“Proper earth is found at the bottom of the slopes of low lands that are cultivated, because every year the rain brings down the fat or good earth. It is frequently found on the banks of the river, but above all, it is found at the foot of hills, and on all cultivated lands which have much slope. In digging trenches and cellars for building, it generally happens that what comes out of them is fit for the purpose.”
ON THE MIXTURE OF EARTHS
Soil Blending.—“As it may sometimes happen that earth of a proper quality is not to be found on the spot where it is intended to build, it becomes of importance to attend to the method of mixing earths; for though the earth which is near at hand may not of itself be proper, it is very probable that it may be rendered so by the mixture of a small quantity of another earth fetched from a distance. The principle on which a mixture must be made is very simple; strong earths must be tempered with light; those in which clay predominates, with others that are composed more of chalk and sand; and those of a rich, glutinous substance, with others of a poor and barren nature. The degree in which these qualities of the earths prevail must determine the proportions of the mixture; which it is impossible here to point out for every particular case, but which may be learnt by a little practice. Some easy methods will be described, by which any one may make a trial of the qualities of his earth.
“It will not be amiss to mix with the earth some small pebbles, gravel, rubbish of mortar, or in short any small mineral substances; but none of the animal or vegetable kind must be admitted.5 Such hard substances bind the earth firmly between them, and being pressed and pressing in all directions, contribute very much to the solidity of the whole; so that well-worked earth, in which there is a mixture of gravel, becomes so hard at the end of two years that a chisel must be used to break it, as if it was freestone.”
Experiments
EXPERIMENTS TO ASCERTAIN THE QUALITIES OF ANY EARTH
Trial by Experiment.—“Take a small wooden tub or pail, without a bottom, dig a hole in the ground of a court or garden, and at the bottom of that hole fix a piece of stone, flat and level; place your tub upon the stone, fill around it the earth that has been dug out to make the hole, and ram it well, that the tub may be enclosed, to prevent its bursting. Then ram into the tub the earth you mean to try; putting in, at each time, about the thickness of three or four fingers’ breadths: when this is well rammed, add as much more, and ram it in the same manner, and so the third and fourth, etc., till the earth is raised above the brim. This superfluous earth must be scraped off extremely smooth, and rendered as even as the under-part will be, which lies on the stone. Loosen with a spade the earth around the tub, and you will then be able to take it out, and with it the compressed earth that it contains; then turn the tub upside down, and if it is wider at the top than at the bottom, as such vessels usually are, the pisé will easily come out, but if it should happen to stick, let it dry in the air about twenty-four hours, and you will then find that the earth is loose enough to fall out of itself. You must be careful to cover this lump of pisé with a little board; for though a shower of rain, falling in an oblique direction, will not injure it, yet it may be a little damaged if the rain falls perpendicularly, and especially if it remains upon it. Leave the lump exposed to the air, only covered with a board or flat stone, and if it continues without cracking or crumbling, and increases daily in density and compactness as its natural moisture decreases, you may be sure that the earth is fit for building. But you must remember that it is necessary that the earth employed should be taken from a little below the surface of the ground, in order that it may be neither too dry nor too wet; it must be observed also that if the earth is not well pressed around the outside of the tub before it is filled, though the hoops were of iron, they would burst, so great is the pressure of the beaten earth against the mould, of whatever size it may be.”
The Earth-ball Test—An Experiment which may be made at any time.—“Every person in walking on his ground may make little balls of earth and press them as tight as he can between his hands. If he brings them home and puts marks on them, he will by that means know the quality of every piece of land, and also be a judge of the mixture it will be necessary to make.”
Preparation of the Earth
ON THE PREPARATION OF THE EARTH FOR BUILDING
Soil Preparation.—“All the operations of this art are very simple and easy; there is nothing to be done but to dig up the earth with a pickaxe, break the clods with a shovel, so as to divide it well, and then lay it in a heap, which is very necessary, because as the labourers throw it on that heap, the lumps of earth and large stones roll to the bottom, where another man may break them or draw them away with a rake. I must observe that there should be an interval of about an inch and a quarter between the teeth of the rake, that the stones and pebbles of the size of a walnut, or something more, may escape, and that it may draw off only the largest. If the earth that has been dug has not the proper quality, which is seldom the case, and it is necessary to fetch some better from a distance, then the mixture must be made in this manner: one man must throw one shovelful of the best sort, while the others throw five or six of the inferior sort on the heap, and so more or less according to the proportions which have been previously ascertained.”
