Part 7 (2/2)

ON THE BOND TIMBER TO BE USED IN BUILDINGS OF PISe

_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 pise.”

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 pise 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 pise such boards have always been found perfectly sound, 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 pise 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 pise.

”The boards above mentioned need only be placed at the angles of the exterior wall, and in those parts where the courses of the part.i.tion 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 quant.i.ty 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 part.i.tions; the several parts deriving mutual support from one another, and the whole being rendered compact and solid.”

[Headnote: The Strength of Pise]

_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 pise, 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 pise 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 pise 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 QUANt.i.tY OF PISe

_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 pise.”

_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 quant.i.ty 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 pise 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 workmans.h.i.+p 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 Roch.e.l.le, 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.

[Headnote: A Pise Church]

_A Pise 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 pise, 18 in. thick, and crepe, 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 quant.i.ty, 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 Pise 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.

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