Wooden cornices, when used on brick or stone buildings, are built in practically the same way as on wooden buildings, except that in brick buildings it is frequently necessary to build plank brackets, or "lookouts," into the wall to support the woodwork. Ordinarily, on brick dwellings, the wall facia comes down but 1 or 2 inches on to the brickwork and is nailed to the plate, but occasionally it is desirable to cover up a foot or more of brickwork, as in Figs. 137 and 139, in which case it is necessary to build nailing strips into the wall at the proper height to hold the finish.
The varieties of cornice construction are innumerable, and their shape is more a matter of taste than of construction, the gutter, as has already been stated, being the principal constructive feature. As an aid to the architect in deciding upon the style of cornice to be adopted, and in detailing the same, a number of details are given of various styles of cornices, which, with those already referred to, may be considered as covering every type of wooden cornice.
Figs. 137-141 show various styles of box cornices, i. e, those in which the supporting timbers are concealed.
Fig. 137 shows the manner in which a classical cornice like that shown in Fig. 138 is generally constructed. The finish, and also the gutter, is nailed to plank lookouts built into the wall about every 24 inches. With wooden walls these lookouts are spiked to the side of the studding. The shape of the mouldings may be varied to suit individual taste, but the pieces should be put together about as shown, and a drip should always be provided at the point D. The bottom of the gutter should be inclined toward the outlets, and the tin should be carried well 'up on the roof, as shown. When the gutter is surmounted by a balustrade especial pains must be taken in tinning about the posts, and the bottom rail of the balustrade should be kept at least 2 inches above the roof.
In the Northern States snow is quite sure to lie back of such balustrades, and the roof should be tinned for a considerable distance behind the railing, as shown in the figure.
Fig. 139 shows a section of the cornice of the Burnham Athenaeum, Champaign, l11s, Mr. J. A. Schweinfurth, architect. The soffit of the cornice is paneled and the brackets are spaced from 2 to 3 feet apart. This makes a very suitable cornice for a classical building with a low pitch roof.
Fig. 140 shows a common method of forming a wooden cornice at the base of a Mansard or gambrel roof, where the walls are of brick. The double gutter shown has already been described, and should always be used on such cornices. The wall plate should, of course, be bolted to the wall in the manner shown in Fig. 139.
Fig. 141 shows a box cornice used by the author on a brick city residence in Denver, Col. A stone or terra cotta cornice would have been more appropriate, but could not be afforded. The gutter is the same in construction as that shown in Fig. 140, the crown moulding being level, while the bottom of the gutter has a fall of about 1 inch.
Fig. 142 shows a section of the cornice on a grammar school building designed for the city of Boston by Mr. E. M. Wheelwright. The especial feature of this cornice is the manner in which the rafter ends are supported, it being in this respect rather unique. Usually the rafter ends are made self-supporting, as cantilevers, and in this case the only necessity for the lower brackets and beam is to satisfy the eye rather than to support the rafter ends. For a heavy building, however, such a cornice seems very effective, and would probably stand longer in case of lire.
Open wooden cornices, i. e., those in which the rafter ends are exposed, appear to be very popular at the present time, and they certainly make the best construction, both in durability and safety from fire.
Elaborate cornices generally have the rafter ends made of white or Southern pine, dressed for painting or varnishing and spaced at regular intervals. They are supported on the wall plate and by spiking their upper ends to the common rafters or to planks cut between. The roof boarding over the projection must be of sufficient thickness that the shingle or slate nails will not go through. A covering of 1 ¾-inch planks matched and beaded is undoubtedly the best, as it affords a good " hold " for the nails and is slow burning. On dwellings, however, it is more common to cover the rafter ends with ¾-inch white or Southern pine ceiling, dressed side down, with the usual roof boarding or sheathing laid on top. A single thickness of -7/8-inch ceiling is hardly sufficient to make a good job, although it has been used for shingled roofs. The rafter ends are generally sawn to a pattern, and they have a better appearance when 3 or 4 inches thick. Fig. 143, from a house at Germantown, Pa., Frank Miles Day & Bro., architects, shows rather an unusual method of forming the gutter in an open cornice, with a tile roof. The idea was evidently to conceal the gutter and permit of a thin edge to the roof. As shown in the elevation, a portion of each tile was placed across the gutter, and, aside from the looks, the author would regard this as a very important precaution, as these tiles will prevent snow from lodging in the gutter, while without them such a gutter would be likely to fill solid with snow and ice.
1l6. Conductors. - The pipes which conduct the water from the gutter to the ground or drain are variously termed "conductors," "leaders" or "down-spouts," the first term probably being in most general use.
