In most districts slabs or weatherboards with bark or iron roof are the first materials that suggest themselves to the home builder. For our climatic conditions, however, a much more comfortable, and, in many sparsely timbered districts, more economical dwelling can be made of pise.
Pise is a material readily obtainable by the settler, of which cheap and durable buildings can be easily and substantially erected. Such buildings possess the advantage of maintaining a fairly uniform temperature throughout the year. They are warm in winter and cool in summer, and therefore possess distinct advantages for a climate such as prevails over a wide area of New South Wales.
For the construction of pastoral agricultural buildings, especially in districts remote from railways, or from towns in which other building materials are cheap or easily procurable, pise, which is simply earth or soil shovelled into temporary casings, which regulate the forms and dimensions of the walls required, and then rammed until thoroughly solid, 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 or hard cash, but who possesses an abundant capital of energy, combined with a certain amount of handiness, pise has an additional advantage (which it shares with slabs, wattle and dab, etc) over most other building materials, in that it affords him an opportunity of erecting his homestead largely as the result of his own labour.
As a building material, pise is infinitely superior and more durable than slabs, galvanized iron, or weatherboards. In fact it is questionable whether it is not more suitable for our climate, and therefore to be preferred to brickwork: for pise buildings, properly protected and finished are quite as durable and much cooler than buildings constructed with, solid brick walls.
Just as with other building materials, the possibility of this material can only be judged by an examination of properly planned and constructed examples of the pise 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 pise 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.
Pise work is very slightly dearer than galvanized iron and studding, cheaper than weatherboards, and about half the cost of 9-inch brickwork.
Some idea may be formed of the durability of pise by the fact that there is at present (1911) at "North Logan" a stable built of pise which has been in constant use for over 60 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 pise work, especially if unplastered, should be protected from the direct action of rain.
Pise buildings, are said to have a life of a century and a half.
The stability of pise buildings is beyond question, as is proved by the following instance: - at Lambrigg, a second-storey brick building, with 14-inch walls, and containing 10 rooms, is built upon a lower storey of pise. The bricklayer who had the contract for erecting the brick portion of the house refused, as it was built upon pise, 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 that was somewhat unusual in that locality.
Another case bearing on the same subject is that connected with the residence of Mr A. Donaldson, Sproule's Lagoon, Temora (NSW). 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 be readily bored out afterwards with an auger.
On attempting to bore out these holes on the completion of the building, and when the pise work had become drier, the operation of boring proved so difficult as to be practically impossible, and had to be abandoned. Fortunately, by slightly raising the position of the verandah plate it was possible to make use of the holes left when the bolts used for holding the "boxes" together were withdrawn.
The merits of pise 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 actual erection of pise work presents so little difficulty that it can be done by anyone who has sufficient strength to shovel earth and wield a rammer, provided he will exercise sufficient 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 pise work or building construction, need have no hesitation in undertaking the pise work of his own buildings if he works to a well thought-out plan drawn up by somebody competent to do so. That this statement is not overdrawn is proved by the fact that the pise work of the cottage illustrated here, was done by men who had no previous experience of pise work or building construction, but who were accustomed to and are employed for the ordinary work of the farm.
The necessity of having a plan prepared by someone who understands the principles and requirements of simple building construction, before undertaking the erection of any building, cannot be too strongly emphasised. Even when a settler undertakes the pise 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 pise work), can supervise the fixing of the door and window frames, and see they are set correct and in their proper places.
Pise walls are constructed in sections, the extent of which is regulated by the supply of casings available. These casings (or boxes) regulate the shape and thickness of the walls and the height of the sections, and are made of stout planks held together by ledges or cross-planks, which should be stout enough to keep the "boxes" from warping.
The dimensions of the boxes are optional, but vary chiefly with regard to width; this ranges from 12 to 36 inches. This latter width was adopted when making the boxes used at the Cowra Experiment Farm, and it has proved very suitable and convenient. There seems no substantial reason why narrower boxes are to be preferred.
The maximum size for convenient use may be taken to be about 10 feet long and 3 feet wide. The boxes are put together so as to form moulds corresponding to the shape and thickness of the walls to be erected. They are held together by 5/8th-inch round iron rods, and kept the required distance apart by the use of pieces of batten or scantling cut to the necessary length, ie, the thickness of the walls.
As the earth is filled in the gauge battens become unnecessary, and are removed by the workmen. The rods referred to (known as "bolts") have a square bolthead at one end, and have holes pitched at various distances from the bolthead to correspond with the varying thicknesses of the walls to be erected.