Rain.—“No more earth should be prepared than the men can work in one day, or a little more, that they may not be in want; but if rain is expected, you must have at hand either planks, mats, or old cloths to lay over the heap of earth, so that the rain may not wet it; and then as soon as the rain is over, the men may resume their work, which, without this precaution, must be delayed; for it must be remembered that the earth cannot be used when it is either too dry or too wet, and therefore if the rain should wet it after it has been prepared, the men will be obliged to wait till it has recovered its proper consistency—a delay which would be equally disadvantageous to them and their employer. When the earth has been soaked by rain, instead of suffering compression, it becomes mud in the mould; even though it be but a little too moist, it cannot be worked; it swells under the blows of the rammer, and a stroke in one place makes it rise in another. When this is the case, it is better to stop the work, for the men find so much difficulty that it is not worth while to proceed. But there is not the same necessity of discontinuing the work when the earth is too dry, for it is easy to give it the necessary degree of moisture; in such a case it should be sprinkled with a watering-pot, and afterwards well mixed up together; it will then be fit for use.”
Organic Matter.—“It has already been observed that no vegetable substances should be left in the earth; therefore in digging, as well as in laying the earth in a heap, great care must be taken to pick out every bit of root, great and small, all sprigs and herbs, all bits of hay and straw, chips or shavings of woods, and in general everything that can rot or suffer a change in the earth.”
ON THE BOND TIMBER TO BE USED IN BUILDINGS OF PISÉ
Corners.—“To make good walls, it is not sufficient that the earth be well beaten, we must also learn to unite them well together. Here the binders cost very little; they consist only of thin pieces of wood, a few cramps and nails, and these are sufficient to give the greatest stability to buildings of pisé.”
Having gone on to explain that the angles of the building are formed by the successive courses alternately crossing one another on the corner like the alternating “long and short” quoins in a stone building, our authority proceeds to describe how rough boards are laid between the courses of pisé so as to cross at the corner and so, entirely encased in tightly compressed earth, they form effective ties.
“This board must be rough, as the sawyers have left it, 5 or 6 ft. long, something less than 1 in. thick, and in breadth about 8, 9 or 10 in., so that there may remain on each side 4 or 5 in. of earth, if the wall is 18 in. thick; by this means the board will be entirely concealed in the body of the wall. When thus placed neither the air nor damp can reach it, and of course there is no danger of its rotting. This has been often proved by experience, as in taking down old houses of pisé such boards have always been found perfectlysound, and many that had not even lost the colour of new wood. It is easy to conceive how much this board, from the pressure of the work raised above it, will help to bind together the two lengths of wall and to strengthen the angle.”
Bonders.—“It is useful (particularly when the earth is not of a very good quality) to put ends of planks into the pisé after it has been rammed about half the height of the mould. These ends of planks should only be 10 or 11 in. long, to leave as before a few inches of earth on each side of the wall, if it is 18 in. thick; they should be laid crosswise (as the plank before mentioned is laid lengthwise) over the whole course, at the distance of about 2 ft. from one another, and will serve to equalise the pressure of the upper parts of the works on the lower course of the pisé.
“The boards above mentioned need only be placed at the angles of the exterior wall, and in those parts where the courses of the partition walls join to those of the exterior wall, the same directions that have here been given for the second course must be observed at each succeeding course, up to the roof. By these means the reader will perceive that an innumerable quantity of holders or bondings will be formed, which sometimes draw to the right, sometimes to the left of the angles, and which powerfully unite the front walls with those of the partitions; the several parts deriving mutual support from one another, and the whole being rendered compact and solid.”
The Strength of Pisé
Strength.—“Hence these houses, made of earth alone, are able to resist the violence of the highest winds, storms and tempests. The height that is intended to be given to each story being known, boards of 3 or 4 ft. in length should be placed beforehand in the pisé, in those places where the beams are to be fixed, and as soon as the mould no longer occupies that place, the beams may be laid on, though the pisé be fresh made; little slips of wood, or boards, may be introduced under them, in order to fix them level. The beams thus fixed for each story, the pisé may be continued as high as the place on which you intend to erect the roof.”
ON THE TIME AND LABOUR NECESSARY IN BUILDING A CERTAIN QUANTITY OF PISÉ
Speed of Building.—“Besides the advantages of strength and cheapness, this method of building possesses that of speed in the execution. That the reader may know the time that is required for building a house, or an enclosure, he need only be told that a mason used to the work can, with the help of his labourer, when the earth lies near, build in one day 6 ft. square of the pisé.”
Rendering.—“To prepare the walls for plastering, indent them with the point of the hammer, or hatchet, without being afraid of spoiling the surface left by the mould; all those little dents must be made as close as possible to each other, and cut in from top to bottom, so that every hole may have a little rest in the inferior part, which will serve to retain and support the plaster.
“If you happen to lay the plaster over them before the dampness is entirely gone, you must expect that the sweat of the walls will cast off the plaster.”
