Property: The craftsman: Caught Knapping: Cutting, or knapping, flints is a Stone Age skill, an expert tells Caroline McGhie

MUCH of Bernard Bartrum's craft is neolithic. He learnt it from the former custodian of Grimes Graves, the ancient flint mines on the borders of Suffolk and Norfolk. Bernard is a flint knapper: he cuts, or knaps, the stones as they come off the field or out of the quarry. He is also a skilled maker of flint axeheads, of the kind used by prehistoric hunters and farmers to fell trees and skin deer.

Some of his tools, too, are more often seen in museums. For certain types of flint knapping and for fine finishing, Bernard uses pieces of deer antler, which jostle with old coal-breaking hammers in his plastic bucket. His wheelbarrow is full of 16th-century lime mortar, which he has been crushing so that he can re- use it on the walls he restores.

'Lovely stuff,' he says. 'Modern cement mortar is terrible. It has no suction with the flint at all. I have just been to see a flint building at St Albans which is ruined because the flints don't like cement mortar. You don't use a steel hammer for neolithic reproduction work. It takes off a different sort of flake. The steel makes a very deep shave.'

To demonstrate, he turns the mottled blue-white knob of a flint over in his hand and cracks it with a steel hammer. A sliver of flint splits away revealing the almost black core, slightly swollen like the shape of a mussel shell. 'That is called the bulb of percussion, and you get that with a steel hammer,' he says. 'With deer antler you get a flat cut.'

The discarded slivers might be used as 'gallets', little stoppers in a wall between larger knapped flints, designed to give the darkness of the wall greater density. He is making safe the ruins of a church at Roudham in Norfolk, so that villagers can continue to hold occasional services among the roosting pigeons.

The church walls are random flush work, which means that each cut flint is placed haphazardly with its flat black core facing outwards. There are chips and dimples in the flints, showing where the hammer has worked. Were this 'fine' flush work, each one would be smooth as marble.

The skill of flint knapping lies partly in being able to 'read' a flint. You or I might hit a flint for hours and never achieve a break. The core inside the white, crusty outer cortex is made of silica, which has no grain at all and is only slightly softer than diamond.

The experienced knapper will first look for the angles before he cuts it with a single strike. 'I look for a certain kind of platform,' Bernard says. 'It is no good striking a flat surface. It can get very technical explaining how different angles respond, but basically it's the angles you go for.

'Some people say you can turn the flint round in your hand, tapping it all the way, and you get a clean break, but it doesn't work. That way you just send shock waves through it.'

Flint that has been freshly dug has a slight moisture content and is easier to work than flint that has been exposed for many years. Those that have frost damage simply disintegrate when they are cut. You can tell a damaged flint by tapping it: a good one rings like a bell; a bad one sounds muffled. 'Most flints have fossils inside them because they were originally formed round fossils, usually sponge fossils,' Bernard explains.

The finest square flints will take at least 20 minutes each to cut and prepare, while a rough-cut flint will take around five minutes - 'But some houses actually have very few flints. Some of those along the coast that I've worked on have only around 20 flints per square foot.' For a suitably weathered look to new flint, a solution of fresh cow dung can be painted on to encourage the growth of moss and lichen.

Flint as a building material lasts for thousands of years, provided that water doesn't leak in through the mortar - something much more likely to happen with modern cement mortar than with flexible lime mortar. Bernard, one of few craftsmen with the knowledge and skill to work with flints in this country, believes a revival is under way: 'A lot of younger architects are coming round to the old craft view of things, so things are changing for the better.'


Purcell, Miller Tritton, 14 St Clements Street, Winchester, Hampshire SO23 9HH (0962 868027), specialise in historic building work. Also have offices in Norwich, Colchester, London, Ely and Canterbury.

Bernard Bartrum, SPAB Fellow, 88 Hillcrest Avenue, Toftwood, East Dereham, Norfolk NR19 1TD (0362 696939), see above.

Richard Deane, 11 Ashfield Road, Salisbury, Wiltshire SP2 7EW (0722 330170), is a stonemason based at Salisbury Cathedral who also works on other historic buildings.

Glaven Pits, Holt Road Garage, Thornage, near Holt, Norfolk NR25 7QB (0263 740 848), supplies flints hand-picked from the quarry at pounds 45 per tonne.

H G Clarke, 2 High Street, Weston Underwood, Nr Olney, Bucks NK46 5JS (0234 711358), supplies clunch at around pounds 180 per tonne.

The Lime Centre, Long Barn, Morestead, Winchester, Hants SO21 1L2 (0962 713636), runs one-day courses on the history and practical application of lime at pounds 95 plus VAT per day.


'Conservation of Clay and Chalk Buildings' by Gordon Pearson, published by Donhead. Price pounds 30.