Into the moulds formed by the boxes the earth is shovelled in layers of 4 or 5 inches, and then rammed until thoroughly solid before another layer is put in. On the completion of the sectton - 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 pise 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 pise work by about 6 inches.
After the boxes are put together, the top layer of pise 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 longitudinal joint.
Almost any earth containing a fair amount of loam is suitable for pise, but a pipeclay loam, with which gravel is intermingled, is best. Soil which cakes after a heavy rain, or which, if ploughed or dug, when dry turns up in hard clods, is very suitable. 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 soil 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. Any vegetation growing on the surface of the earth selected should be removed, as also should any roots, bits of stick, or vegetable matter likely to decay.
The earth is best used as it is dug, and if too dry should be brought to the correct moist condition by watering it, about two days before it is to be used. No amount of tempering after it is dug will render it as suitable as watering in the solid as described.
The earth should be just moist enough to be crumbly, and yet adhesive enough to retain the impression of the fingers when pressed in the hand. If too moist it will stick to the rammer and work up squashy; if too dry, it will work up loose under the rammer. If in that condition which is best adapted tor ramming a fence post, it is just right.
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 necessary plant will consist of: - 2 wooden rammers, 1 iron-shod rammer, 2 straight boxes, 2 angle boxes, 3 casings for blocking up the end of boxes, bolts and keys for the same, 12 gauge rods, washers - a liberal supply of 3/4-inch washers, 2 shovels, 1 spade, a horse-and-dray, or other means for transporting the material to the building.
The wooden rammers are made from hardwood, cut to the shape and dimensions shown here. These rammers are used for consolidating the bulk of the material after the corners and faces have been rammed with the iron rammer, which is a piece of iron or steel about 10 inches long, with a shank 11 inches long, forged to-the shape of a right-angled triangle and bolted to a wooden handle.
The gauge rods to regulate the thickness of the walls are made by cutting battens or round sticks into pieces as long as the walls are to be thick.
An abundant supply of washers is necessary in order to facilitate tightening the boxes to the width as regulated by the gauge rods. Wooden washers are very useful for placing next to the sloe of the box, and especially at joints. They are easily made by boring 3/4-inch holes in short lengths of battens.
The rammed earth (pise) when dry is very hard, and in this state it is very durable. Moisture in any form softens it, and so changes its character that it becomes susceptible to injury.
It is obvious, therefore, that pise should be protected from moisture in any shape or form. The danger from rain is apparent, and is guarded against by surrounding pise buildings with verandahs or overhanging eaves. Pise buildings unprotected by verandahs are not uncommon, but the economy of protecting such buildings from the direct action of rain is now generally recognised.
The danger from the moisture contained in the soil on which the building rests is not so apparent, but it nevertheless is a real one. The moisture, by the force of capillary action, will rise up into the walls and affect their stability, as well as affect the health of the inmates.
This danger is recognised int the building trade, and in brick buildings is guarded against by the-insertion of a damp-course of non-porous material, such as slate or asphalt, at the floor level. In the case of bricks, which are unsoftened by moisture, this is a suitable place for the damp-course, but in the case-of pise it should be inserted at ground level and underneath the bottom of the pise work.
Provided the grass and other Vegetation is removed, pise work can be built right on the surface of the ground (but this is not recommended - see notes). Precaution should be taken. to prevent the efficiency of the damp-course being destroyed by accumulations of soil against the wall. If this be neglected, moisture will gradually rise up through the accumulated soil in the same way that water rises up through a sponge, and thus destroy the effect of the damp-course. When, In order to obtain sound ground to build upon excavations are necessary, the foundations should be of stone, concrete or bricks. Which should be carried above the ground level.
The expense entailed by the erection of a verandah may be regarded by some as a reason against the adoption of pise as a building material; but who will say, that, in a climate such as extends over a great portion of this State, a verandah is unnecessary to protect our buildings from the heat and glare of the midsummer sun.
As air does not readilY penetrate. through pise walls, it is specially necessary that the provision made: for ventilation should be ample. This is a matter often neglected, and in consequence such badly ventilated houses are unhealthy and the rooms "stuffy" ,and ''sweaty''.
There is no difficulty in ventilating pise buildings properly. A convenient way is to make rectangular boxes of wood or concrete, the ends. of which are covered with ventilating gratings. These boxes are made as long as the wall is wide, and are built in the wall as it is being erected.
The timber used in the construction or pise buildings, for frames, lintels, sills etc, Should be well-seasoned. Otherwise, on drying, it is likely to shrink away from the pise and leave an unsightly crack. On account of the difficulty of obtaining seasoned timber, it is advisable to use no more than is absolutely necessary; and because of the simplicity with which concrete blocks can be made, it is recommended that concrete sills and lintels be used instead of wooden ones.