The wall surface having been duly hammer-chipped, the work must be scoured with a stiff brush to remove all loose earth and dust, and to finally prepare it for rough-casting. Rough-cast consists of a small quantity of mortar, diluted with water in a tub, to which a trowel of pure lime is added, so as to make it about the thickness of cream.
One workman and his labourers are sufficient; the workman on the scaffold sprinkles with a brush the wall he has indented, swept, and prepared; after that he dips another brush, made of bits of reed, box, etc., into the tub which contains the rough-cast, and throws with this brush the rough-cast against the wall.
“Rough-cast, which is attended with so little trouble and expense, is notwithstanding the best cover that can be made for pisé walls, and for all other constructions; it contributes to preserve the buildings. It is the peculiar advantage of these buildings that all the materials they require are cheap, and all the workmanship simple and easy.”
Local Testimony.—At the end of the article just summarised, an instructive letter from a former rector of St. John’s, La Rochelle, is quoted:
“Sir,—
“My having been an inhabitant for some time of the town of Montbrison, capital of the Forets, enables me to give you some information concerning the mode of building houses with earth, etc.
A Pisé Church
A Pisé Church.—“The church was the most remarkable in this style of building; it is about 80 ft. long, 40 ft. broad, and 50 ft. high; the walls built in pisé, 18 in. thick, and crépé, or rough-cast on the outside, with lime and sand. Soon after my arrival, the church, by some accident, was destroyed by fire, and remained unroofed for about a twelvemonth, exposed to rains and frost. As it was suspected that the walls had sustained much damage, either by fire or the inclemency of the season, and might fall down, it was determined to throw them down partially, and leave only the lower parts standing; but even this was not done without much difficulty, such was the firmness and hardness these walls had acquired, the church having stood above eighty years; and all the repairs required were only to give it on the outside, every twelve or fifteen years, a new coating of rough-cast.
“A house for a single family is generally finished in about a fortnight. The following is the method I have seen them practise.”
Building Procedure.—“The earth is pounded as much as possible, in order to crumble any stones therein; clay is added thereto in a small quantity, about one-eighth part. It is all beaten and mixed up together by repeated blows with a mallet about 10 in. broad, and 10 or 15 in. long, and 2 in. thick. The earth being thus prepared, and slightly wetted, the foundation of the house is dug for; this is laid with stone, and when it is about 1 ft. high above the surface of the ground, planks are arranged on each side, which are filled with earth intended for the wall; this is called Pisé in the dialect of the country. It is strongly beaten; and this method is continued successively all round the building. The walls have more or less thickness according to the fancy of the owner; I have seen them 6 in. and 18 in. thick. If several stories are intended in such erections, they do not fail to place beams to support the floors before they build higher. Of such buildings I never saw any consisting of more than three floors at most; generally they have but two. When the building is thus finished, it is left for some months to dry; then such as wish to make the building more solid and durable, give it a rough-cast coating on the outside with lime and sand. This is what I have observed during a residence of three years in the town of Montbrison. I should be happy if this detail should afford the slightest information to the generous nation which has received us with so much goodness.
“I am, etc.,
“Jaucour.”
The Virtues of Pisé.—“Such is the method of building which has been practised in the Lyonnese for many centuries. Houses so built are strong, healthy, and very cheap, they will last a great length of time, for the French author says he had pulled down some of them which, from the title-deeds in the possession of the proprietors, appeared to be 165 years old, though they had been ill kept in repair. The rich traders of Lyons have no other way of building their country-houses. An outside covering of painting in fresco, which is attended with very little expense, conceals from the eye of the spectator the nature of the building, and is a handsome ornament to the house. That method of painting has more freshness and brilliancy than any other, because water does not impair the colours. No size, oil, or expense is required, manual labour is almost all it costs, either to the rich or poor. Any person may make his house look as splendid as he pleases, for a few pence laid out in red or yellow ochre, or in other mineral colours.
“Strangers who have sailed upon the Rhône probably never suspected that those beautiful houses, which they saw rising on the hills around them, were built of nothing but earth, nay, many persons have dwelt for a considerable time in such houses without ever being aware of their singular construction. Farmers in that country generally have them simply white-washed, but others, who have a greater taste for ornament, add pilasters, window-cases, panels, and decorations of various kinds.
“There is every reason for introducing this method of building into all parts of the kingdom; whether we consider the honour of the nation as concerned in the neatness of its villages, the great saving of wood which it will occasion, and the consequent security from fire, or the health of the inhabitants, to which it will greatly contribute, as such houses are never liable to the extremes of heat or cold. It is attended with many other circumstances that are advantageous to the State as well as to individuals. It saves both time and labour in building, and the houses may be inhabited almost immediately after they are finished; for which latter purpose, the holes made for the joists should not be closed up directly, as the air, if suffered to circulate through them, will dry the walls more speedily.”
