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authorities believe it stemmed from the boat-building traditions of Scandinavia,
others that it has affinities with the pointed arch of Gothic design (see p. 874).
More probably the form evolved from practical needs and limitation of
knowledge as did the similarly-shaped early corbelled stone structures of areas as
far apart as Mycenae in Greece or the Celtic oratories of western Ireland.
In early cruck construction the basic timbers, the crucks, were massive whole
or split tree trunks, the lower edges of which were fixed into the ground in pairs
at intervals in the long sides of a rectangular building—the interval was generally
some 3.5–5m (12–16ft)—and the narrower tops were then bent over to be
fastened together in the centre so forming an apex to the roof. A long horizontal
timber, the ridge piece, was extended along this whole roof, the crucks being
affixed to it. Parallel to the ridge piece were other slenderer poles and these were
crossed at right angles by more timbers. The interstices were filled with branches
and mud and covered on the exterior by moss, thatch or turf.
The great drawback to the single-storeyed cruck building was its lack of
headroom, as it had no vertical walls, so the design was further developed into
two-storeyed buildings as the crucks were taken up higher. The next stage was
to extend horizontal tie beams across the interior and beyond the crucks to
attach to horizontal timbers, at right angles to the tie beams, which would
carry the roof and act as the summit of the now vertical walls. Gradually cruck
structures became more advanced and practical. The lower ends of the crucks
were set into low stone walls or timber sills instead of directly into the ground.
The crucks were shaped before use, a pair forming a symmetrical arch. More
complex roof designs followed (see pp. 865–6).
Timber-framing
In regions of northern Europe, especially where hardwoods were available in
quantity, as in England, a more sophisticated method was evolved in which split
timbers were attached together to form basic framework for a building, which
would have vertical walls and a gabled roof (see Figure 18.1 for an example of

this type of structure). The panel spaces between such framing were then filled
with other materials—wattle and daub, laths and plaster or brickwork. This type
of construction is also known as half-timbering, because the tree trunks were
halved or cleft, not complete logs. The trees were stripped of their bark and
soaked for a year or more in water to season the wood before use.
Many designs of timber-framed structures were developed over the
centuries. In England there were two fundamental types: the box-frame and
the post and truss. The first of these was built with horizontal and vertical
timbers crossing at right angles and fastened together to make box shapes. In
the latter designs, vertical posts supported a truss, that is, a group of strong
timbers formed into a framework within the triangle of the roof gable.
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Figure 18.1: Timber-framed inn. The Feathers Hotel, Ludlow, Shropshire, late
sixteenth century.
Photograph Doreen Yarwood.
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The simplest type of truss is a triangle formed from three beams and, in
building, grew out of the use of the gabled roof. The Greeks of Hellenistic
times invented the truss, finding the triangle to be a rigid form. The earliest
surviving description of a truss is in one of the volumes of De Architectura by
Vitruvius, the Roman architect and engineer of the first century BC. In
timberframe construction there is a horizontal timber (a tie beam) and two
sloping timbers fastened together at the apex. The weight of any roof creates a
thrust which attempts to push the upper part of the walls outwards which is
counteracted by the horizontal beam tying the sloping timbers together. In later
centuries the theory of this single rigid triangular truss was elaborated, as in
the classical trussed bridge design in which combinations of triangles were
used. Later still, in the nineteenth century, with the availability of cheap, strong

