Brick-wall construction, however, involves anehor•rods of various sorts, the ends of which have to he built into the wall by the bricklayer. The walls have also to be corbeled to give a bearing for the floor-joists, and the bricklayer must construct these corbels at the proper places. and bond them firmly to the body of the wall.
lle has also to insert the relieving arches or east-iron or steel beams over windows and door openings, and to set the stone caps and sills, and bond them firmly to the wall. The bonding to gether of the outside walls at corners and of the cross or partition walls to the main walls are other items in the task of the bricklayer. In many building-walls there are introdueed but tresses, panels, diaper-wo•k, moldings, etc.. of a structural or ornamental character, and these have to be executed by the bricklayer to the plans and designs furnished him. Enough has been said to show that bricklaying is much more than the mere placing of one brick on top of another, with a mortar joint between them; it involves a very close adherence to dimensions, position, pattern, and ornament, as specified by the architect, and a knowledge of how to save time and material in securing these require ments. The mode of procedure in laying brick 'piers, chimneys, walls, etc., is practically the same as that in laying walls.
Arch-eonstruction in brickwork requires more particular mention (Figs. 11 and is). When arches are built of common brick, the bricks are laid close together on the inner edges with wedge shaped joints of mortar, but when built of face bricks, the bricks themselves are dressed to wedge-shaped form or to voussoirs and the Dior other tasks besides the plain, solid wall-construc tion so far described, and some of them need to be mentioned to make clear the full extent of the work of the bricklayer. In good building prac tice the walls are tied or anchored to each tloor at intervals of about six feet, by means of tar joints are of uniform thickness. Arches of the construction last described am termed gauged arches. The bond of gauged arches usu ally corresponds to the bond of the wall in which they are set. Arches of common brick are usually built in concent•ic rings, with no bond but the mortar joint between them. Sometimes, however, the rings are bonded together with wedge-shaped courses extending from intrados to extrados. (See Anon.) In laying brick arches the bricklayer makes use of a centre on which to support the arch during construction exactly as is done in laying stone arches, and as previ ousl• described. The mode of procedure is also
the same as in stone arches, the work of setting the arch-bricks beginning at the bottom cn each side, and progressing uniformly upward until the two sides meet at the crown of the arch.
FtaLnaoovING is the process of laying up or applying fireproof materials to beams. cohnnas, etc. (see FIREPROOF CoNsTRUCTI0X.) The more common fireproof materials are burned-elay prod ucts, plaster mixtures. and concrete. Burned-clay fireproofing and fireproofing of plaster mixtures are usually furnished by the manufacturers in molded blocks ready for erection; concrete fire proofing is manufactured on the building-site, and is applied to the member to be protected in a plastic condition and afterwards hardens in place. Floor-construction and column-protection and partitions are the principal classes of fire proofing work. Tile, terra-cotta. and plastic com position blocks for fireproof floors are so made that when laid together they span the space be tween floor-beams and imbed the Leans them selves. Floor-arches are built on centres. as are brick and masonry arches, and by practically the same mode of procedure. To illustrate, a terra cotta floor-arch is made up of two skewbaek blocks, which come next to the beams and are molded so as to tit and enfold them. of a centre block or keyblock, and of several intermediate or haunch blocks. To erect such an arch the mason first suspends a centre of timber between the floor-beams. On this he sets the skewback blocks with a mortar joint between them and the beams. The haunch-blocks are then set. one after another, with mortar joints, working from both ends. and last the keybluck is set. Finally the tops of the blocks are covered with a layer of concrete. Concrete floor-arches are built by sus pending a suitable centre, spreading the concrete in layers and packing it firmly in position where it hardens, after which the centre is removed. Terra-cotta and plastic composition blocks for column-protection are so molded as to fit the column and are laid up with mortar joints much as brickwork is laid. Concrete fireproofing is applied to columns by placing molds around the columns and packing the annular space with con crete which hardens in position. Partition-blocks are laid up with mortar joints exactly like ash lar stonework.