Indian and Colonial Practice
§ IV. Indian and Colonial Practice
A Manual on Earthwork, edited by Colonel Maclagan, R.E., gives much interesting information as to Pisé-building and a number of valuable hints:
Shutter-ties.—“Cross pieces, as the work proceeds, become so firmly embedded in the wall, that there is great difficulty in extracting them, to remedy which iron bars have been substituted. Even these thin iron bars become so tightly jammed when surrounded by the compact pisé earth, that much labour and risk of injury to the work is incurred in extricating them, and the expedient of setting them in a bed of sand has been successfully resorted to. They are then drawn out with care, the sand also is removed, and the holes which they leave are subsequently filled with the same earth of which the wall is made, and rammed hard.
“The heads of the opposite uprights are held together by ropes, but in practice in this country6 it has been found that, under the immense pressure exerted upon the plank sides by the earth firmly rammed in the interior, the ropes are so liable to stretch, and to break, that it is advisable to use iron rods or bars in this position also. When ropes are used, the distance between the side planks is measured by gauge rods, and the ropes tightened when requisite to preserve the proper breadth of wall. The use of iron connecting rods renders this unnecessary.”
Soil.—“Soil of a medium quality, that is neither very stiff nor very sandy, is considered best adapted for pisé. It may be said that that which would make good bricks will answer well for this description of work.
“When the earth is very dry, a sprinkling of water will be necessary.”
Foundations.—“It is usual to begin the work upon a foundation of brick or masonry; but there seems to be no reason why the pisé might not be used from the commencement, even for foundations under ground; being carefully guarded from all chance of injury by running water.”
The Building.—“The casing being prepared and erected, and the upper surface of the old work, when above the first stage, being sprinkled with water, the earth, well mixed and slightly moistened, is thrown in, and spread in thin layers of 4 or 5 in. These should, when rammed, be reduced to one-half their original thickness. The rammers should be of hard wood and very smooth. The successive layers are similarly treated, and thus the work proceeds until the top of the casing is reached. The ends of each portion should be finished with a slope, to which will be joined the portion next to be added longitudinally. These joinings should not, in the successive courses, be above those of the lower stage, but as in masonry and brickwork, should ‘break joint.’ The seams are all distinctly perceptible when the work is complete.”
Plastering
Plastering.—“The wall may have a coating of plaster, or the surface may be simply smoothed and dressed with a shovel, or similar implement. When it is to be plastered, it is necessary that the wall should first be thoroughly dry. If dry only externally whilst damp within, it has been found that the moisture is apt subsequently to attack the plaster and cause it to fall off in flakes. Without plaster, good Pisé work is found successfully to withstand exposure to the weather, and after the lapse of many years to be so compact and hard as to be picked down with difficulty.”
Protection.—“Where the wall is not that of a roofed building, it should be provided with a coping, having a good projection to protect it from rain.”
Rods versus Bars.—“The substitution of iron connecting bars for the wooden ones has been mentioned above. The evils of the wooden arrangement were found to be: the starting of the wedges, the fracture of the tenons, the tight jamming of the bars in the wall, and the injury to the walls and to the bars themselves from the force requisite to be applied for extracting them. The lower iron connecting bars are made 3½ in. by ½ in.; the upper, 1 in. by ⅓ or ¼ in. each, having holes ½ in. by ¼ in., with corresponding pins.
“The mode of setting the bars and arranging the work on each successive elevation of the casing is to cut on the surface of the completed part of the wall a groove 1 in. wider than the bar, filling it in, after placing the bar, with sand, to the level of the wall’s surface. The side boarding being set up, the vacant space left along the bevelled edge of the previous course is filled up with moist clay to retain the first layer of the new course. The end pieces are secured by iron bars or rods, with screws and nuts.”7
Ramming.—“Gentle and quick ramming has been found most effectual.”
Report on the Pisé-work executed at the Etah Jail during 1867-8. By Mr. H. Sprenger, Assistant Engineer
“The boxes in which the pisé-work at the Etah Jail is being executed consist of two wooden frames 10 ft. long and 2½ ft. broad, made of planks, which are nailed on to stout battens. They are held together by four pairs of posts 3 in. by 3 in., which are connected above and below with tie-bars of flat iron 1½ in. by ¼ in. The tie-bars have at each end a certain number of ½ in. holes punched in them to receive pins for the purpose of preventing the posts from slipping off. By changing the pins, walls of any given dimension can be obtained, wedges of hard wood, with longitudinal slots, are introduced between the posts and the pins, to adjust the breadth of the boxes to a standard gauge. After the boxes are fixed and adjusted, they are secured in their position by ropes passing over them, and tied to stakes on each side. Any deflection from the vertical should be corrected at the commencement of the work, as it is impossible to alter the position of a box after it is half full. Any earth which is suitable for brick-making will do for pisé-work. On being dug out it is passed through a screen with ½-in. meshes, and thrown into the boxes in even layers of 6 in. in depth.
