BRICKLAYING is the process of laying up or joining together brickwork. Brickwork in build ing includes piers, walls, arches, vaults, chim neys, fireplaces. and various ornamental details and trimmings. No material except wood is so extensively used in building as brick. Bricks are made from clap and sand formed in molds and burned in kilns: they are produced in a great variety of shapes, sizes, colors, and styles suitable for the numerous purposes to which they are put in building construction. (See liaterc.) With the exception of arches, the process of bricklaying is practically the same for all kinds of brickwork used in building. It will be unnecessary, therefore, to consider separately walls, vaults, chimneys, etc., as enumerated above. To build any kind of a brick structure so as to make it a strong and durable piece of work, it is necessary to have a bed of some kind of mortar between the bricks. Brickwork, therefore, consists both of mortar and bricks. The majority of brick buildings are built with common lime mortar, to which natural cement is sometimes added. For brickwork below ground. hydraulic lime or cement mortar is used. In brickwork of common brick, the thick ness of the mortar joints is from 3-16 of an inch to 3-3 of an inch. and every void in the work not occupied by other materials is filled with mortar.
The usual way to specify the thickness of joint in brickwork of common brick is by the height of eight courses of the brick measured in the wall; this height should not exceed by more than 2 inches the height of eight courses of the same brick laid dry. As common bricks are usually quite rough and uneven, it is not always easy to determine the thickness of a single joint: hence the larger unit of measure furnished by eight bricks is employed. Pressed bricks being smooth and true. enables the thickness of single joints to be specified. This is usually one-eighth inch. The methods of bricklaying for all kinds of brickwork except arches and trimmings can be illustrated by describing wall-construetion. A brick wall consists of two outside courses, joined together by one or more interior courses or fill ing courses. The usual method of construction is to lay the outside courses first. The most ap proved procedure in laying an outside course of bricks is as follows: The bricklayer first spreads mortar with a trowel along a bed for the brick, and also scrapes a dab of mortar against the outer vertical angle of the last brick laid. Ile
then presses the brick into its place with a sliding motion, which forces the mortar to fill the joints completely. Having continued the two outer courses of brick to an angle or opening, the next task is to fill the space between them or to lay the filling courses. This is clone by filling the space with a thick bed of soft mortar and press ing the bricks into this mortar with a downward diagonal motion, termed 'shoving,' so as to press the mortar up into the joints. By a repe tition of the process described, the wall is con structed, except that, if the face of the wall is to he plastered, the mortar projecting from the face-joints is scraped out flush with the brick: or, if the wall is to be exposed, the joints are `struck' by holding the trowel obliquely and cut ting out the joint, so that the mortar has a slant like a roof to shed water.
The face-briek are often laid in a mortar of lime paste and dry, fine sand, colored with some pigment. Frequently. also, the face-joints are pointed. The tilling courses are sometimes laid dry on a bed of mortar. and the vertical joints poured full of grout or thin liquid mortar. The arrangement or 'bond' of the brick in the outside courses of walls is determined by current prac tiee or by the specifications of the arehilect. There are several bonds in common use, which differ chiefly in the different arrangement of the headers and stretchers. A header in brick ma sonry is a brick set so that its end is exposed; a stretcher is a brick set so that its side is ex posed. It will be plain that a brick laid as a header projects back into the filling, and acts as an anchor bond to bind together the outside courses and the filling courses. When a course of headers is laid between every four or six courses of stretchers, the bond is known as common bond (Fig. S). English bond (Fig. 9) consists of alternate courses of headers and stretchers, and Flemish bond ( Fig. 10) consists of alternate headers and stretchers in each course. There are several other varieties of bonds, but those named are the most common. Whatever the bond chosen may be, the method of laying the brick is that described above.