iron and steel, large, complex trussed roofs were constructed to cover railway
sheds and stations (see p. 893). In modern times, vast and complicated trusses
have been created to enclose great auditoriums (see p. 879).
Whatever the design of timber-framing there was a similarity of basic parts
and methods of construction. In order to exclude the damp, the framework
was usually erected upon a low wall of more impermeable building material,
such as stone or brick. Upon this footing were laid horizontally baulks of
timber called sills or plates. Strong vertical posts (the studs) were then mortised
into this sill and their upper ends tenoned into another horizontal plate.
In most types of timber-framed buildings the upper storeys projected over
the ones below. This overhang is called a jetty. When a building was jettied on
all sides, additional support was provided for the structure by internal cross
members known as dragon beams which extended diagonally from the centre
to the corners of the upper floors. Jettying had several purposes. Of importance
on limited town sites, it gave a greater area of floor space to the rooms of the
upper storeys. The lower storeys were protected by those above from rain and
snow at a time when there were no down pipes or gutters. Jettying also gave a
more balanced stability to the upper floors themselves.
Oak timber-framed buildings did not require preservative sealing. The black
and white effect which many surviving structures show is due to a
nineteenthcentury custom of painting them with a coal derivative tar with the
plaster panels whitened for contrast. Many owners are now stripping their
timber-work back to its original silvery hue.
Timber-framed buildings were largely prefabricated and they may, without
too much difficulty, be taken down and re-erected as has been done in a
number of instances, for example, on open-air museum sites. Originally the
larger timbers were cut and shaped on site but smaller ones were made in a
carpenter’s workshop and brought to the building. The infilling was put in
floor by floor, so completing the structure as the building was erected. A form
of decoration known as pargeting, using abstract patterns or representational

figures, was sometimes impressed into the wet plaster between the timbering.
BUILDING AND ARCHITECTURE
865
Stave churches
A different type of timber construction may be seen in the stave (mast) churches of
Norway. In these the roof was not supported on the walls; each part of the
structure was self-supporting. The building was based upon a skeleton framework
of vertical poles (the masts) which were slender tree trunks. The lower ends of
these were sunk into horizontal sills and the upper ends supported the roof. There
were cross beams near the top of the poles. The walls of such churches are stave
screens, self-contained wooden panels—rather like modern woven fence units—
which rested upon the timber sills and were attached to the poles but did not take
any weight or thrust. In advanced designs of churches of this type, there is an inner
ring of ‘masts’, so giving a nave and aisles to the interior.
Stave church design is based upon timber shipbuilding in which each section is
a self-sufficient unit. The interiors are tall and dark, bearing a resemblance to
inverted timber ships. They were constructed from about the eleventh century
until the Reformation, and during the nineteenth century about 500 churches
were extant. Their number is now greatly depleted and most survivors have been
extensively restored. A superb example is St Andrew’s Church of Borgund near
Laerdal; it was built c., 1150 and is about 15m (50ft) in height, erected in six
storeys. Another example near by is the church of the tiny community at Urnes.
Log construction
From the sixteenth century onwards timber building in Scandinavia followed the
more usual pattern of that in eastern Europe which was to build with whole logs
or logs split only down the centre, constructing with the curved side of the log
on the exterior of the building. Many examples of structures of all types, erected
over hundreds of years until the early twentieth century, may be seen in the
open-air museums where they have been re-erected to save them from total loss.
Of particular interest is the Norsk Folke museum at Bygdøy Park near Oslo, the

Aarhus Museum (Den Gamle By) in Denmark and the Village Museum in
Bucharest. The English equivalent, displaying timber-framed building, is the
Weald and Downland Museum at Singleton near Chichester.
The timber-trussed roof
This is an open interior roof system composed of a rigid construction of
timbers (the truss) which were pinned and tenoned together to provide a stable
combination which could resist all thrusts. Such roofs, constructed in Europe
chiefly between the eleventh and sixteenth centuries, represent the timber
equivalent of the stone vault (see pp. 874–6).
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The earliest designs were based on cruck construction, but gradually a more
sophisticated system was evolved empirically which would provide better
headroom and not obstruct the interior visibility. The medieval roof was generally
gabled at each end and, at least in northern Europe, was fairly steeply pitched. A
long baulk of timber extended along each side of the building on top of the walls:
this was the wall plate. Another such baulk was the ridge pole or ridge piece,
extending along the roof apex. Between these two were other beams running
parallel to them, fixed at intervals down the slope of the roof pitch: these were
purlins. Crossing these beams at right angles were the rafters which extended from
wall plate to ridge piece. At regular intervals were heavier rafters, called principal
rafters; in between were the thinner common rafters (see Figure 18.2).
The simplest and earliest form of timber-trussed roof was the tie beam design.
These tie beams were heavy baulks of timber spanning the interior at intervals
and pinned or tenoned into the wall plates in order to offset the outward thrust
of the roof upon the walls. Upon the beams were generally set one or two
vertical posts extending from them up to the ridge piece. If there is one central
post, it is called a king post, if two, they are queen posts. Horizontal beams set
higher up the roof are called collar beams. Connecting timbers were
incorporated to make the structure rigid. If straight they are called struts, if