The Right Quantity of Water
“Generally fresh earth contains sufficient moisture to ensure good consolidation; but if it is found that it jumps up under the rammers, it should, on being thrown into the boxes, be sprinkled with a little water out of a tin can with a rose. The watering should be as uniform as possible, as if it is applied unequally it will liquefy the earth, which will commence oozing out under the rammers. Pisé-work executed with too much water is worse than if done with dry earth, as, on account of the elasticity of the wet earth, the effect of the ramming is deadened, and the earth remains unconsolidated. The men should be prohibited to keep time in ramming, as it causes vibration, which is injurious to the stability of the wall. On working over a lower course, it is as well to let the lower tie-bars about 4 in. into the same to give the boxes a firm hold on the old work, thereby the joints become imperceptible, and the upper edge of the lower course is prevented from chipping off.
“The implements used are three different kinds of rammers. The earth is first beaten down with a V-shaped rammer, and then surfaced with one with a flat bottom. The sides of the boxes are consolidated with a spade-shaped rammer. When commencing the pisé-work at Etah, considerable difficulty was experienced in extricating the lower tie-bars. These were, therefore, supplied with holes 3 in. apart throughout their whole length. A pin was inserted, against which a crow-bar with a long slot and well bent at the end was made to work. An equal pressure could thereby be exerted against the tie-bars; they were thus extracted with great facility without injuring them or the face of the wall, which was not the case formerly.”
Supplementary Note by Mr. E. Battie, Executive Engineer, 5th Division, Grand Trunk Road
“The work at Etah has generally been concluded in the following manner: In the morning the boxes were taken down, and again put up and filled during the day; they were left during the night, so that the earth might detach itself from the sides. It is not advisable to allow a course to dry thoroughly, as the upper one will not bind well into it, but probably show a crack. If the earth is well rammed, and only the proper quantity of moisture admitted, a second course can be commenced immediately.”
The Report of the Rhodesia Munitions and Resources Committee issued in 1918 contains an interesting paper by Mr. John Hynd on Pisé-building, from which the following is extracted:
Pisé Buildings at Empandeni
“Pisé de Terre Buildings
“The Spectator took this matter up some two years ago and wrote as follows:
“‘Various schemes of land settlement are in the air. . . . All of them must, however, be concerned with cheap buildings. That is a sine qua non.’ . . .
“The material used for the walls at Empandeni is one-third sand, one-third ant-heap, and one-third soil, all pulverised and put through a sieve. Water is then added. The mixture must be neither too wet nor too dry, just sufficiently damp to bind; a good indication of the correct consistency being that when squeezed hard by the hand it shows a tendency to bind. Sufficient of the loose mixture is thrown into the form to fill it to a depth of about 3 in., and this is thoroughly rammed before the next layer is put in. Most thorough ramming is essential. When the frame is rammed full, it is taken apart and shifted along to make another section and so on until the first layer is complete. The first layer is, as a rule, sufficiently dry to permit the starting of the next about three hours after laying. Door and window frames are put in as the work proceeds, and must be well braced while ramming. In the top layer hoop iron or fencing wire is let in for fastening down the wall plates. Arsenite of soda or Atlas Compound is used in the first layer or two to keep out white ants. The floor can be made of timber, cement concrete, or rammed earth, and the roof thatched or covered with corrugated iron as is most convenient.
“The following Pisé de terre buildings have been erected at Empandeni:
“A large schoolroom 75 ft. by 28 ft. by 12 ft. high, walls 14 in. thick; seven boys’ dormitories, each 30 ft. by 20 ft. by 12 ft.; twelve single-room houses, each 16 ft. by 12 ft.; six fowl houses, each 20 ft. by 10 ft.; a large fowl house 250 ft. long, front walls 7 ft. and back walls 5 ft. high. This building is divided into fifteen compartments.
“From the foregoing description it is quite evident that cheap and efficient buildings of this nature can be erected at a very low cost.
“On a farm it is not necessary to employ any skilled labour, as the doors and windows can be purchased ready-made, and the frame-work, clamps, etc., put together by the farmer himself. For a roof of thatch all the necessary material, except iron ridging, if this is used, can as a rule be procured on the farm.