'The Nature and Subsequent Uses of Flint, Volume One' by John Lord, available from Green Lane House, Little Livermere, Bury St Edmunds, Suffolk IP31 1PY. Price pounds 5.50 inc p&p.

'The Masters of Flint' by A J Forrest, available from Terence Dalton Ltd, Water Street, Lavenham, Sudbury, Suffolk CO10 9RN. Price pounds 9.95 hardback, pounds 7.95 paperback.

'Craft Techniques For Traditional Buildings' by Adela Wright, published by Batsford. Price pounds 19.99.

The Society for the Protection of Ancient Buildings, 37 Spital Square, London E1 6DY, has relevant pamphlets.

(Photograph omitted)

Suggested Topics
Arts and Entertainment
Call The Midwife: Miranda Hart as Chummy

tv Jenny Lee may have left, but Miranda Hart and the rest of the midwives deliver the goods

Arts and Entertainment
Legendary blues and rock singer Joe Cocker has died of lung cancer, his management team as confirmed. He was 70
music The singer has died aged 70
Arts and Entertainment
Maisie Williams looks concerned as Arya Stark
Arts and Entertainment
photography Incredible images show London's skyline from its highest points
Arts and Entertainment
'Silent Night' last topped Classic FM's favourite Christmas carol poll in 2002
Arts and Entertainment
Rhys says: 'I'm not playing it for laughs, but I have learnt that if you fall over on stage, people can enjoy that as much as an amazing guitar solo'
musicGruff Rhys on his rock odyssey, and the trouble with independence
Arts and Entertainment
Krysia and Daniel (Hand out press photograph provided by Sally Richardson)
How do today's composers answer the challenge of the classical giant?
Have you tried new the Independent Digital Edition apps?
Arts and Entertainment

ebooksNow available in paperback
Arts and Entertainment

Shenaz Treasurywala
Arts and Entertainment
Jason Watkins as Christopher Jefferies
Arts and Entertainment
Star Wars Director JJ Abrams: key character's names have been revealed
Arts and Entertainment
Pharrell Williams won two BBC Music Awards for Best Song and International Artist
Arts and Entertainment
Mark, Katie and Sanjay in The Apprentice boardroom
Arts and Entertainment

Film The critics but sneer but these unfashionable festive films are our favourites

Arts and Entertainment
Frances O'Connor and James Nesbitt in 'The Missing'

TV We're so close to knowing what happened to Oliver Hughes, but a last-minute bluff crushes expectations

Arts and Entertainment
Joey Essex will be hitting the slopes for series two of The Jump


Who is taking the plunge?
Arts and Entertainment
Katy Perry as an Ancient Egyptian princess in her latest music video for 'Dark Horse'

Arts and Entertainment
Dame Judi Dench, as M in Skyfall

Arts and Entertainment
Morrissey, 1988

Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    A Christmas without hope: Fears grow in Gaza that the conflict with Israel will soon reignite

    Christmas without hope

    Gaza fears grow that conflict with Israel will soon reignite
    After 150 years, you can finally visit the grisliest museum in the country

    The 'Black Museum'

    After 150 years, you can finally visit Britain's grisliest museum
    No ho-ho-hos with Nick Frost's badass Santa

    No ho-ho-hos with Nick Frost's badass Santa

    Doctor Who Christmas Special TV review
    Chilly Christmas: Swimmers take festive dip for charity

    Chilly Christmas

    Swimmers dive into freezing British waters for charity
    Veterans' hostel 'overwhelmed by kindness' for festive dinner

    Homeless Veterans appeal

    In 2010, Sgt Gary Jamieson stepped on an IED in Afghanistan and lost his legs and an arm. He reveals what, and who, helped him to make a remarkable recovery
    Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

    'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

    Yazidi girls killing themselves to escape rape and imprisonment
    Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

    Ed Balls interview

    'If I think about the deficit when I'm playing the piano, it all goes wrong'
    He's behind you, dude!

    US stars in UK panto

    From David Hasselhoff to Jerry Hall
    Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

    Grace Dent's Christmas Quiz

    What are you – a festive curmudgeon or top of the tree?
    Nasa planning to build cloud cities in airships above Venus

    Nasa planning to build cloud cities in airships above Venus

    Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect
    Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

    Clocks, rifles, swords, frogmen’s uniforms

    Surrounded by high-rise flats is a little house filled with Lebanon’s history
    Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

    Four months after the bombardment, Gaza’s wounds are yet to heal

    Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
    Gastric surgery: Is it really the answer to the UK's obesity epidemic?

    Is gastric surgery really the answer to the UK's obesity epidemic?

    Critics argue that it’s crazy to operate on healthy people just to stop them eating
    Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

    Homeless Veterans appeal: Christmas charity auction

    Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
    Pantomime rings the changes to welcome autistic theatre-goers

    Autism-friendly theatre

    Pantomime leads the pack in quest to welcome all