curved, braces. A coupled roof is one constructed without tie or collar beams but
only struts or braces. It gives better internal visibility but is less strong. Vertical
posts extending from collar beam to the ridge piece are called crown posts.
In the late fourteenth century came the final and more complex design: the
hammerbeam roof. Hammer beams are like truncated tie beams. Extending at
wall plate level, they are supported from stone corbels embedded in the walls
by arch-braced wall posts. These shorter hammer beams gave better visibility
than the continuous tie beams. Vertical posts (hammer posts) stand upon or
are tenoned into the ends of the hammer beams and are attached to the collar
beams above where they join the purlins. Hammerbeam roofs are richly
decorated by carving, gilding and painting: many, especially the later
examples, for instance at Hampton Court Palace, are particularly ornate. The
finest hammerbeam roof is Hugh Herland’s earlier structure of 1394 covering
the interior of Westminster Hall in the Palace of Westminster in London.
BRICK AND TILE
Brickwork
Brick has been used as a building material for thousands of years. It has many
useful qualities: it is cheap and easy to make, the raw material is available
almost anywhere, it can be manufactured in different sizes, colours, qualities and
tex tures and it is durable, withstands the weather and is a good insulating
BUILDING AND ARCHITECTURE
867
material. It is also convenient to use in conjunction with other materials, partly
as bonding courses for added strength (as in Roman walling) and partly as a
colour contrast, a custom practised by many architects, for example, Sir
Christopher Wren, who used Portland stone as dressings for his brick buildings.
Figure 18.2: Timber-trussed roof with braced collar beams. Manor house, Solar, c.
1475–85.
Drawing by Doreen Yarwood.
PART FIVE: TECHNOLOGY AND SOCIETY

868
Early bricks, in areas of the world where the climate was sunny, were
sundried. Harder bricks were obtained by being exposed to heat from fire.
Such burnt bricks were being made in the Near East by 3000 BC. Later
references show such use in many parts of the world. The fifth century BC
Greek historian Herodotus tells us that such bricks were made to build the city
walls of Babylon. The Chinese used them in the third century BC to construct
parts of the Great Wall.
The Romans (as did the Etruscans before them) made extensive use of
brick in all forms of construction. Such bricks were sun-dried until the first
century BC, after which kiln-burnt bricks became more general. It was the
proud boast of the first Roman emperor, Augustus, that he found Romé a city
of bricks and left it a city of marble, but this only referred to the facing of the
buildings, which were still largely of brick construction underneath.
Roman builders used brick for arched openings, as bonding courses in
walling, for relieving arches in vaults (for example the Pantheon in Rome) and
for the colossal spans of the great basilicas and baths where they utilized brick
compartments in vaulting in conjunction with concrete. This wide use of
brickwork was extended further in the eastern area of Roman influence which
later became the Byzantine Empire. Roman building bricks were hard, large
and thin, resembling large tiles, and were laid with thick courses of mortar
between. Floor bricks were were also rectangular but smaller. Hypocaust pier
bricks were square.
After the collapse of the western part of the Roman Empire in the fifth
century AD, brickmaking died out in much of western Europe, especially in
Britain where it was not revived until the thirteenth century. Throughout the
Middle Ages, however, brick was a vitally important material along the coastal
regions of the North and Baltic Seas and bricks were being made from the early
Middle Ages along this coastal belt which extended for 1200 miles from Bruges
in Belgium to Novgorod in the USSR, the area made wealthy under the

