The use of sun-dried bricks in this country, is, for no very apparent
reason, almost entirely restricted to East Anglia. There it has been
used for generations with entirely satisfactory results.
Mr. Skipper of Norwich writes of the material as follows:
* * *
"Who, travelling from Norfolk to London, whether by the Ipswich or
Cambridge line, has not noticed the numerous colour-washed or black
(tarred) cottage, farmhouse and agricultural buildings scattered
practically all along the countryside? Some of these are of studwork and
plaster, some of wattle and daub, but many are built of clay made up
into lumps, sun-dried, and built into the walls with a soft clay-mixture
as mortar. No lime _need_ be used, though sometimes it is mixed with the
clay mortar. The preparation, digging, exposure and mixing with short
straw are similar to the Devonshire 'cob' work, but in these parts the
worked clay is thrown into moulds, and lumps are formed of, say, 18 in.
by 12 in. by 6 in., or 18 in. by 9 in. by 6 in. for large sizes, and for
inside walling or backing to brick-faced walls, 18 in. by 6 in. by 6 in.
The walls, naturally, are rough in texture and the joints are generally
stopped up and besmeared with a thin coating or almost a wash of clay.
This coating sometimes has lime mixed with it, but it is not necessary.
This is all that is needed to complete the walling, and there is a
building--a malting, that any one can see at Tivetshall Station on the
Ipswich line, about 200 ft. long, 45 ft. or 50 ft. wide and three floors
high, built of lumps 18 in. by 12 in. by 6 in.--that has stood the
weather and weight of its roof for forty years built in this way; 12 in.
is the thickness of its walls. A further stage in finish is to give the
walls two or three coats of coal tar, but it is not essential, though
desirable where stock are kept, as cattle are rather fond of licking the
clay, and they do not use their horns much when walls are tarred. The
highest finish in this work is to cast sand on the last coating of tar
before it is quite dry, and then to colour or whitewash on this. This
accounts for the variety of colourings seen in these buildings, some
even of a kind of pink or red; while some yellow or buff, beside the
white and the black or tarred buildings, and all huddled together or
standing apart, whether covered with thatch or red pan or flat tiles,
look remarkably in harmony with their surroundings. These lump walls
are, of course, built on a base of brickwork, about 18 in. or 2 ft.
high, to keep them free from damp. This kind of walling can be built for
_at least_ 15 per cent. or 20 per cent. cheaper than ordinary 9 in.
brickwork. Thin as these walls are compared with those of 'cob' houses,
they are noted for being warm in winter and cool in summer. When
suitable clay is procurable a local builder almost invariably uses clay
lumps when building a house for himself, though to gratify a whim
perhaps, he will case the outside walls--especially the front next the
street or road--with brickwork. But clay lumps he carefully reserves for
inside walls and weight-carrying linings to the outside walls, bonding
the two together very much in the same way as two 4-1/2 in. 'cavity
walls' are bonded. I am not suggesting that this walling is as
interesting artistically as 'cob,' but I do suggest it is a practical,
sensible and _dry_ walling, and if properly done it will 'last for
ever,' as a local builder repeatedly said to me when speaking of it.
One can easily see why the cost is light--the sun and the winds do the
drying in the spring months, and no coals are required, and also the
clay is often found on the building site, hence no cartage. Actual
building work naturally goes quickly, as the lumps are large. There is
another important point to notice. One may see a building complete with
its roof on and occupied by its tenant while still awaiting an outside
casing of brickwork to be built round it, either with a view to greater
protection or for the mere vanity of the owner, for while thus left
unprotected the lump walls take no harm from even winter exposure. Now
to be quite practical in these extremely practical days, I venture to
suggest that the use of clay lumps at least for inside walls and
linings of outside walls would be an immense boon to the numerous
cottage-building schemes now being projected. We must not forget that
comparatively few bricks will be available this year, while the cottages
are wanted at once. Can these few bricks be better used than by forming
foundations and chimneys for the clay-lump walls of these cottages? I
think not. The cottages could, of course, be occupied in the late summer
or autumn of this year, and next year when bricks will be more plentiful
perhaps the brick casings could be added, if brickwork _must_ complete
them. I make this strictly utilitarian suggestion solely to meet a very
urgent and deep national need. Personally, I prefer the sight of a
cottage built and finished in the old-established method of the
locality. Unskilled labour only is required, working under intelligent
supervision, hence immediate employment for a great number of men would
be provided."
[Headnote: Use for Unskilled Labour]
* * *
[Illustration:
+Once Corn Hall, now Council School.+
Built about a hundred years ago. Still in sound condition
and quite dry.]
[Illustration:
+A Row of Clay-lump Cottages.+
The front has been plastered and panelled out. In the upper part
of the stable building, seen in the foreground, the clay-lumps
are shown exposed.]
[Illustration:
+Engineering Workshops.+
Built twenty years ago. The walls are thoroughly sound, despite
constant vibration, and are perfectly dry, except the brick face,
which was added for effect.]
The use of sun-dried bricks for the interior partitions of cob and pise
cottages is worth consideration, as the nature of these materials
demands a thickness of wall which is too wasteful of space to be
acceptable in mere partitioning.
Of the strength of clay-lump walls, there is no question. It was
recently necessary to cut a new doorway in the old clay-lump wall of a
large traction-engine garage, and the blocks removed were thrown into a
heap upon the ground.
The clay happened to be needed for other purposes, for which it had
first to be broken up.
Ordinary hammers proved entirely ineffective, and it was not until heavy
sledges were used that the lumps could be smashed.
The tractor-house in question is a large building some 25 ft. by 100
ft., carrying a heavy roof and constantly subjected to vibration by the
coming and going of the tractors.
The walls are only 12 in. thick, without piers or reinforcements of any
kind, and yet the whole building, which is 26 ft, high at the gables, is
as perfect to-day as when first erected some twenty years ago.
In the same town as this tractor-house, East Harling in Norfolk, is a
council school built of clay lump (converted from the old Corn Hall),
apparently not a pin the worse for a century of hard wear.
Near by there are a number of private houses built of the same material,
some of them reputed to be upwards of 200 years old and certain of them
having considerable architectural merit.
[Headnote: "Substantial and Cool"]
(_Extract from "The Farmers' Handbook," issued by the Department of
Agriculture, New South Wales, 1911_)
+"Adobe," or Sun-dried Bricks+
"As their name implies, these buildings are constructed of sun-dried,
but unburnt bricks. For buildings of this character, material like clay,
which is unsuitable for pise-work, can be used. The bricks are made in a
wooden mould, and are 16 in. long, 8 in. wide, and 6 in. thick. A man
can mould about 100 per day. They are laid in a similar manner to other
bricks, the mortar used being wet loam, or even the material of which
the bricks are made. The cost of making and laying is estimated at about
15s. per 100. Buildings constructed of these bricks are substantial and
cool, and very similar in character to pise buildings.
"A school-house built of these bricks eighteen years ago by Mr. Nixon,
of Reefton, is still in an excellent state of preservation; in fact,
little, if any, the worse for wear, despite the fact that walls are
unprotected by verandahs or overhanging eaves. During its existence it
has had, first one coat of oil-paint, and later a coat of coloured
limewash."
* * *
"Clay lump," then, is one of the many good old building methods that
needs no proving, but only revival and perhaps improvement.