In this country, in recent years, there has been a revival of interest in the architectural details and history of many of the old brick buildings, and it is not infrequent for architects to specify old-style handmade bricks for special work in order faithfully to reproduce the spirit of these older structures. A great deal of literature relating to the history of brick has become available within the last few years, and many of these books are illustrated with beautiful reproductions of noted older buildings.
Modern brickmaking is done by machinery, the clay being ground, mixed with water, and forced through dies to make the required shapes. Some of the modern plants have intricate machinery for actually setting the brick in the kilns, and the finished product is in some localities loaded into large "containers" which are placed on railroad cars, unloaded onto trucks, and delivered at the site with the contents undisturbed.
The manufacturing process of firing bricks calls for temperatures of approximately 1,800° F., applied for from two to three and four days and even longer. This intense heat destroys all combustible materials, and the chemical composition of different clays, so treated, results in a wide range of colors and shades. Browns and reds predominate, but the colors range through grays, creams, buffs, yellows, tans, reds, pinks, and purples. Blues and greens are produced by the addition of chemicals. The textures are varied, being smooth by die finishes, rough by wire cutting, or by sand molding, or by the quality of the clay or shale itself, and there is also a wide use of "clinkered" or "arch" brick which are those slightly distorted or roughened on the face by the action of high heats. Such bricks are used in producing particular architectural effects.
This wide range of shapes, colors, and textures enables brick to be used in the construction of almost any type of building and in such a manner as to make the building harmonize with its surroundings. In recent years the painting of brick by cement paint is of frequent occurrence while an effect of aging is produced by whitewashing the brick, the whitewash being soon affected by the weather.
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An intending builder, before selecting the brick for facing the house, should make certain that the brick will harmonize with the design and that the design will fit its environment. The individual who ordered a "glazed yellow brick for facing a Colonial bungalow" had somewhat scrambled ideas as to architectural requirements.
The selection of a mortar of proper color should also be carefully considered inasmuch as from 10 to 20 per cent of wall surface consists of the mortar. The mortar should harmonize with the color of the brick or properly contrast with it.
Brick masonry must be "bonded" together, that is, the individual brick units must be tied together at certain intervals by bricks laid in the opposite direction - such bricks being called "headers." There are many and varied types of bonding, and any standard work on brick contains full illustrations. Patterns may be easily worked out with brick and many may be found in pamphlets showing the design of brick fireplaces, chimneys, and other details.
Garden walks, steps, and terraces are frequently paved with brick in order to simulate construction usual in the larger Colonial estates, and there is also an increasing use of brick inclosure walls and retaining walls.
The use of salmon brick is recommended in lining chimneys - this because of the fact that these bricks are underburned and therefore will withstand heat action even more than the hard-burned brick. Salmon brick are also recommended as a "backup" material in constructing brick walls as they are more absorbent and therefore tend to absorb such slight moisture as might penetrate through the facing material joints. However, it is better not to try to use salmon brick unless the facing material is distinctly different in color. They should never be exposed directly to the weather, and this has at times occurred when the facing material was of the same color as the salmon brick.
The United States Bureau of Standards (Division of Simplified Practice), in cooperation with the American Institute of Architects and representatives of the brick industry, adopted the following dimensions as the standard of size for both common and face brick: Length, 8 inches; width, 3¾ inches; thickness, 2¼ inches, with permissible variations (plus or minus) of ¼ inch in length and 1/8 inch in width and thickness. These variations are due to the fact that different clays shrink to different degrees according to the amount of heat applied to them.
As with all the other building materials, the principal factor in their satisfactory use in construction is necessarily "workmanship." A perfect building material imperfectly used would give imperfect results. In brick-masonry work when all horizontal and vertical joints are well filled with properly-mixed mortar the wall will give a satisfactory account of itself. Specifications for proper construction may be obtained from the various brick associations.
Roof members should be properly fastened to plates bolted to the tops of the walls according to the directions contained in association brick literature. When window and door frames are put in position the open spaces around them should be filled with mortar and the openings calked with suitable materials so as to prevent moisture penetration. It has happened that when these precautions are not taken water entered the walls at openings, and came through the walls farther away. In both frame and brick construction care should be taken to seal open spaces around the frames.
In case of flat roofs the "flashing" should be of sufficient height and should be carried through the parapet wall which should, preferably, have a coping of vitrified clay.
The danger from fire will be less if the furnace room is walled with brick and if the ceiling (over the furnace) is protected by some fireproof material. Chimneys should always be lined with flue lining and frame members should not be built into chimneys unless 8 inches of solid brick come between the members and the flue proper. This precaution should be taken to prevent a wood member from catching fire from heated gases which may escape from the flue.
All exposed brick walls should be properly furred before being plastered. The use of furring (unless it is of hollow tile) leaves an open air space between the brick walls and the plaster. This air space tends to insulate the house and make it dry and warmer in the winter and cooler in summer. When this air space is open it also would have a tendency to act as a flue in case of fire, so firestops should be inserted at floor levels to prevent the possible passage of flames up this hollow space. The same precaution is advisable in the construction of frame houses. A brick house properly designed and with a fireproof roof is practically immune from catching fire from an adjacent building, and is regarded from an insurance standpoint as the best class of risk.
In considering the heating of a house it should be borne in mind that while brick walls in themselves have a high insulating value, much of the heat losses occur not through the walls themselves but through the window and door openings and by radiation through the window panes.
When construction calls for strong fireproof walls which will have a low maintenance cost and which will not deteriorate in appearance with age, brick naturally suggests itself for consideration, especially since the cost is relatively low, being merely the difference between the cost of frame and brick walls from the tops of foundations to the roof plates, the other items of construction being the same.
A renewed interest is being shown in "reinforced brickwork," the reinforcing being accomplished by inserting metal rods in the wall during the construction, on the same principle that rods are used in reinforced concrete. Investigations of older examples of this construction, and more recent experiments, indicate a wide field of usefulness for reinforced brickwork.
Brick being absolutely fireproof - having a wide range of colors and textures - requiring no upkeep or painting expense, and being of reasonable first cost, naturally suggests itself as a proper construction material for many projects.1