BRICKLAYING, BRICKWORK, the art of building or erecting walls or edifices with bricks, cemented together with mortar, cement, &c. For the materials, &c., used in this business, see the articles BRICK, BRICKLAYER, :MORTAR, TILES, CEMENT, &C.
The first thing to be Itttended to, in bricklaying, is to dig trenches for the foundations, after which the ground must be tried with an iron crow, or rammer, to see that it is sound : if it appear to shake, it must be bored with a well-sinker's tool, in order to ascertain whether the shake be local or general. If the soil prove generally firm, the looser parts, if not very deep, may be dug up till a solid bed be got at, on which a pier or piers may be built, as hereafter described; if the ground be not very loose, it may be made good by ramming into it large stones, close packed together, or dry brick rubbish, of a breadth at the bottom proportioned to the intended insisting weight ; but if the ground be very bad, it must be piled and planked, to ensure the safety of the structure.
In building upon an inclined plane, or rising ground, the foundation ought to rise with the inclination of the ground, in a series of level steps, which will ensure a firm bed fn the courses, and prevent them from sliding, as they would be apt to do if built on inclined planes; and in wet seasons the moisture in the foundation would induce the inclined parts to descend towards the lowest parts, to the manifest danger of fracturing the walls, and destroying the building.
When the ground proves loose to a great depth in places over which it is intended to make windows, doors, or other apertures, while the sides on which the piers must stand are firm, it is a good practice to turn inverted arches under such intended windows, &c. indeed, this is a necessary precau tion in all eases where the depth of wall below the aperture will admit of it. For the small base of the piers will more easily penetrate the ground, than one continued base; and as the piers may be permitted to descend, in a certain degree, so long as they can be kept from spreading, they will carry the arch with them, compressing the ground, and forcing it to reaction against the sides of the inverted arch, which if closely jointed, so far from yielding, will, with the abutting piers, operate as a solid body. Whereas, if this expedient of
inverted arches be not adopted, the low piece of wall under the aperture, not having a sullivient vertical dimension. will give vvws hv the resistance of the ground upon its base, and not only fracture the brickwork between the apertures, but also the N‘indow-sills. it is evident that these arches should be turned with the greatest exactness, and should be in height at least half their width. The parabolic curve will be Mund most effectual in resisting the reaction of the ground ; it being the form most adapted to the laws of unift•m pressure.
The bed of the piers ought to be of equal solidity th•ough out ; fir though the bottom of the trench may be firm enough, yet there be any difference in sul)stance, the settlement will be partial, the amount thereof varying according to the soft ness of the ground ; consequently the piers on the softer ground a ill settle nmre than those on the firmer, and ()evasion a ver nieal fracture in the superstructure.
Should tic solid parts of the trench be found under the intended apertures, and the softer parts where piers are to lie built, the reverse of the above practice must lie resorted to, viz. : build piers on the firm ground, and suspend arches, not inverted. them; ill pe•t'orming which, attention must he paid to the insisting pier, whether it will cover the arch, or not ; lin- if the middle of the pier rest over the middle of the summit of the arch, the narrower the pier is, the greater should be the curvature of the arch of its apex. When sus pended arches are used, the intrados ought to he clear, that the arch may have its full etTect. Here also, as before, the ground on which the piers arc erected should be of equal firmness, lest the building be injured by an unequal settling, which is attended with much more mischievous consequences than where the ground, from being uniformly soft, permits the piers to descend equally, in which ease the building is seldom or never damaged.