“Should a cement concrete floor, which is cheaper than a wood one, be desired, there would be an extra expenditure for cement, the amount required being about two bags per twelve square yards. Such a floor should be laid before the walls of the building are commenced, and it is essential that the site is thoroughly well rammed and consolidated, particularly below where walls will come, before laying the concrete, to prevent cracks developing through settlement. The concrete raft should be carried at least 6 in. beyond the outside walls of the building, and if the work is properly done, a special ant-course will be unnecessary. The concrete can be left rough below the walls to give a bond, and it might be advisable to lay some pieces of hoop iron in it which would be left projecting to be bedded into the walls.
“Another good type of floor would probably be that suggested in The Spectator, viz. road material laid down and tarred in the same manner as roads are now made in many places.
“A number of rooms and houses have been erected on the Globe and Phœnix Mine on much the same principle as Pisé de terre buildings, but the system developed there is different as regards the mixture, which consists of two parts ant-heap or ordinary dagga which must not be too sandy, and three parts ashes or clinker sieved free from fine dust.
“A very full description of the method employed on this mine was forwarded by the courtesy of the Manager to the Committee, and it is interesting to note from this that the walls are made waterproof by first making them smooth with dagga plaster, then, when quite dry, giving one good coat of boiling hot tar. A coat of limewash is applied three days later. That this is effective is well evidenced by the fact that the buildings erected have successfully withstood our last abnormally heavy rainy season.
“The Globe and Phœnix system is the result of a number of experiments carried out on that mine. Their mixture, which is stated to be ant-proof, contains more moisture than Pisé de terre, and each course is reinforced with old wire rope, or other suitable scrap. The material is left in a heap for one or two days before being used.
“Circular huts have been built on the mine of the same material, the forms being made of two rings of corrugated iron in three or more sections joined up with cleats at the end laps and held in position with cross bolts and distance pieces. The inner ring is 9 in. less radius than the outer one.”
Pisé Buildings for Settlers
Extracts from a paper on Pisé in the “Farmers’ Handbook,” issued by the Department of Agriculture, New South Wales, 1911
“Pisé is a material readily obtainable by the settler, of which cheap and durable buildings can be easily and substantially erected.
“For the construction of pastoral or agricultural buildings, especially in districts remote from railways, or from towns in which other building materials are cheap or easily procurable, pisé is particularly well adapted. In the country earth is plentiful and readily obtainable; in the city or town such is not the case, and this fact, combined with the very bulky nature of the material, prohibits its use in such centres of population.
“To the selector or settler, who, like many of our successful pioneers, is not burdened with a superfluity of hard cash, but who possesses an abundant capital of energy, combined with a certain amount of handiness, pisé has an additional advantage (which it shares with slabs, wattle and daub, etc.) over most other building materials, in that it affords him an opportunity of erecting his homesteading largely as the result of his own labour.
“As a building material, pisé is infinitely superior and more durable than slabs, galvanised iron, or weather-boards. In fact it is questionable whether it is not more suitable for our climate, and therefore to be preferred to brickwork; for pisé buildings, properly protected and finished, are quite as durable and much cooler than buildings constructed with solid brick walls. This statement may be questioned by some whose knowledge of pisé is limited to buildings so badly planned that the very elementary principles of building construction have been neglected. This neglect, which is all too common, makes things bad enough, but when to it is added, as is sometimes the case, indifferent workmanship, combined with the use of unsuitable material, the result does not call for admiration, and it is not surprising that a bad impression is created. With no other knowledge of pisé it is only natural to condemn it because of such specimens, but under similar circumstances other better-known building materials of proved excellence would also be condemned. Brickwork would just as readily be condemned if its building qualities had to be estimated by the appearance presented by a brick building which had been constructed of badly-burnt bricks laid by unskilful tradesmen on an imperfectly thought-out plan. Just as with other building materials, the possibilities of this material can only be judged by an examination of properly planned and constructed examples of the pisé-builder’s art. Such are found here and there throughout the country, pleasing to look at, affording comfort and satisfaction to their owners. A properly constructed pisé building can be finished to suit the taste of the most fastidious. Even without plaster the walls can be ‘floated’ down and a ‘skin’ obtained on them which, when limewashed, resembles stonework. When plastered inside and out they possess the advantages of a stone house, and are erected at a fraction of the cost.
“Some idea may be formed of the durability of pisé by the fact that there is a stable built of pisé which has been in constant use for over sixty years, and which at the present time is in good order. The good condition of this stable is the more surprising because the external walls are unprotected from the weather, and it is generally recognised that pisé-work, especially if unplastered, should be protected from the direct action of rain. Pisé buildings are said to have a life of a century and a half.