administration of the Hanseatic League. Because it lacked other permanent
building materials brick was developed as a constructional and stylistic material
for all types of building from cathedrals and castles to guild halls and manor
houses. Brick is not an easy material to make into decorative forms, but a
simplified version of both Gothic and the later classical architecture of Europe
was created over the centuries by skilled craftsmen of the region and resulted in a
remarkable unity of style over so many countries in such a large area.
Bonding
In early brickwork, bricks were laid irregularly and, in walling, were often
mixed with flint and/or stone. As the work became more skilled bricks were
laid in a form of bonding, a uniform arrangement which ensures strength and
BUILDING AND ARCHITECTURE
869
is also decorative. Many different types of bonding have been developed over
the centuries. These vary from area to area but it has also been found that
some bonds are stronger than others and these are often more costly, so a
bond is chosen for a specific commission according to the quality and
appearance required whether it be an important building or a garden wall.
In England the most usual bond to be employed in medieval brickwork was
that termed English bond, which consists of alternate courses of headers and
stretchers. A header is a brick laid so that only its end appears on the wall face;
a stretcher is laid lengthwise to the face. This type of bond was in general use
in Tudor structures but, by the 1630s and 1640s, when brick building in
England was becoming much more common, partly due to the depletion of
timber stocks, Flemish bond gradually replaced it in popularity. This is laid
with alternate stretchers and headers on each course; an early example is Kew
Palace, built 1631.
The great age of English brick building was the century beginning in 1660
when high quality bricks were manufactured from a variety of clays. Limited
technical advances were made and the cost of brickmaking decreased, leading

to a growth of brick building. Unfortunately in the later eighteenth century,
this situation attracted the attention of government: a brick tax was imposed in
1784 and soon was twice increased, resulting in a serious curtailment of brick
building of smaller structures in rural areas.
The brick tax was repealed in 1850. Contemporaneously the building needs
following the tremendous population explosion and those of urbanization
stemming from the Industrial Revolution led to an immense acceleration in
brickmaking. Partly this boom was to serve the housing building industry but
it was also for the construction of railway viaducts, tunnels, cuttings and
stations, as well as factories and warehouses. Technical advances and
improvements in brickmaking rendered the material the cheapest and the most
ready to hand. Bricks were made for all purposes in different qualities by
different processes. A wide range of colours was available and Victorian
architects readily adopted the fashion for polychromy in their designs.
Brickmaking
Three chief stages of production are involved in the making of bricks from clay
by heating or burning them. This has been so since the earliest bricks were
made though, with the passage of time, the methods for carrying out the
processes have become more complex and mechanized. The raw material has
to be dug out of the ground, it then needs to be prepared and moulded into
shape and, afterwards, burnt.
After the clay has been dug, it has to be puddled. This is a preparation
process which includes removing pebbles and extraneous matter from the clay,
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then mixing and squeezing it with the addition of water and sand to give an
even consistency. Often more than one clay is used in the mix so that the
properties of one will counteract or improve the properties of others. Before the
seventeenth century puddling was done by men treading the substance
barefoot. After this the pug-mill gradually replaced the human labour. The mill