In the New England States, and possibly in some others, wooden conductors are often used on dwellings, but in most localities metal conductors alone are used.
The wooden conductors used in New England are made of two semi-cylinders of wood, about \ inch thick, grooved and splined at the edges. These semi-cylinders are cut from the hollow portion of wooden gutters, so that the material practically costs but little. They are made of white pine or cypress, the latter wood being far the more durable, and from 1 ½ inches to 3 inches inside diameter. They are usually painted the same color as the trimmings of the house. Fig. 144 shows a patented section, made in Boston, of three pieces, with wall iron attached. Except for the danger of being split by the water choking up and freezing, cypress gutters are fully as durable as galvanized iron pipes, and much more durable than tin pipes. These conductors may be finished at the top by a wooden moulding, turned in two parts and nailed to the pipe ; at the bottom they are usually cut off square about 12 inches above the ground. If they are to be connected with the drain, the lower end may be inserted in a piece of iron soil pipe.
Metal conductors are usually made of galvanized iron, although tin is sometimes used on buildings of very moderate cost, and copper on public buildings and the best class of private buildings.
Tin conductors are soon eaten through by rust and are not at all economical in the long run ; they are also easily dented.
Copper is the most durable of all materials and should be used when the rest of the construction will warrant the expense.
Galvanized iron, however, makes a very durable conductor, when kept painted, and if made of suitable thickness is not easily dented. For ordinary conditions No. 27 iron is sufficiently heavy, but where the pipe is exposed to hard usage, No. 20 or No. 22 iron should be used.* Copper conductors are usually made of either 14-ounce or
Fig. 144. - Steam's Patent Cypres Conductor and Malleable Wall Irons.
16-ounce cold rolled copper. With both metals the joints should be both soldered and riveted. Metal conductors may be round, octagon or rectangular in section, but should contain some provision for expansion in case of freezing solid, as often happens. A corrugated round pipe makes an excellent conductor and the square or octagon shapes permit of some expansion, but a plain round pipe permits of none. Corrugated round and rectangular pipes are carried in stock in many cities, but it costs but little more to have the pipes made to order, and many metal workers make their own conductor pipes. When made to order they may of course be moulded to suit the taste of the architect. The section at A, Fig. 145, shows quite a common section for custom-made pipes, while the section at 2? is the stock pattern. Rectangular conductors generally look better than round ones, and are hence more often used where a fine appearance is desired.
*The thickness of all sheet iron and steel is measured by the United States Standard Gauge; in Appendix.
The stock sizes for metal conductors are 2, 3, 4, 5 and 6 inches for round pipes, and 17/8x2 7/8, 2½x3 7/8, 3 1/8x4¾ and 3 ¾x5 ¾ inches for corrugated rectangular pipes. Special pipes may be made of any size.
On good work metal conductors are usually finished at the top with ornamental caps, which may be made of various shapes, a common one being shown in Fig. 146.
Conductors should be secured to the wall by malleable iron fittings made for the purpose ; these are usually driven or screwed into the wall about 5 feet apart, and screwed to a wooden conductor, or wired to a metal one.
Goose-Necks. - The connection between a wooden conductor and, the gutter is usually made by a lead pipe, called a "gooseneck," from its often being bent to that shape. For 3-inch conductors 2½-inch pipe should be used, and for 4-inch conductors 3-inch pipe. Lead goose-necks are occasionally used with metal conductors, but more often a piece of pipe, either straight or curved, is used to make the connection; in fact the author has never seen a lead "goose-neck" in the West. When the conductors have ornamental caps the connecting pipe is merely placed inside of the cap. The goose-neck or pipe should be soldered to a tin or metal gutter - generally a short piece of pipe is soldered to the gutter, and the connecting pipe slipped over it.
Waste from Conductors. - Wherever possible the conductors should be connected with the sewer by means of earthenware drain pipes, laid below the frost line and securely trapped. The trap should also be provided with a clean-out buildings are usually finished to correspond with the eaves. If the eaves have a close finish, a similar finish is carried up "on the rake" of the gables. When a box finish is used for the eaves, the "raking cornice" is usually boxed out to correspond. Rake mouldings of the same section as the eave mouldings will not mitre at the intersection (i, e., if the eave mouldings are plumb), and to make a proper intersection the rake moulding should be worked to fit the eave moulding, as shown in Fig. 148.
When the conductors cannot be connected with the sewer, dry wells filled with stones may be sunk 10 to 20 feet from the building and drains laid to these.