A serious defect met with in some pise buildings is that the internal walls are erected independently of the external walls, and after the latter have been completed. There is, in consequence, no bond between them, and what should be a source of strength to the whole building does not reinforce it in anyway. The invariable result is that, as the internal walls dry, they shrink away from the external walls, showing a division which can never satisfactorily be filled up or hidden.
Pise has its limitations; it is quite unsuited for elaborate or complicated architecture; but a careful man has in this material the means whereby he can build plain, substantial, durable, and comfortable buildings very cheaply.
Pise may be finished to resemble concrete or stonework by plastering it; but this operation should be delayed until the pise work is thoroughly dry, otherwise the plaster is apt to scale off. The plaster used should be very "poor" or weak, as it is found a poor plaster adheres more firmly to the walls, which, before they are plastered, should be roughened with a rake or other similar tool.
Cement should not be applied to pise. It is rarely, if ever, satisfactory as is - even a thin wash - invariably peels off in thin flakes. The most satisfactory method of colouring pise is to limewash it.
The boxes can be made of any wood which will hot twist or warp easily. It is an advantage to have it light and tough. Because of this cedar is the most suitable timber, but its scarcity and high price renders its use prohibitive. The boxes used at the Cowra Farm were made of redwood, and gave great satisfaction.
The size of the boxes will be governed, to some extent, by the amount of work to be done. Obviously, no one will be willing to spend a large amount for materials to make boxes for the erection of a small building.
For a small building, boxes 2 feet deep will be suitable: but for a larger building, or for several buildings, it will be found economical to have the boxes 3 feet deep. Whether the boxes are 2 feet or 3 feet deep, the construction will be the same.
The planks, 12in by 1in, or 12in by 1 1/2in, which should be planed on one side (the inside of the box), are braced and held together by 4in x 1in ledges. These ledges are preferably spaced so that, in addition to holding the planks together, they stiffen them at the places were the bolts, which hold the boxes together, go through them.
Two of the straight boxes will require to be fitted with iron attachments, so that they can be secured together at right-angles to each other, and thus, together with the angle-boxes, form a mould for making external corners. These attachments or plates are made of 3/4-inch x 1/2-inch flat iron, and are about 1ft 3in long. One of the pair, at 'a' in Figure 2, is shouldered to form at one end a ½-inch round pin, which is threaded to take a nut. When the boxes are fitted up, this bolt end passes through a hole in the other attachment shown and is screwed up as tight as is required.
Where more than two straight boxes are available some of them should be fitted with 2in x 1/4in flat iron plates, punched with 3/4-inch holes. These Plates should be bolted loosely to the ends of the boxes, as shown at 'c' in Figure 2 (left-hand side), in such a position that the holes in them will correspond with the 1/2-inch holes in the box. These plates prove very useful when joining one box to another.
A convenient length for the straight boxes is 10 feet. The angle boxes consist of two sections, permanently secured at right-angles to each other by means of braced angle brackets, which are placed so as not to be in the way of the bolts which bold the boxes together.
When the external wails are to be 18 inches and the internal ones 15 inches thick, a convenient size for the angle boxes is to have one arm 3 feet 1 1/2 inches and the other 8 feet 1 1/2 inches long, with the holes spaced as in the illustration. With this spacing the holes will coincide with the holes in the straight boxes when both are set up to build in a cross wall. If additional boxes are available they can be continued on indefinitely without the necessity of boring fresh holes.
If the thickness of the walls are other than those given, the length of the external angle boxes will be slightly different from that shown, and will be governed by the position of the first hole from the corner. For the holes in the angled box to correspond with the holes In the straight box, when fitted up, the distance from the corner of the first hole in the angle box should be half the difference between the thickness of the internal walls and the distance at which the bolt holes are spaced - Say, 2 feet 6 inches, which has been found about right.
The bolts, which together with the keys are used for keeping the boxes in position, are made of 5/8-inch round iron, with tapering keyways, as shown in Figure 5. The distances of the keyways from the head of the bolt are those suitable for 15-inch and 18-inch walls, when boxes built of 1 1/2-inch timber and 1-inch ledges are used.
The keys are made of 1/8-inch flat iron, as shown in Fig 6.
The Sections for blocking up the ends of boxes are made of the same material and in a similar manner to the boxes. The photograph below shows how the ends are constructed.
Their length corresponds to the height of the boxes, and their width to the thickness of the wall being built, or to the space - at window or door frames - to be blocked in. They are kept in position by the bolts which hold the boxes together, and, when necessary, by packing between the ends and the bolts.