Norwich flint: its origins and use in architecture

Flint and Norwich are inseparable. What was at first a convenient, local stone has become, over the centuries, part of the life and soul of this city. Walking through Norwich City Centre you see walls upon walls of flint in all forms; it can be left whole if one was being economical or split and fashioned into complex shapes if trying to impress.

When thinking of my first visit to Norwich, I remember wandering through small lanes with tall walls of flint either side. It was remarkable to see such large quantities of flint. I had previously only associated it with old arrowheads which appeared after soil was turned over in preparation for spring sowing. I never realized how much of it existed nor that it could be used to construct such awe-inspiring buildings.

What is Flint?

Flint with its glass-like appearance and sharp edges is reminiscent of obsidian. However, it is more closely related to jasper and chert (two other types of microcrystalline quartz).

Geologically speaking, flint is made from silica which originally came from sea creatures such as sponges and planktonic micro-organisms. It formed in areas which were once covered with water. You’ll likely find it in chalk which was once the sediment on the sea floor. The silica filled tunnels created by other sea creatures and over millions of years hardened into the flint it is today.

Because of this, you’ll find large flints which are in odd shapes called nodules. You can even find smaller spherical flints which have encapsulated echinoids such as sea urchins and sand dollars. Fossil hunters should bear this in mind – you may spot them on the beaches of Norfolk or unknowingly displayed in flint walls.

Where to Find Flint in Britain

Norfolk and Suffolk in East Anglia are well known for flint and are home to some of the finest flint craftsmen in the country. Along with these counties, you can find flint in Dorset, Wiltshire, Hampshire, Sussex, Kent, Surrey, and Berkshire.

Grime’s Grave near Thetford is a Neolithic flint mine from which tons of flint has been mined. When viewed from above, you can see over 400 uniform pits covering the earth’s surface giving it an extraterrestrial appearance. This area was well known for high quality, hard, black flint. In fact, conservation architects can pinpoint the origin of Norfolk flints to certain villages. They do this by color and characteristics. Norfolk’s flints come in a range of colors from light gray near Holt, to darker gray near North Walsham, to brown from around Fakenham, to dark black near Thetford and Swaffham. Perhaps someday I’ll be able to discern exactly where some of Norwich’s flint came from.

Small round flints can still be found on the beaches of the North Norfolk Coast. If you’re very fortunate indeed you may even find a small flint with a hole in the middle which can be made into a lucky talisman. From now on, I’ll certainly be keeping an eye out for one when I’m near the coast.

Use of Flint in Architecture

The history of extensive use of flint in architecture begins with the Romans filling walls with whole stones of flint. In Norwich, the old city walls and the walls around Norwich Cathedral are built in this way, although not by the Romans. In areas where flint is plentiful, the Romans also used it in combination with brick creating a striped appearance. The best example of this in Norfolk is Burgh Castle on the coast near Great Yarmouth.

The Saxons and Normans then used flint to build churches – thousands of churches in Norfolk alone. At first the churches were made of unsplit flint, but in the 14^th century a new technique called knapping was used. The definition of knap given to us by Oxford Languages is to “shape (a piece of stone, typically flint) by striking it, so as to make a tool or weapon or a flat-faced stone for building walls.”

Knapped Flint in Norwich

With the use of knapping, the stones could be split in half to expose the glass-like interior of the flint. There are many examples of walls which use split, round field flints. If enough money was available for constructing the building, the flints could be knapped further into different shapes. The most difficult to perfect was a square or rectangle which could then be used in a similar manner to bricks. Some of the finest examples of this are in Norwich including Bridewell Museum, St Peter Mancroft, and St Andrews and Blackfriars Halls. Some of these walls have flints which are so expertly knapped that there is no visible mortar between the stones.

Knapping of the flint also made it possible to create more decorative walls. It is said that the 58 medieval parishes of Norwich gently competed with one another which led to a variety of architectural and decorative details. I suppose this is why I never tire of examining the flint buildings I pass when walking through the city.

Flushwork and Proudwork

To add to the complexity of the designs, contrasting materials such as limestone and brick were used to make more intricate patterns. In Norwich, you can find both flushwork and proudwork. Very near my flat is St Michael Coslany which is a magnificent example of flushwork; the two types of stone are placed beside each other creating a smooth surface.

Proudwork is more rare, but can be found in Norwich if you know where to look. This decorative technique is achieved by placing the contrasting stone slightly farther out from the wall so it stands “proud” of the surface.

Flint in Norwich

I have grown to love the flint of Norwich. A cold, hard stone so brittle and dark has managed to find a special place in my heart. In Robert Macfarlane’s book The Wild Places, he speaks of the rock walls surrounding Loch Corruisk. When I read his description, I was envisioning Norwich in all its splendor, man-made, but just as beautiful. “The rock of the cauldron’s sides changes color frequently, depending upon the weather’s accent. It can be grey in cloud, toffee-colored at noon, liverish at evening, and metallic in rain and sunshine.”

It can be grey in cloud, toffee-colored at noon, liverish at evening, and metallic in rain and sunshine.

Robert Macfarlane The Wild Places

I have lived in Norwich long enough now to see it in so many different lights. The mood of the city can change because of the way the weather and its lighting work with the flint. I know my memories of this fine city and all its flint will stay with me for years to come.

If this has piqued your interest in Norwich, read more in this short introduction to the city.

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