Britain's historic paving

We cherish fine buildings. To cherish fine streets and paving we need to record them, and to understand the materials used, their qualities, how they were laid and how to care for them.

Granite setts at the carriage entrance to Nottingham station and river cobbles at Merton Street, Oxford. Photos by Robert Huxford.

The delight that we derive from traditional paving is by no means the exclusive preserve of obsessive anoraks. Tourist blurb extolling the qualities of historic cities will inevitably refer to the charm of their ‘cobbled streets’; Gold Hill, Shaftesbury and countless stretches of remnant setted streets provide the setting for film sequences and television adverts as shorthand for heritage and distinctiveness.

Paving is not a trivial item. Without paving there would be no towns or cities. Rain turns heavily trafficked soil to mud, and soon after into an impassable quagmire. One of the main purposes of paving is simply to enable safe and efficient passage. Public health is a second concern. Prior to the arrival of the motor car, streets rapidly accumulated animal wastes and refuse. Resilient, easily cleaned, waterproof paving was the key to maintaining an acceptable environment within a town. There is the matter of aesthetics: there have been times when introducing flagged paving was thought to add to the dignity and sophistication of a town, and was a matter of considerable pride.

Traditional paving includes not only stone, but a wide range of pre-concrete manufactured materials, such as brick pavers and cast-iron kerbs. Like vernacular buildings, it can tell us so much about local distinctiveness and Britain’s complex geology.

Unlike vernacular buildings, however, the story of traditional paving concerns not only the use of locally-sourced materials, but also the importing of more durable or economical materials from elsewhere. Whereas building materials are to a degree protected from the weather, paving must survive rain, snow, frost, heat and traffic. Lucky is the town that has such durable materials close at hand. Local distinctiveness in paving is therefore a mix of geology and the prevailing transport systems.

Larger ships, and engineered roads, canals and railways, led to better or cheaper paving from more distant areas finding their way into local streets; and not just from Britain, but from parts of Europe, Asia and South America. Cornish and Devon granites and Purbeck stone from Dorset was transported by coastal ships. Canals and railway lines aided the spread of Staffordshire blue bricks and Mountsorrell granite. Scoria bricks produced by the Tees Scorriae Brick Company in Middlesbrough from foundry slag can be found along the east coast, and even in Canada, Mexico and Costa Rica.

Paving in Britain goes back into prehistory, with timber paths such as the Sweet Track, surfaces paved with river cobbles found in the entrance to hill forts, and major roads such as the iron-age Sharpstone road in Shropshire. The Romans were prolific pavers, but it is in the medieval period that we begin our story.

Misconceptions about medieval roads abound. The most persistent is that they were merely rights of ways. In fact, those making journeys on horse or foot or conveying freight needed investment in physical infrastructure, both in roads and bridges. Goods were often carried by road in preference to water transport. Taynton stone from the Upper Thames for Eton College was carried by road to Henley before being ferried down the river. Two-wheeled carts were ubiquitous in lowland England, supplemented by pack-horse trains and four-wheeled wagons.

While roads were far from perfect, a range of improvements reduced the effort required from horses (from the 13th century horses, not oxen, were used for haulage in most parts of England), and hence expenditure on horse-feed. Ditches were dug alongside roads to improve drainage; many complaints related to the failure to clear them. On floodplains causeways were raised at considerable cost; at Abingdon 300 men were at work digging ditches and constructing the causeway in the summer of 1416. At Swarkestone a mile-long causeway survives, pierced by medieval arches. Stones, sand, gravel and clay were applied to road surfaces.

Money for the repair of the road from Smithfield to Highgate was to be spent on wood and sand. Large amounts were spent: in 1427 Sir Gerard Braybroke left £100 (a labourer earned 3–4d a day) for repairing ‘foule wayes’. He also paid for the construction of Barford Bridge, one of a dense network of bridges which demonstrates the sophistication of the medieval road system. Particular attention was paid to roads near important buildings. For £133 the master mason, John Lewyn, agreed to renew defective roads near Brancepeth where he was rebuilding the castle.

New challenges arose in the 16th century, as coach travel began for the first time to be fashionable for men as well as women, and as heavier wagons came into use, replacing carts. The turnpike trusts beginning in the 17th century continued to use existing methods. At first they achieved little, but by 1750 impressive progress was being made through more consistent application of old technology and the reduction in gradients. Better roads meant that springs could be used in coaches and travel became much quicker. The benefits for freight were taken in reduced costs rather than shorter times.

Outside towns, roads were improved for transport and economic reasons. Inside, civic pride and environmental health were more important factors, as paving facilitated cleaning. Roads in Anglo-Saxon towns were metalled and by the 12th century they were paved. From the 13th century, tolls were collected on travellers to pay for paving. Professional paviors were employed in many cities: in 1315 the Corporation of London retained six master paviors, and by 1479 they had formed a guild.