“The stability of pisé buildings is beyond question, as is proved by the following instance:—At Lambrigg, a second-story brick building, with 14-in. walls, and containing ten rooms, is built upon a lower story of pisé. The bricklayer who had the contract for erecting the brick portion of the house refused, as it was built upon pisé, to guarantee his work. Some time after the completion of the house he visited it, and after a thorough examination of the building, declared that it was the most substantial brick house in the district, as it had not a crack in it, a feature which was somewhat unusual in that locality. Another case bearing on the same subject is that of a residence at Temora. When this building was being constructed the workmen omitted to leave holes for the bolts which were to secure the verandah plates to the walls, as it was thought these could readily be bored out afterwards with an auger. On attempting to bore out these holes on the completion of the building, and when the pisé-work had become drier, the operation of boring proved so difficult as to be practically impossible, and had to be abandoned.
Builders’ Aversions
“The merits of pisé-work have been recognised in France, India, Mexico, and California for years past, and seeing its equal suitability for our climate, it is surprising that these merits have not led to its being more extensively used. The principal reason for this seems to be because our builders are averse to undertaking this class of work, and in consequence the bulk of it is placed in the hands of untrained men, who, whilst quite fitted to carry out the pisé-work, are not competent to undertake the other constructive work of a building. However, they do not hesitate to do this, as well as to undertake the more important work (though unrecognised as being so) of planning out the building. The result is in most cases an improperly planned and defectively constructed building, which appeals to no one, but has a tendency to bring pisé into disrepute.
“The reason for a builder’s unwillingness to undertake pisé-work is not far to seek. For the successful carrying out of his work a builder relies upon skilled tradesmen; our tradesmen are trained in cities and towns, and as pisé is not a suitable material for such places, tradesmen do not become familiar with it. A good builder with a reputation to lose shrinks from placing that reputation at the mercy of a pisé-builder, who is not recognised as a tradesman, and in whom, in consequence of this, a builder is likely to have little or no confidence.
“The actual erection of pisé-work presents so little difficulty that it can be done by any one who has sufficient strength to shovel earth and wield a rammer, provided he will exercise care to see that the moulds or boxes into which the earth is shovelled are kept plumb and in straight lines. The average settler, even with no previous knowledge of pisé-work or building construction, need have no hesitation in undertaking the pisé-work of his own buildings if he works to a well-thought-out plan drawn up by somebody competent to do so.
“The necessity of having a plan prepared by some one who understands the principles and requirements of simple building construction, before undertaking the erection of any building, cannot be too strongly emphasised. This great need, which is often overlooked by the settler, cannot be economically dispensed with. The securing of a properly prepared plan is of the greatest value towards obtaining a building of the maximum strength and durability, combined with the best appearance and greatest convenience, for the least cost. Even when a settler undertakes the pisé-work of his own building, it will only be in rare instances that he will not have the advantage of trained supervision during its erection. The services of a tradesman will invariably be found necessary to make doors and window-frames, construct the roof, etc. This workman can be engaged when the building is started, and whilst preparing the timbers of the roof, in readiness for the time when they will be required on the completion of the pisé-work, can supervise the fixing of the door and window frames, and see they are set correctly, and in their proper places.
“Pisé walls are constructed in sections, the extent of which is regulated by the supply of casings available.
“Into the moulds formed by the boxes the earth is shovelled in layers of 4 or 5 in., and then rammed until thoroughly solid before another layer is put in. On the completion of the section, i.e. when the mould is full and well rammed, the keys or pins are knocked out of the ‘bolts,’ and the ‘boxes’ taken apart and erected on another portion of the building. The top of that portion of the pisé-work on which it is proposed to erect another section should be well moistened and covered with wet bags some hours before the mould is formed. The bottom of the mould should overlap the top of the pisé-work by about 6 in. After the ‘boxes’ are put together, the top layer of pisé should be loosened with a pick so as to form a bond with the section about to be built, and if this section adjoins one already built, the ends of the latter should be bevelled off so as not to form a straight joint.
“Material which is too sandy will fret away, and one containing clay will crack when dry. Soils containing these defects should be avoided. There is, however, such a wide range of soils which are suitable that a holding of any size on which suitable soils cannot be found will be the exception. It is possible to remedy the defects found in one soil by mixing it with another soil, but very rarely will such a course be necessary.
Number of Men Required
“The plant required will depend upon the number of men to be employed. Three is the least number that can be economically employed—two attending to the boxes and ramming, and one carting earth from its location to the building and assisting generally. The plant required for this number of men is given below. If more are engaged, additional plant of the same character will be found advantageous.
“The necessary plant will consist of—2 wooden rammers, 1 iron shod rammer, 2 straight boxes, 2 angle boxes, 3 casings for blocking up the ends of boxes, bolts and keys for same, 12 gauge rods, washers—a liberal supply of ¾-in. washers, 2 shovels, 1 spade, a horse and dray or other means for transporting the material to the building (if required).”
