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Porch and Piazza. Before the clapboarding or shingling of the walls can be completed, the porch and piazza finish must be put up. The floors should be framed with the joists running parallel with the house walls so that the boards will be perpendicular to the walls, and the floor boards must also slope away from the house at about the rate of 2 inches in 12 feet. The tops of the piazza joists should be set about 6 inches below the main house, and it is a good plan to bevel off the tops and leave only a narrow edge for nailing, so that the water, which will run between the joints if the floor is open, will find little surface upon which to settle, Fig. 45. 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 6 inches, where it will be clapboarded over. The quality of the tin should be examined, and care taken to have it painted on the underside before being laid and to have the joints well locked and soldered. Blocks must be set on the tin roof and flashed and soldered, to which the balcony posts can be secured; and where the finish of porch or piazza ends against the house, great pains must be taken to have the connection thoroughly flashed with lead.

Fig. 45. Proper Construction for
Piazza Joists

Clapboarding and Siding. Clapboarding is done in sections, from staging lowered successively 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. Clapboards are all quarter-sawed, being cut from the log by a circular saw which cuts always toward the center; they are made 4 feet long, 6 inches wide, and inch thick at the butt. Siding is of similar section but a little thicker, and is commonly sawed in the same way as boards, in lengths of 12 to 16 feet. Either clapboards or siding make a good wall covering; the best should always be quartersawed and laid over a good quality of sheathing paper, which is generally put on in horizontal layers, each layer being lapped

about 2 inches and breaking joints with the paper and flashings already laid.

There are many good brands of paper on the market, with very little to choose between them, the principal qualities required being toughness 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 walls may be exposed 5 or 6 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 thicknesses 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.

LATHING AND PLASTERING

By the time that the clapboarding has been finished the inside of the house must be given over to a new set of mechanics-the lathers. The trade of lathing, although a wood-working trade, is in most localities distinct from the trade of the carpenter, and the lathers will come to the building to put on laths and for nothing else. For this reason it is well for the superintendent to see personally that all of the furring has been completed and completed properly. Walls, ceilings, and soffits should be carefully examined to be sure that their surfaces are true, level, and plumb; chimney breasts and projections of all kinds tried with a square to be certain that all angles are true; corners examined to see that nailings are provided where the laths are to make an angle; and grounds and corner beads set wherever necessary for nailings or for a finish.

Corner Beads. The use of corner beads is a matter of custom, being general in New England and less frequent in the West. In recent years the use of metal corner beads has become common, and they are to be preferred where a sharp corner is desired. Either wood or metal corner beads should be used, as they mean a

saving of time to the plasterer, and, being set and rigidly secured by the carpenter while furring the house, insure a plumb and square corner. The superintendent should see that all beads are in one length, and that they are set plumb and square. Especial attention must be paid to arches, since the perfect shape of the arch is determined by the accuracy of the beads, and it will be difficult to remedy any defects after the plaster has been applied.

Lathing. When the superintendent is satisfied that the rough work has been put in place correctly, the lathers are set to work. It is well to visit the building before much of the lathing has been done, to see that the laths are given the requisite number of nailings

DOOR OPENING

B

Fig. 46. Portion of Partition Showing Method of Lathing

and are spaced properly. Three-eighths of an inch apart is the right width, but there is generally a tendency to put them too near together, in which case the mortar will not press through and form a sufficient key. If the laths are spaced too far apart, the wet mortar will not sustain its own weight. The matter of breaking joints is also of importance, the usual way being

to break joints every sixth course, A, Fig. 46, but a better ceiling is obtained by breaking joints at every lath. Over door and window openings the laths must extend at least to the next stud beyond, to prevent cracking, B, Fig. 46. The direction of the laths must never be changed, and this is a point which will need to be remembered, as there is a great temptation to fill small spaces which occur with laths running diagonally and even at right angles to the other lathing, C, Fig. 46. This must not be allowed, as cracks are sure to appear where the change in direction occurs. The laths themselves should be well seasoned and free from large or black knots, bark, or stains. Bark, which is usually found on the edges, is a serious defect, and any laths showing this should be

pulled off and fresh laths placed, as the bark will invariably cause a stain in the plaster.