There is some evidence, both documentary and archaeological, of the wide range of local materials used. The bridge accounts reveal that Rochester Bridge was paved with ragstone; excavations revealed a cobbled street at Chester; and at New Winchelsea a rare example of medieval paving survives under the Pipewell Gate, consisting of Tilgate stone set on edge.

As at Chester, for centuries many streets had a drain down the middle. Pedestrians could be protected by bollards, as many 18th-century images show. But by that date stone slab paving was being constructed, creating extensive level paved areas for pedestrians, adding dignity and refinement to a town, and greatly facilitating promenading in fashionable clothes. In Bath, large-format Pennant stone paving slabs were introduced. In London, York paving stones were common; leases signed in the 1770s for houses in Bedford Square specified that a footway was to be formed with ‘Yorkshire paving’ and the carriageway paved with ‘Scotch Granite or Square Jersey Pebbles’ (setts). Roadways in such towns often consisted of setts until macadam became widely used in the 19th century.

From the middle ages to the 19th century, disease was thought to be transmitted through the air by miasmas. Hence street cleaning was seen as vital, and paving assumed a key role in the public health movement. In the 21st century the health challenges are very different: obesity and appalling air quality mean that we need to encourage people out of their cars to walk and cycle. An attractive, high-quality public realm is of great importance if people are to lead healthier, more active lifestyles.

It is as much the design and layout of paving as the materials themselves that enhance the street scene. A ‘grammar’ of use can be detected in different contexts. Villages would rarely be ‘pitched and paved’ throughout, especially in areas where stone was unavailable or unsuitable. Flagstones might be used in the churchyard and outside some buildings, but cobbles would predominate. Grand streets in towns would have regularly laid flagstones, making elegant corners with wedge-cut stones. Crossovers would be paved in smaller units, less likely to crack under cart wheels. Rectangular setts, laid parallel with the kerbs, would create drainage gullies and laid laterally would provide the carriageway, laid to McAdam’s principles.

While carriageway materials would usually be granite from a variety of sources, such as Aberdeen, Mountsorrel or Devon, other stones were also used, such as diorites from the Channel Islands, basalts or the harder sandstones and limestones. Brick pavers were used in areas such as the midlands, the Weald of Kent and Sussex. Woodblock was used in some cities to help deaden the noise of iron-shod hooves and wheels. Lanes would usually have a shared surface, with a central drainage channel. Yards would use a lesser-grade stone, more roughly dressed.

In the UK, despite the widespread closure of smaller quarries providing paving stone, high-quality stone can still be sourced. Caithness stone (with its dark hues, slight rippled texture and ability to be precisely cut in relatively large units) is available, as is red granite, also from Scotland. Of course the versatile York stone is widely used, and latterly Pennant has re-emerged, mainly from South Wales. Some others from the palette are often available in small quantities: creamy Purbeck stone, green/grey Forest of Dean stone and Ashburton ‘Marble’ are examples.

Twenty-first-century challenges

The skills of the street mason in working with the characteristics of the stone are in very short supply. Specialist stone suppliers can be an invaluable source of information when designing or reinstating paving schemes. Investment in skills is essential if we value our quality streetscapes.

Traditional paving was laid as a ‘flexible pavement’, with the stones or bricks bedded in sand or grit, and sometimes pointed with tar. The design worked well with traditional traffic: horses, carriages and wagons, which tended to drive the setts into the bedding, helping to consolidate them, and the iron-shod hooves and wheels, which would wear them smooth. Modern traffic causes very little surface wear, but applies very high sideways forces, which can rotate or dislodge the setts.

A further challenge is from street-sweeping vehicles, which in the UK vacuum rather than sweep. The suction draws out the bedding material in which the setts or flags are laid, destroying their stability. In continental Europe the street cleansing machines are much more likely to be limited to sweeping only. Such machines create less dust, which may benefit air quality.

There may be heavily trafficked areas where traditional flexible laying methods are unsuitable. Here the setts must be bound together as a rigid surface with a high-strength mortar, laid on a steel-reinforced concrete foundation. It is also possible to limit the weight of vehicles to protect the surface.

Traditionally, gaps between slabs and setts were narrow. Today when paving is relaid the width is often increased inappropriately. In some examples there is more mortar than stone. Wide joints create a surface that looks ugly and is uncomfortable to walk on.

Mortar spread over the surface of setts or flags can take several decades to wear off. Such work should be condemned and the mortar chemically removed.

It is almost impossible to paint white or yellow lines on sett paving without the paint spreading and creating an embarrassing eyesore. There may be no need to use lines at all. Government has suggested using restricted parking zones in preference to painting yellow lines. The ‘Traffic Signs Manual’ provides guidance on this. Some streets are so narrow that any parking would materially obstruct the way: obstruction of the highway is an offence under s137 of the Highways Act 1980. In these streets it is appropriate to ask whether the additional traffic orders are necessary.

