Slating. With slating or tiling greater care is necessary than with shingles. Neither slates nor tiles will lay as closely to the roof, or to each other, as shingles, and for this reason, the boarding should always be matched, and tarred paper always used, as circulation of air is no object with slates. The lap of slates should vary with their length, always allowing at least three inches head-cover, that is, each slate must lap three inches below the head of the second slate below it. Tiles are constructed with a variety of joints and laps, each designed for the needs of the different forms of the tiles. Both slates and tiles should be put on with galvanized nails, which must not be driven too hard for fear of cracking and yet hard enough to prevent loosening or rattling, and if the cost is not too great, copper should be used for all gutters and flashings. It is a good practice to lay the first three or four courses of a slate roof above the gutter in elastic cement, and also all hips and ridges.
Window Frames, Following the completion of the roof will come the preparation of the side walls to receive their finish, and the first thing to be done is to set the window frames. In wooden houses the stud will usually make one side of the weight box, and the frame will consist only of the "pulley stile" and casing. Sometimes the boarding is kept back from the edge of the studding and the casing is set upon the studding with a piece of finish or a "back-band", put over the joint with tarred paper, or better still, strips of zinc, to keep out the water. (Fig. 38.) In case the frame is set against the usual four-inch studding the outer casing will form one side of the groove in which the sash slides, but in the other case there will be room to put a strip,five-eighths or three-quarters of an inch wide inside of the casing, moving the sashes in and leaving a space for mosquito guards. (Fig. 39.) The top of the frame must be flashed with lead and the bottom of the sill grooved, to receive the top of the shingles or clap-boarding, which will be begun as soon as the frames are set. Pockets of canvas, in which the window sill is set, are advisable in exposed situations.
Porch and Piazza. Before the clapboarding or shingles of the walls can be completed, the porch and piazza finish must be putt up. The floors should be framed with the joists running parallel with the house walls so that the boards will run in and out, and they must also pitch away from the house at about the rate of two inches in twelve feet. The tops of the piazza joists should be set about six inches below the main house and it is a good plan to bevel off the tops, leaving only a nar row edge for nailing, so that the water, which will rim be tween the joints if the floor is open, will find little surface to remain upon. (Fig. 40.)
Sometimes the joists and girders are covered with tarred paper. The roof of the piazza, which is covered with tin, will need especial attention to see that it is given a proper pitch and that the tin is turned up against the boarding of the house wall at least six inches to be clapboarded over. The quality of the tin should be examined and care taken to have it painted on the under side before being laid, and that the joints are well locked and soldered. Blocks must be set on the tin roof and flashed and soldered, to which the balcony posts are to be secured; and where the finish of porch or piazza ends against the house, great care must be taken that the connection is thoroughly flashed with lead.
Clapboarding and Siding. Clapboarding is done in sections, from staging successively lowered as the work progresses. Each section is built upward from the staging, its top board being slipped under the lowest board of the preceding section, which has been left unnailed along the bottom for that purpose. The term "clapboard," in New England, corresponds to "siding," as used elsewhere. Clap boards are all quarter-sawed, being cut from the log by a circular saw which cuts always toward the center; they are cut four feet long, six inches wide and half an inch thick at the butt. Siding is of similar section but a little thicker, and is commonly sawed the same way as boards, in lengths of twelve to sixteen feet. Either clap boards or siding make a good wall cov ering, and the best should always be quarter-sawed and laid over a good quality of sheating paper, which is gen erally put on in horizontal layers, each layer being lapped about two inches and breaking joints with the paper and flashings already put behind the finished work.
There are many good brands of paper on the market, with very little to choose between, the principal qualities required being tough ness and soundness. -A kind of siding called "novelty siding" is often used for cheap summer houses. This is nailed directly to the studding without any rough boarding, but the omission of the rough boarding—it should be noted—is always done at a great loss in strength and warmth.
Wall Shingles. If the walls were to be shingled, the same care would have to be taken as in shingling the roof, except that the shingles on the wars may be exposed five or six inches and they may be of a quality called "clears," in which the exposed lower third is free from imperfections. Shingling undoubtedly makes a warmer coating than clapboards or siding, as there are always three thick nesses of shingles to one of clapboards; but the choice between shingles and clapboards is generally determined by the character of the building and the effect desired.