Cottage Building in Cob Pise Chalk and Clay Part 6

_Rendering._--"For the rough-weather sides of cob buildings I have found cement and sand, finished with a rough surface, satisfactory, and far more durable than ordinary lime and gravel rough cast. For interior cob walls, laths are not necessary. The old plastering was frequently laid on too thick. Of late years I have used with excellent results granite silicon plaster for ceilings and walls. This requires no hair, and is easily applied."

_The Cob Tradition._--"Cob-making was, like many other local trades, carried on in some families from generation to generation and developed by them into an art, but apart from these specialists, practically every village mason and his labourers built as much with cob as they did with stone. There are men still left in various parts of the county who have made cob, and it would, in my opinion, be of advantage if demonstrations could be given by them to discharged sailors and soldiers who are anxious to take up work on the land."

_Training of ex-Soldiers._--"In cob-building, as in many other arts and crafts, a little showing is of far greater help to the novice than any amount of text-book instruction. The knowledge and experience that these men would gain from being shown, and better still, a.s.sisting an expert in making cob, would be of material advantage in the development of the county scheme promoted by the Central Land a.s.sociation for the establishment of ex-Service men on the land. They could try their 'prentice hands on walls, tool-sheds, cart linhays, etc., for their own use, and some no doubt would develop into expert builders capable of constructing walls for dwelling-houses from approved plans."

_1819 Conditions Returned._--"The depletion of our home-grown timber supply and the prohibitive cost of practically all building material has in effect brought about the conditions that led our forefathers to utilise suitable material that lay nearest to hand, and unless some endeavour is made to follow their methods and profit by their example, it will be impossible to provide sufficient buildings for the necessary equipment of the allotments and small holdings, let alone housing accommodation for the workers on the land."

[Headnote: A Champion of Cob]

There is probably no one who knows more about cob than does Mr.

Fulford--certainly no one who has done more to promote the revival of cob-building both by precept and example.

Cob is the traditional material of his native place, he has, as it were, been brought up on cob--he is familiar with both the ancient history and the modern practice of cob-building, and in short, he "knows."

When a revivalist has knowledge as well as enthusiasm, the grounds of his faith are usually worth serious attention.

II

_PISe DE TERRE_

-- I. GENERAL

_What it is._--"Pise de terre" is merely the French for rammed earth, and rammed earth is an exceedingly good material for the building of walls.

The odd thing is that its very obvious merits should have secured it such small attention.

It is no new-fangled war-time invention brought forth by our present necessity, but a very ancient system well proved by centuries of trial.

_History._--Pliny gives an excellent account of Pise-building in his _Natural History_, and Monsieur Gorffon, who published a treatise on this method of construction in 1772, states that it was first introduced into France by the Romans.

The following extracts from an old book based on a French original will serve well as an introduction to the study of Pise-building:

_Capabilities._--"An account of a method of building strong and durable houses, with no other materials than earth; which has been practised for ages in the province of Lyons, though little known in the rest of France, or in any other part of Europe. It appeared to be attended with so many advantages, that many gentlemen in this country who employ their leisure in the study of rural economy were induced to make a trial of its efficiency; and the result of their experiments has been of such a nature as to make them desire, by all possible means, to extend the knowledge and practice of so beneficial an art.

"The possibility of raising the walls of houses two or even three stories high, with earth only, which will sustain floors loaded with the heaviest weights, and of building the largest manufactories in this manner, may astonish every one who has not been an eye-witness of such things."

_Of Pise and its Origin._--"Pise is a very simple manual operation; it is merely by compressing earth in moulds or cases, that we may arrive at building houses of any size or height."

_Locale._--"This art, though at present confined to the single province of the Lyonese in France, was known and practised at a very early period of antiquity. The Abbe Rozier, in his _Journal de Physique_, says that he has discovered some traces of it (Pise) in Catalonia; so that Spain, like France, has a single province in which this ancient manner of building has been preserved. The art, however, well deserves to be introduced into more general use. The cheapness of the materials which it requires, and the great saving of time and labour which it admits of, must recommend it in all places and on all occasions, but the French author says that it will be found particularly useful in hilly countries, where carriage is difficult, and sometimes impracticable; and for farm buildings, which, as they must be made of considerable extent, are usually very expensive, without yielding any return."

[Headnote: Method of Building]

-- II. METHOD OF BUILDING

There is an exhaustive article on Pise in Vol. XXVII of _The Cyclopaedia or Universal Dictionary of Arts, Sciences, and Literature_, published in 1819. The writer, Abraham Rees, D.D., F.R.S., F.L.S., draws chiefly on French authorities and his directions are most detailed and precise.

[Ill.u.s.tration: PISe.

_Implements for Pise or Rammed Earth Buildings_ +Pise Plant and Implements.+ (Reproduced from an old Encyclopaedia.)]

