century masons, uses knapped flint and freestone to produce flat, vertical surfaces in ever more intricate patterns giving 250 years of innovative decorative work to the churches of the region. Beautiful flushwork can be seen from Elveden church in Norfolk to the church of St John the Evangelist in West Meon Hampshire, where the panels of exquisitely knapped small squared flint was done by women for the new church between 1843 and 1846 (George Gilbert Scott the elder).

The craft has withered dramatically but demand is turning the tide. Conservation architects are now active in promoting the material in its heartlands through building design guides, planning measures and courses. Some new housing is using the traditional craft to give depth to the new.

SOURCES

Round Towered Churches Society
North Norfolk Design Guide (NNDC, 1998)
Chilterns Buildings Design Guide, Chilterns Flint (Chilterns AONB Conservation Board, 2003)
Bernard and Elizabeth Orne Flint in Norfolk (Running Angel, 1984)
Adelle Wright Craft Techniques for Traditional Buildings (Batsford, 1991)
Alec Clifton Taylor The Pattern of English Building
John Easterbrook on farmers and flint use
Stephen Hart Flint Architecture of East Anglia (Giles de la Mare, 2000)
John Behague Lucky Sussex (Pomegranite Press, 1998)

Look at the web-sites for Brandon and English Heritage for information on Grimes Graves

Selsey, West Sussex Great Wishford, Wiltshire Left: House wall, Selsey Church wall Medmenham Church, Berkshire

Left: Wall at Selsey, West Sussex

Above: Horned Poppy growing in the pebbles at Selsey