Concrete walls, where of the right texture and color, such as that made from coquina in Florida, give a pleasing effect.
Roof coverings comprise tin, copper, slag, tiles, slate and shingles, each having its own appropriateness. Copper is the only permanent one of those mentioned, and slag is the next best. Tiles and slate require constant repairs, and shingles rarely last more than 20 years. Shingles lend themselves admirably to staining, and are deservedly popular. Thatch is attempted where picturesqueness is demanded.
A roof interesting from the constructive standpoint is that commonly used on the steel skeleton building. It is known as actinolite, and consists of a number of thicknesses of heavy felts bedded upon a smooth Portland-cement surface, and covered with a roofing cement on ,which are laid vitrified tiles with the joints thoroughly filled, practically forming a pave ment.
Interior Finishes.— For ordinary buildings the interior finish of floors, walls and ceilings must necessarily be simple, consisting of cement or wood for the floors and plaster for the walls and ceilings, except that in the case of mill con struction walls are usually made of hard red brick, pointed inside the same as outside, and ceilings consist of the dressed undersurface of the floor planking white-washed, painted or varnished.
Cemented floors are the most permanent, par ticularly where they are subjected to moisture, although the hard pine and maple flooring com monly used is less tiresome to walk on and is sufficiently durable.
The so-called patent plasters have come largely into use by reason of their hardness and quick-setting quality. They are mixed by machifie in fixed proportions, and are therefore more dependable in quality than the ordinary lime mortar. If applied to lath, the patent plas ters require that the lath, if of wood, shall be wet before application, or, if of metal, that the metal be of heavy threads, as the finer wire cloth is sometimes eaten away by the ingredients of the plaster.
Tiles, whether of marble, ceramic or glass, form excellent interior finishes, except that small tiles for floors are likely to loosen, and frequent joints in tiling become unsightly through discoloration. The glass tile known as topalite° produces a finish similar to enameled brick, and has been shown in some cases to be more lasting. Interlocking rubber tiles are de sirable in cases where there is risk of slipping, such as for elevator floors. They are also good deadeners of sound.
Beautiful effects of mosaic, both of marble and of glass, are easily obtainable — a great variety of- color and design is largely in their favor. All of these applied finishes require a solid base, preferably of masonry or concrete.
The variety of woods for interior finish is almost without limit, and has been greatly in creased by staining and by methods of finish.
In no department of interior ornamentation has greater progress been made than in plaster work— a system which can he pushed to almost any point of elaboration, and which lends itself perfectly to painted decoration. In fact, there are few materials that cannot be simulated in plaster if the decoration is clever.
The field of interior decoration was never wider, and the knowledge of the application of leathers, stamped, modeled and woven fab rics, and the thousand and one other forms of wall applications, never better understood.
In marble for interior use America is not particularly fortunate. Granite and limestone produce satisfactory results, but most of the American marbles are cold and lacking in rich ness of texture. Among the best marbles are the Knoxville Gray, and a few of the whites. For the more beautiful effects recourse must be had to the imported marbles, such as Sienna, Numidian, Pavonnezza, Alps Green and others. See BUILDING LAWS; BUILDING MATERIALS; CITY PLANNING; IRON SKELETON CONSTRUC TION ; STRENGTH OF MATERIALS.