was cylindrical; it contained a central shaft with blades attached which acted in
the same manner as a butter churn. Early mills were powered by a horse or
donkey on a treadmill (see Chapter 4). Later the pug-mill contained rotating
wheels and, according to date, was powered by water, steam or electricity.
The early way to mould the bricks into the shape required was by human
hands. During the Middle Ages moulds were used and later these were made
with detachable base so comprising a stock mould and stock board.
Clamps were constructed in early times for brick burning. The clamp
consisted of stacked bricks intermingled with brushwood which was the fuel.
The clamp was lit from the exterior and allowed to burn itself out. This
method caused bricks to be unevenly fired, the ones on the interior of the
clamp being burnt more than those on the exterior and so, having lost more
water, they were smaller and darker in colour. It was this which gave to
fifteenth- and sixteenth-century brickwork an interesting variety of shape and
tone. On a site with a suitable clay sub-soil, the whole brickmaking process
might at this time be carried out where the building was to be constructed.
Gradually the kiln system superseded the clamps and, after about 1700, coal
and coke replaced wood as fuel.
At this time advances in brickmaking slowly took place but it was the
midnineteenth century before these resulted in mass-production systems. Then
many hand processes became mechanized, also delay in drying bricks before
firing was eliminated by mechanical drying. The introduction of the Hoffman
Kiln of 1858 was a great advance as its multi-chamber system enabled the
firing process to operate continuously with brick stacks at different stages of
firing or cooling instead of waiting for a fortnight for each setting of bricks to
dry as before. The development of the Fletton process in the 1890s was a
further great advance. Fletton is an area near Peterborough in Cambridgeshire,
where a certain shale-clay is found in quantity. This material has a low water
content which makes it suitable to be pressed into a brick mould without
previous drying. Finally, brickmaking machinery replaced remaining hand

processes for making bricks about 1885, vastly increasing the speed at which
bricks could be turned out.
Tiles
Also fired in a kiln, tiles are less porous, harder and smoother than bricks.
They are traditionally used for roofing and also for wall and floor covering,
BUILDING AND ARCHITECTURE
871
where they might be decorated and glazed. In England, in the later
seventeenth century, the craft of tile-hanging was developed. Also known as
weather-tiling because of its use as protection from rain and snow, it is
ornamental, too, and varied designs were adopted. The tiles were hung on
wood battens plugged into the walls or were pegged or nailed into mortar
courses. In general, tile-hanging was practised more in the south of the country
and slate-hanging in the north.
Another use for tiles was found in the second half of the eighteenth century;
these were called brick tiles, alternatively, mathematical or weather tiles. These
were generally made to the same linear dimensions as bricks and their purpose
was to be applied to walls as a tiled skin to cover the original material of the
wall behind which might be timber and plaster. An older, simpler building
might thus acquire the appearance of a more fashionable brick one. These tiles
were employed by many of the fashionable architects of the day and especially
in the south-east of England; the Royal Crescent on Brighton sea-front (c.
1800) is a notable example where black glazed tiles have been used.
Terracotta and Coade stone
Terracotta is also a fired earthenware material which is harder and less porous
than brick. It is used chiefly for decoration on buildings where it is moulded
into ornamental or sculptural forms. Its use was introduced into England in
the early sixteenth century by Italian craftsmen as can be seen, for example, in
the roundels on the gateways of Hampton Court Palace by Giovanni da
Maiano. Architects of the nineteenth-century Gothic Revival utilized terracotta

extensively as a decorative medium. A well-known instance of this is Alfred
Waterhouse’s Natural History Museum in London (1873–9), where the
architect faced the façade in two shades of the material—buff and grey—and
decorated it with a wealth of animal and plant sculptures.
The mix for terracotta includes grog, that is, previously fired earthenware
ground to a powder and this was also the basis for Coade stone, an extremely
hard and durable material which was employed as an artificial stone by most
of the leading architects of the day, including Robert Adam, Sir William
Chambers, John Nash and Sir John Soane.
The manufactory of Coade stone was established by Mr and Mrs Coade in
1769 in Lambeth and it was run by their daughter Eleanor. The formula for
the material was kept very secret but modern analysis has shown it to be a
combination of china clay, grog from pulverized stoneware and various fluxes.
It was a particulary stable, smooth substance eminently suited to making
larger-thanlife-size statuary and ornament and it has, in many instances,
endured city atmospheric pollution better than actual stone, This may be seen,
among other famous buildings, at the Royal Naval College in Greenwich,