Metal Lathing. The use of metal laths is continually increasing and should be encouraged even for wooden houses. This form of lathing holds the plaster more firmly and is not so likely to crack or sag, and it is almost impossible to detach it even if soaked by water. Added to this are the fire-resisting qualities, which render its use advisable for the soffits of stairs in public buildings, under galleries, and over all hot-air pipes enclosed in partitions. Metal laths should always be used where wooden walls connect with brick walls or chimneys; and wherever a solid timber of any size is to be plastered over, a strip of metal lathing covering the timber and lapping well on to the adjoining wooden laths will tend to prevent cracks which would occur if wooden laths only were used. Lathing for exterior plastering should be galvanized or painted, and furred at least inch from the boarding.

Plaster. With the completion of the lathing the house will be ready for the plasterer. Already the mortar will have been mixed, and, piled in large stacks, should have been standing for a week or more. The sand and lime having passed the same scrutiny and tests which we employed when making the mortar for the mason work, the only thing necessary is to see that the mortar is well mixed and tempered and that hair of the proper amount and quality is added at the proper time.

Mixing. For the best results, the lime should be thoroughly slaked at least twenty-four hours before adding the hair, which must be thoroughly beaten up and mixed with the lime paste, and the necessary amount of sand added. This mixture should then be stacked outside of the building as long as possible before being used; for our building, at least ten days. When ready for applying, small quantities of this mixture are wet with water to the proper consistency-tempering, this is called. Unless particular care is taken, the sand and hair will be added as soon as the lime is slaked as it is much more convenient to do; but this should not be allowed, as the lime does not always get wholly slaked and the steam and heat of the slaking lime will burn the hair and destroy its strength. Another practice which should be avoided, is that of mixing the mortar in the basement of the building, for the steam and moisture will pene

trate to all parts of the building at a time when the immediate application of the plaster gives no opportunity for drying off.

With regard to the proportions, about 11⁄2 bushels of hair and 3 barrels of sand to 1 cask of lime is a good ratio, but the amount of sand will in ordinary cases be determined by the judgment of the mixer, who should be a competent and experienced man.

Applying. When the mortar is ready for putting on the laths, we must see that the first or scratch coat is well troweled to push it through the spaces between the laths so as to form a good key. In ordinary two-coat work, this first coat is put on thick enough to come within inch or less of the face of the grounds and beads, as the finish or skim coat is merely a thin veneer of lime putty and fine white sand, troweled and brushed to a hard surface. In three-coat work, the first coat is put on about inch thick, and when somewhat hard it is scratched with diagonal lines nearly through to the laths. As soon as this coat is dry, the second coat is applied and brought to a plane with all angles and corners true and plumb. On large surfaces or in important work this is best done by running screeds, which are strips of mortar 6 to 8 inches wide and 3 or 4 feet apart, carefully laid and leveled and plumbed, with corners and angles made true and brought to the line of the second coat, which is filled in between these upon the scratch coat and brought to a line by running straightedges from screed to screed. Upon this second coat is applied the third or finishing coat, usually either the skim coat used in two-coat work, or a white coat made by mixing plaster of paris and marble dust with the lime putty. If a rougher finish is desired, as for frescoing, a coarse sand in greater quantities may be mixed with the lime putty and floated with a pine or cork-faced float. By consulting the specifications we find that this finish is called for in two-coat work to be left "medium rough".

Screens for Protecting Plaster. Before plastering is begun, the windows must be closed in with screens of cotton cloth tacked upon wooden frames made to fit the window openings. These are not only to protect the plastering from freezing, which completely ruins ordinary lime mortar, but also to prevent the unequal drying of the finished walls, which will occur near the windows in breezy weather. Exterior Plastering. Cement plaster as a covering for exterior walls generally called stucco-is being used to an increasing extent

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