If lines are deemed necessary, they should be the narrowest available under the ‘Traffic Signs Regulations and General Directions’ (that is, 50mm and not 100mm). The TSRGD only requires lines to be yellow, not chromium yellow. White centrelines have been shown to increase vehicle speed: they can be dispensed with altogether. Parking spaces can be delineated with studs.

Sometimes utility companies excavate traditional paving and reinstate temporarily using bitumen, taking the excavated material to landfill. The permanent repairs are then undertaken using setts of a different size, finish and type of stone, leaving a permanent scar.

Different stone types are often mixed inappropriately, or arbitrarily sourced types of stone are introduced that were never used locally or are being used in non-traditional ways. It is important to record what materials are used in a street and why. Without this knowledge it will be difficult to maintain the street’s distinctiveness.

Granite setts and Yorkstone flags are often regarded as the definitive heritage surfaces, even though many areas would have been surfaced with rammed earth, stone macadam or similar. Here, bitumen macadam surfaces, surface dressing or clear-coated stone surfacing may be truer to the original than a new surface of setts or flags.

One of the biggest threats to traditional paving is a concern about litigation over trips and falls. But the primary danger in streets is moving traffic, not the paving. Block paving, according to research commissioned in preparation for the 2007 government guidance Manual for Streets, reduces traffic speeds by 2–5 miles per hour. It is likely that sett paving will reduce speeds further through the psychological effect of travelling on a surface that is different to regular bitumen macadam.

Highway authorities have a duty to ‘maintain the highway’ under s41 of the Highways Act 1980. This generally means inspecting and repairing the fabric of the existing highway to a reasonable standard. But traditional paving may not be unsafe. A hidden rocking slab or a small trip hazard in an area of otherwise smooth paving may not be obvious, and can act as a trap for the unwary. But a large area of continuous uneven paving will be entirely obvious, and irregularities will be expected and anticipated. For this reason, the paving may not be hazardous. There is no duty on the highway authority to create the surface of a bowling green. The common law places on road users a duty to have regard to their own safety, and to take the road as they find it.

The Equality Act 2010 introduced the ‘public sector equality duty’, and a requirement under specific circumstances where disabled people are affected to make adjustments to enable access: ‘where a physical feature puts a disabled person at a substantial disadvantage in relation to a relevant matter in comparison with persons who are not disabled, to take such steps as it is reasonable to have to take to avoid the disadvantage.’ The act proposes alternatives: (a) removing the physical feature in question, (b) altering it, or (c) providing a reasonable means of avoiding it.

In some areas there can be a compromise by sensitively creating areas of smoother paving, such as stone flags, an overlay of a bound material or even gravel. In other areas such measures may not be possible, and the question will arise: does an adjustment to the access to an historic environment that involves its partial destruction constitute a reasonable adjustment?

Ageing populations will increase pressures to make adjustments. Does this age group really demand changes that would deny to future generations the historic environment that they enjoyed in their youth?

Documentation on the nationwide picture of traditional paving is sparse. English Heritage’s Streets for All (2005) series was one of the few attempts to identify paving traditions and sources on a regional basis. There have been individual studies of local areas, often by conservation officers who have seen the need to highlight the traditional materials and patterns of use, in order to inform the design of public realm schemes. But there is little systematic analysis, or focus, for collecting small-scale local studies.

The British Geological Society has made major advances through the production of county stone atlases under the Strategic Stone Study, which catalogues much of the building stone in the UK. Through the efforts of Michael Heap of the stone supplier CED, British Geological Society head office near Keyworth, Nottinghamshire, is home to a geological pavement: a permanent exhibit of some 40 different paving types used in the UK. Wonderful though this is, there are many more types of paving to record and cherish.

There is a need for something akin to an atlas of traditional paving in the UK, with maps showing the distribution of paving traditions, existing and historic sources of materials, and the main locations of ‘imported’ stone (for example, towns with extensive areas of York stone, Pennant and Caithness, far removed from those sources). The atlas would need to be richly illustrated with examples of the materials and, importantly, how they are laid. Geological maps would be included, explaining the rich and complex distribution of materials. Our preliminary feasibility studies have indicated that the British Geological Survey is interested in collaborating in this project. Conservation officers and civic societies might be interested in adding local knowledge to it.

Few people today can identify the different types of material used in traditional paving, or the different techniques used in laying. Nor is there a record of what we have. Both the knowledge and material is being lost. We cherish fine buildings; let us cherish fine streets and paving in the same way.

This article originally appeared in IHBC’s Context 152, published in November 2017. It was written by Richard Guise, David Harrison and Robert Huxford. Richard Guise is an architect and planner with Context4D. A co-author of English Heritage’s Streets for All, he specialises in the public realm and characterisation. He co-author of Characterising Neighbourhoods. David Harrison is a retired House of Commons clerk and medieval historian. In the House of Commons he served in many positions, including as clerk of the environment, transport and regions committee. He has published many articles on medieval architecture and transport. His book on The Bridges of Medieval England was published by OUP in 2004. Robert Huxford is director of the Urban Design Group.