On isolated dwellings, troughs of stone, cement or wood, laid above the ground, may be used to carry the water away from the walls, but in no case should the water from the conductors be allowed to run down on the foundation walls. 117. Conductors Carried Inside the Walls. - It is often desirable and sometimes necessary to place the conductors on the inside of the wall. In such cases 4-inch cast iron soil pipe should be used (cast iron does not rust or corrode as badly as wrought iron) with joints caulked and soldered. Especial pains should also be taken to protect the pipes from frost, and if possible they should be perfectly straight and perpendicular. When practicable it is a good idea to fur the outer wall so that the conductor may be kept entirely inside of the wall line ; when this is not practicable, a recess should be left in the wall for the pipe, but there should never be less than 9 inches of wall between the pipes and the outer air, and it is advisable that the space around the pipe be packed with mineral wool. When the building is heated by steam, a steam pipe may either be run up beside the conductor, or a Y may be placed in the conductor in the cellar and a steam pipe connected with it.
The upper end of the conductor should always be protected by a galvanized wire screen, to keep out leaves and other solid substances, and, where practicable, a hand hole should he provided near the top. Fig. 147 shows a detail for an inside conductor in a building designed by Frederick W. Perkins, architect.
1l8. Gable Finish. - The gable ends of the roof on wooden.
The rake moulding is obtained by drawing lines parallel to the pitch of the roof from the angles of the eave moulding, and making the projection A', B', etc., of the same length as the corresponding projections of the eave mould.
A moulding obtained in this way will not make a true mitre, but it is the best that can be done. When the eave moulding is set at right angles to the roof, as shown in Fig. 153, a rake moulding of the same section will mitre perfectly. A moulding set in that way, however, does not look as well as when vertical.
In classical buildings, the cornice, with the exception of the crown mould, is always carried across the end of the building, and the raking cornice finishes on top of it. In Colonial work, and particularly on buildings with a gambrel roof, the cornice was often returned a short distance, at the gable ends, to make a stop for the gable finish, as shown in Fig. 149, and this method is still often followed.
The correct method of returning the cornice under a gable is that shown at A, but the method shown at B is more often adopted on wooden buildings. The top of the return should be set on a bevel and covered with metal.
Fig. 149 B.
The gable finish when boxed is supported by spiking lookouts, 2 or 3 feet apart to the wall, and nailing a plank to their outer ends, as shown in Figs. 153 and 154a. The roof boarding and mouldings are then nailed to the outer plank, and the planceer or soffit is nailed to the under side of the lookouts.
When the eaves are finished with the rafter ends exposed, the gable ends are usually finished either with ornamentalrafters, projecting 16 or more inches from the wall, as in Fig. 150, or by verge boards. The ornamental rafters may be supported by heavy brackets at the bottom, and by the ridge at the top, or by lookouts; generally
Verge boards are applied and supported in many ways, some of the more common being shown in Figs, 151-155. With open eaves the verge boards are generally, although not always, supported at their lower end by wooden brackets, which also serve to stop the gable mouldings, or belt courses, as shown in Figs. 150 and 152, the bracket being used more to stop the gable finish than for an actual support.
With an eaves finish like that shown at A, Fig. 153, with the soffit of the eaves and raking cornice in the same plane, the verge board may be supported as shown in Section C without brackets, in which case the belt courses on the gable, if any, should be placed above the point E, unless they are to be carried around the sides of the building. The wall under the soffit should be finished with a board to correspond with the fascia under the eaves. The projection of verge boards is seldom less than 14 inches.
Fig. 154 shows a rather peculiar method of stopping the verge boards, with close eaves; a ledge or shelf being formed to close the lower end, as shown in the enlarged detail, Fig. 154a, and the eave mouldings being returned under it, to form a belt course. Fig. 155 shows a very similar construction used in connection with a horizontal soffit to the eaves; in this case it is the only suitable method of stopping the verge board. The top of the ledges or shelves shown in these figures should be pitched outward and covered with tin or zinc.
On brick and stone buildings of a public or enduring character, and on all city buildings, the gable walls are generally carried above the roof and coped with stone or terra cotta, but on dwellings not within the fire limits the gables are usually finished the same as on wooden buildings, the lookouts which support the raking cornice being built into the brick or stonework. Wooden cornices are much cheaper than stone or terra cotta cornices or coping, and on suburban residences they seem more appropriate and are sufficiently durable. A plank should be bolted to the top of the wall to receive the sheathing and to stay the wall. If the finish is very deep it will also be necessary to build bond timbers or wooden bricks into the wall at intervals to nail the finish to.