_Definition._--He introduces his subject thus:

"Pise-building, in Rural Economy, the name of a method of building with loamy or other earthy matters, which has long been practised with great success, and in a very cheap manner, in some departments of France, and which is now had recourse to with similar advantage in some parts of this country. It has been described, delineated, and recommended by Mr.

H. Holland in the first volume of _Communications to the Board of Agriculture_, and is to be managed somewhat in the manner directed below."

At great length and with immense detail, the plant, the preliminaries, and the process are each severally described.

The pith of the matter is sufficiently given by the following extracts:

_Shuttering._--"For the construction of the mould, take several planks, each 10 ft. long, of light wood, in order that the mould may be easy to handle; deal is the best as being least liable to warp. To prevent which the boards should be straight, sound, well seasoned, and with as few knots as possible. Let them be ploughed and tongued, and planed on both sides. Of these planks, fastened together with four strong ledges on each side, the mould must be made, 2 ft. 9 in. in height; and two handles should be fixed to each side.

"All the boards and ledges here mentioned must be, after they are planed, something more than 1 in. thick."

_Rammer._--"The instrument with which the earth is rammed into the mould is a tool of the greatest consequence, on which the firmness and durability, in short the perfection, of the work depends. It is called a pisoir, or rammer; and though it may appear very easy to make it, more difficulty will be found in the execution than is at first apprehended.

A better idea of its construction may be formed by examining the Plate, in which it is delineated, than any words can convey. It should be made of hard wood, either ash, oak, beech, walnut, etc., or what is preferable, the roots of either of them."

_Method of Working._--"Pise contains all the best principles of masonry, together with some rules peculiar to itself, which are now to be explained.

"To begin with the foundation; this may be made of any kind of masonry that is durable, and should be raised to the height of 2 ft. above the ground; which is necessary to secure the walls from the moisture of the earth, and the splas.h.i.+ng of the rain, which will drop from the eaves of the roof.[4] When these foundation walls are made level, and 18 in.

thick, mark upon them the distance at which the joists are to be set, for receiving the moulds; those distances should be 3 ft. each from centre to centre. Each side of the mould being 10 ft. long, will divide into three lengths of 3 ft. each, and leave 6 in. at each end, which serve to lengthen the mould at the angles of the house and are useful for many other purposes. After having set the joists in their places, the masonry must be raised between them 6 in. higher, that is, to a level with the joists; there will, therefore, altogether be a base of 2 ft., which in most cases will be found more than sufficient to prevent the rain, frost, snow, or damp from injuring the walls. Raise the mould immediately on this new masonry, placing it over one of the angles of the wall.

[Footnote 4: The introduction of a damp-course and the provision of gutters at the eaves greatly reduce the function of the masonry base in modern work.]

[Headnote: The Ramming]

"A workman should be placed in each of the three divisions of the mould, the best workman being placed at the angle. He is to direct the work of the other two, and by occasionally applying a plumb-rule, to take care that the mould does not swerve from its upright position. The labourers who dig and prepare the earth must give it in small quant.i.ties to the workmen in the mould, who, after having spread it with their feet, begin to compress it with the rammer. They must only receive at a time so much as will cover the bottom of the mould to the thickness of 3 or 4 in. The first strokes of the rammer should be given close to the sides of the mould, but they must be afterwards applied to every other part of the surface; the men should then cross their strokes, so that the earth may be compressed in every direction. Those who stand next to one another in the mould should regulate their strokes so as to beat at the same time under the cord, because that part cannot be got at without difficulty, and must be struck obliquely; with this precaution, the whole will be equally compressed. The man at the angle of the wall should beat carefully against the head of the mould.

"Care must be taken that no fresh earth is received into the mould till the first layer is well beaten, which may be ascertained by striking it with a rammer; the stroke should leave hardly any print on the place.

They must proceed in this manner to ram in layer after layer, till the whole mould is full. When this is done, the machine may be taken to pieces, and the earth which is contained will remain firm and upright, about 9 ft. in length and 2 ft. in height. The mould may then be replaced for another length, including 1 in. of that which has first been completed.

"The first course being thus completed, we proceed to the second; and here it must be observed that in each successive course we must proceed in a direction contrary to that of the preceding. It may easily be conceived, that with this precaution the joints of the several lengths will be inclined in opposite directions, which will contribute very much to the firmness of the work. There is no reason to fear overcharging the first course with the second, though but just laid; for three courses may be laid without danger in one day.

"This description of the first two courses is equally applicable to all the others, and will enable any person to build a house, with no other materials than earth, of whatever height and extent he pleases.

"With respect to the gables, they may be made without any difficulty, by merely making their inclination in the mould and working the earth accordingly."

-- III. THE THEORY AND SCIENCE OF PISe