Timber Houses. In describing the method of building in concrete (see Vol. on " Brickwork and Masonry," Advanced Series), we gave an illustration of a method of erecting the framework of a timber house, put together in the way usually employed in general practice, and which the student will find illustrated in the next paragraph, where we treat of joints. We believe it will be useful to the student, and interesting in a general way, if we describe here a method of constructing timber houses, introduced and now largely practised in America, which some practical men there say has none of the defects which the older fashioned method, in their belief, possesses. The new style of putting timber together claims to be not only more quickly put in hand than the old method, but enables much lighter materials to be used; hence saving expense in first cost, dispenses with many, if not nearly all, of the usual operations of "carpentry;" thus saves money in labour; and, lastly, gives with lighter materials stronger structures. So far as a strict examination of the principles of this system of timber framing, and a review of the large number of structures which have been built upon it, show, it is difficult to believe otherwise than that these important claims have been and are fairly met.
The system is named the "Balloon Frame System," although why that name has been given to it we fail to see, unless indeed upon the principle of "lucus a non lucendo;" inasmuch as the buildings once fixed on solid earth will be so firmly attached thereto, that the heaviest hurricane will not make them, balloon fashion, fly. Be this as it may, we now proceed to note the chief details of the system thus oddly named. The principle followed out in the system is the employment of the timber in such a way that all the strains, or as many of them as possible, shall be made to act in the direction of the length of the fibres of the wood, thus taking advantage of the strongest characteristic of wood, namely, its tensile strength, which is on the average one-fifth of that of wrought-iron. Timber thus employed can be used of much less thickness than usual. Another feature is dispensing almost entirely with cutting the timber so as to obtain notches, scarfs, tenons, etc., all these, with one exception (fig. 305, at a b c) being dispensed with; and the securing of the various parts together being made dependent entirely upon the nails. These are driven, as will be seen from the diagrams, diagonally, rarely, if ever, at right angles to any part. The value of the "diagonal" principle, applicable as it is to a great variety of mechanical purposes, is not so well known and acted upon as it ought to be. The adoption of it in this case, acting in conjunction with the plan of dispensing with the usual methods of notching and cutting the timbers, tends materially to give the maximum of strength with the minimum of material in the structure.
The first part of the work to be done, say in building a cottage on this system, is the laying of the sill, a a, fig. 301. This may or may not be laid down upon a base of brick or stone, which some would deem necessary to keep off the damp from floor of house; but if the student will observe the arrangement shown in fig. 301, he will come to the conclusion that the floor will be drier than nine-tenths of the floors of cottages as usually built, and this from the distance kept between the surface of the soil - ever more or less damp, rarely dry - and the flooring boards b b. Still further, to secure dryness the space thus left may be filled with clinkers or non-absorbing materials. If, before the flooring boards b b be laid down, a layer of smithy clinkers or coke be put between and under the joists, the floor will be a very dry one. Of course it will be necessary to level the foundation or site upon which the sill a, fig. 301, is laid, and if the site or surface of soil within the boundaries of the sill be excavated or hollowed out a few inches deeper than the surrounding level, the house will be so much the drier, especially if the layer of clinkers be added as already specified. The sills for ordinary sized buildings - indeed for the general run - is eight inches by three, but six inches by three will suffice for small buildings. The sills may simply meet at the corners, the end of the side sill butting square up against the side of the sill at the end of the building, or if preferred the two sills may be spliced or scarfed with a half lap joint, as shown at a b in fig. 302. But this is opposed to the principle of the system. The sills being laid all round the outline of the building, and perfectly level - the level being tested by a spirit level or by a mason's square level - the next operation is putting up the vertical upright posts called " studs," as c c in fig. 301. The ends of these which rest upon the sills a a must be sawn off perfectly square. The scantling or dimensions of the studs is four inches by two, the length is immaterial, that is, the studs need not at first be cut to the exact length before being set up, as they can all be easily cut when necessary. The back stud must be held in place till nailed, the nails being driven in diagonally; four nails are used to each stud, two to each side. The stud must be kept temporarily in position by nailing two laths or pieces of wood to act as stays or struts to the stud and the side of sill. The distance between each stud, from centre to centre, is sixteen inches, excepting at those parts where windows and doors are inserted; at such points the distance between the studs corresponds to the desired width of window or door opening. Each stud is set up, stayed with the lath when got "plumb,'" and then nailed to the sill. The "studs" at the corners, for large buildings used for storage, should be 4 inches square, as at c c in fig. 302, and some prefer to put them in this size even for cottages; but for this class of structure, and for other small buildings, the best plan is to set the studs at the corner, as shown in fig. 303, in which two studs of the dimensions of all the others, four inches by two, are placed so that the end of one, as a, butts against the side of the other, as b, c being the joist. After all the studs are placed and nailed in their respective positions, the next operation is putting in the joists d d, fig. 301, the dimensions of which for the ground floor are seven by two inches. These are laid on their edges resting at their ends upon the sills, and coming close up to the sides of the studs; the ends of the joists must be flush with the outside of sill and stud, as shown in figs. 301 and 302. Each joist has two nails at the end, one driven into the side of the stud, the other into the face of the sill, and both driven diagonally.