The following detailed instructions are taken from the same authority:
Pisé in New Zealand
SPECIFICATION CLAUSES FOR A PISÉ HOUSE (NEW ZEALAND)
Excavator.—Remove the turf to make footings, but not deeper at any place than 3 in. Step where required.
Pisé-Builder
Walls.—Erect the walls as shown on plan, external walls 18 in., internal walls 15 in., carried up plumb and true, with all cross walls properly bonded by continuing the pisé-boxes around all angles; when necessary, the material for the walls is to be properly tempered with sufficient water. All sticks and vegetable matter are to be removed.
Suitable material: to be a pipeclay loam, with a trace of small gravel evenly distributed through it.8 The boxes to be filled in thin layers of 4 in. at a time, and well rammed until solid; the workmen are not to use their rammers in unison.
The whole of the internal angles, also door and window jambs, to be neatly splayed.
Floating.—Moisten well the outside and inside walls before the floors are laid, and float same to even smooth surface with wooden hand-float, using weak plaster, where required.
Bolts.—To hold down wall-plates, provide and build in ½ in. bolts, not less than 15 in. long, and spaced not more than 6 ft. apart.
Damp-course.—Below all walls lay a three-ply Ruberoid damp-course the full width of walls, to lap at ends at least 4 in.
Ventilators.—Insert below floors, where directed, four 9 in. by 6 in. galvanised iron air gratings, in wooden frames 1½ in. thick by full width of walls; also insert at about 18 in. below ceiling similar air gratings and frames.
Plugs.—Insert plugs 3 ft. apart for skirting, chair and picture-rail, at the heights directed.
Frames.—Set all frames plumb and true, and secured in wall before removing head. Lintels and heads must be well and solidly bedded in mortar, at proper heights. The whole of the work to be done in a proper workmanlike manner.
Fillet.—Finish against intersection of floor and wall with neat 1½ in. quarter-round fillet, scribed to wall and floor and nailed to floors.
The pisé-builder will require to build into wall at all window and door openings 3 in. by 3 in. shaped plugs, spaced not more than 3 ft. apart to secure architraves.
Lintels.—For all door and window openings provide 6 in. by 4 in. well-seasoned pine lintels, to extend 12 in. into pisé-work on each side of opening.
Skirting.—Provide and fix in all rooms, to plugs about 3 ft. apart, 6-in. skirting, neatly scribed to floors, mitred at angles as required.
Picture-rail.—Provide 3 in. by 1 in. picture-rail to all rooms.
Plugs.—Prepare and tar for pisé-builder 3 in. by 1 in. well-seasoned softwood plugs, 15 in. long, as per detail, for skirtings, picture- and chair-rail, to be inserted 3 ft. apart.
STUDDING, WIRE-NETTING, AND PISÉ
“This is a modification of Pisé, which provides a settler in a district where poles and saplings are available with a quick method of providing himself with a comfortable temporary residence without the expenditure of much cash. To construct buildings of this character, a framework of saplings or poles, at intervals of 3 ft. 6 in. to 3 ft. apart, is first erected; this framework is covered on both sides with 1¼ in. mesh wire-netting. The two sections of netting are held together, strengthened, and prevented from stretching and bulging between the posts by means of wire hooks or loops, which are as long as the posts are wide. The spaces thus enclosed by the netting and the poles are then filled with earth, which is well rammed, thus making a solid wall 4 in. to 6 in. thick. This wall can be plastered, the plaster forming a key with the wire-netting, which holds securely. Buildings of this character can be made to look rather attractive, and, if neatly constructed, are very much superior, both in appearance and comfort, to slabs or wattle and daub.”
Pisé Shuttering
PISÉ SHUTTERING
I
That the plant now commonly in use for pisé-building is but a slight improvement on the anciently accepted model, may be seen by a comparison of modern examples with old engravings and descriptions. Pisé-building lay off the great main stream of constructional activity, and the enterprise and ingenuity lavished on the perfecting of other building materials and methods passed Pisé by, leaving it undisturbed in its quiet backwater, a primitive system still with its primitive tackle.
Yet there were a number of very obvious and unnecessary shortcomings in the accepted shuttering that seemed to clamour for attention, defects, too, that were in no way inherent, but merely traditional infelicities reproduced in succeeding models that remained remarkably true to their primitive ancestral architype—the Pisé plant described by Pliny.
Here seemed to be a very promising field for an ingenious inventor, a field that is still “To Let.”
In the absence of any such inventive genius, the author has had certain ideas of his own embodied in the “Mark V” type of shuttering—a type that further experience and experiment will doubtless modify.
The principle of the building-process remains unaffected. The improvements, such as they are, are merely improvements of mechanism.
DIAGRAM OF MARK V PISÉ SHUTTERING
Larger
View
Mark V Shuttering.
Showing top cross-braces thrown back and free leg disengaged.
see caption