Building

Building en Pis. An extremely simple, durable, and economical method of building walls, in very general use in the neighbourhood of Lyons, and which has been introduced into this country. It consists simply in ramming earth firmly between moulds formed of boards set upon the ground-plan of the walls; and although it may seem that buildings erected upon this plan must resemble the mud cabins which disfigure many parts of this country, they nevertheless differ widely both in appearance and durability, since they may be made as neat as brick buildings, and equally durable, houses of 150 years standing, built in this manner, being by no means rare in France. The follow ing instructions for this mode of building are taken from a paper in the Trans actions of the Society of Arts, Vol. XXVII. by Mr. Salmon, who has practised it to some extent on the estate of the Duke of Bedford, at Woburn. The only tools necessary for building en piss, besides the ordinary ones used in building, are the moulds and rammers. The mould consists of two side pieces, each composed of two planks 12 feet long, 10 inches wide, 1 inch thick, strengthened by several pieces of board nailed across them on the outside, at equal distances apart. Holes are made through these pieces of board at top and bottom, to receive iron bolts, which hold the two boards parallel to each other, 14 or 16 inches asunder, which is the thickness of the walls intended to be formed between them. The bolts have a large head at one end, and a key passes through the other to keep the planks together. Two boards, equal in length to the thickness of the wall, are placed between the planks at the ends to form the ends of the mould. The rammer consists of a short staff with an iron head, which should not be more than half an inch wide on the edge, in order that it may more forcibly compress the earth in every part, which a fiat rammer could not do so well. In forming the angles of a building, four mould boards are requisite : each of the boards for the internal angle have two eye-bolts through, and the boards being set together at the proper angle, a bolt is passed through the four eye-bolt, forming a kind of hinge ; the boards are retained in their position by an iron stay, hooked into a staple in each of the boards. The boards for the outer angle are connected by two short pieces of iron projecting from one of the boards which pass through corresponding holes in the sides of the other board near the end, and are keyed up on the outer side of the mould. The process is conducted as follows :—the foundations of the intended building must be laid of brick work, stone or rubble, and be carried at least 9 inches above the surface to protect the pig from the rain; the mould frames are then set up on the foundation walls and bolted together, the thickness of the foundation, regulating the distance at bottom, which distance is maintained at the upper part of the mould by pieces of wood cut to the proper length, which are laid upon the upper connecting bolts ; head boards are also placed at each end to retain the earth. Loose earth is then thrown into the mould to the depth of about 3 inches, which is afterwards drawn back, and cleared from the face of the mould, and the space filled up with a facing composition, forming, on an average, about an inch in thickness ; the whole is then firmly rammed (on which, and properly preparing the facing stuff, the perfection of the work will greatly depend,) until it is quite hard, when it will be compressed to about inch in thickness. The common facing stuff is composed of lime, one part, and earth, the same as that used for walling, three parts. These are mixed together, and slaked the same as mortar, and the more it is wetted and slaked the better, provided time can be allowed for it to dry again and pulverize, so as to be fit for ramming. The better sort of facing stuff may have a small quan tity more of lime in it. When by the repeated addition of layers of earth, well rammed down, as before described, the mould is filled, the keys are to be taken out of the bolts, and the bolts drawn out; the planks are then removed, and put together again another length along the wall; but the bolts at one end being put through the holes left in the wall, only one of the end boards is now required; the earth is then thrown in and rammed as before, and the process is continued until one course of all the walls is completed. When the lower course is finished, the mould is taken to pieces and put together upon that course, the lower bolts of the frame being put through the holes which the upper bolts made in the wall at the first operation ; but in order that the ver tical joints formed between each mould should not coincide in the several courses, the end board is in the first set of the moulds for a new course, set at the middle of the length of the moulds, so that the work shall form a break joint, as it is termed in brick-work, with the course below. Windows and doors

may be left in the walls by fixing the heads of the moulds, and carrying up quoins to form the same ; in erecting which some bond timber should be laid in coarse mortar, and rammed in with the earth ; lintels may also be laid at the proper height. This method is the cheapest where only one window or door of a size is wanted ; but if many are required, the readiest way would be to make some rough frames of boards, of equal width to the thickness of the walls, and place them in the situations of the windows and doors. When done, the earth is rammed up to them, laying bond timber on the sides, and lintels over them. In both cases the windows and door frames are to be put in their places, and fastened to the bond timber after the walls are up. The bond timber, lintels, and plates, should be kept as thin as possible in order to prevent any disagree ment between the earth and timber in the shrinking or drying of the same. The bond timbers may be 4 inches by ; floor or wall plates 6 inches by 2 ; lintels about 4 inches thick. For common cottages, when the whole of the walls are up and covered in, the holes should be stopped with very coarse mortar, made the same as the facing stuff, but used wetter, and after standing some time to become thoroughly dry, may be either lime washed or finished with rough cast; but if it be required to make the finishing as perfect as possible, the following is the best mode; viz. with water and a brush thoroughly wet and soak the wall for two or three yards, in superficies, at a time ; all which parts, during the said wetting, should be worked about with a band float until the face be rubbed smooth and even, by which the facing composition will so wash up as to become a pleasant regular colour, the face smooth and hard when dry, and not liable to scale off as a coat of plastering would do. It should have been mentioned before, that, as it frequently happens that the top of one course becomes too dry to attach to the succeeding course, it is advisable that, as soon as the frame is set for the succeeding course, a small quantity of thick grout, composed of I lime and I earth, be poured on the top of each course imme diately before the first layer of earth is put in. A very small quantity is sufficient, and will add much to the strength of the work by cementing the courses well together at the joints. The workman should also, with the corner of his rammer, in ramming home to the upright joints, cut down a little of that part of the wall up to which be works: this will make the upright joints key together, and unite in a solid manner. The earth proper for this work should be neither sand nor clay singly, but a mixture of both. Clay is very objec tionable, as is also chalk, or calcareous earth of any sort. Sand is also not proper, unless accompanied by some binding property ; the bolder and coarser the sort of earth the better. When used, it should retain no more moisture than just to make it adhere under the pressure of the thumb and finger. Where the earth is not by itself proper, it may generally be rendered so by admixture with either clay or with coarse sand, as the case may require. With respect to the expense of this sort of walls, Mr. Salmon observes that, as labour is the principal part of that expense, and as in some places labour is dearer than in other, the best mode of estimating it at different places is from the quantity that a man should do in a day, which he has found is 1} yard in the common day's labour of ten hours. At Woburn he estimated the expense as under:— At the same place, the value of a yard of brickwork is more than ten shillings, of walling only 14 inches thick, the bricks being forty-two shillings per 1000, and lime eightpence per bushel; consequently the economy of pis4 must appear ; and the same difference will be found in any other place where lime and bricks bear the same price, and proper earth can be found at hand. But it must not be concluded that the entire expense of a building will be in the same proportion ; the economy of piss over brickwork applies only to the walls of a building, the roof, floors, fittings, &c. will be nearly the same in both cases, and even as regards the walls, the brickwork of the foundations must be taken into the calculation.