Brick Sidewalks

150. Fig. 150 is easier to lay than Fig. 149, since it is less difficult to maintain the direction of the courses. Possibly there is slightly less danger of stubbing one's toe on a walk laid as in Fig. 149 than on one laid as in Fig. 150. Fig. 151 and 152 show two other rangements of the bricks; but neither of these is as good as either Fig. 149 or Fig. 150, on account of the continuous joints making the displacement of the bricks more likely when wheelbarrows, baggage trucks, or other wheeled vehicles are run over the walk. A pleasing variety is sometimes obtained by introducing different colored bricks, as for example dark-colored and buff bricks.

The side of the walk is usually protected by setting a row of bricks on edge, as shown in Fig. 149-52. Sometimes the bricks are set on end to form a curb, and some manufacturers make a brick block or tile 8 X 8 X 2 inches to be used as curbs for sidewalks.

Laying the Bricks.

On each side of the gravel or cinder foundation should be placed a line of scantlings approximately 2 X 4 inches, whose top edges should accurately conform to the top of the curbs of the finished walk. Between the scantlings is then placed a 2-inch layer of fine clean dry sand upon which to bed the brick. This sand should be spread fairly uniformly with shovels, and then its top surface should be made smooth and uniform and exactly parallel to the surface of the finished walk, by drawing over it a template whose ends run on the scantlings. For several pre cautions applicable in this work, see § 763 and the first and last paragraph of § 764.

After the sand bed has been properly prepared, the bricks are to be laid by men standing upon the brick already in position with out disturbing the sand cushion. Care should be taken to pre serve the direction of the courses and also to secure joints of uni form width, so that there may be neither a needlessly wide joint in closing nor any cutting of the brick. The bricks should be laid with as close joints as possible, for appearance and to prevent as far as possible grass and weeds from growing in the joints.

The surface of the walk should be carefully and thoroughly rammed to settle all the bricks firmly and uniformly into the sand cushion. The ramming may be done with either of the rammers shown in Fig. 138 and Fig. 141, page 527 and 543, respectively. The rammer should be used upon a hard wood plank 2 inches thick, 1 foot wide, and 6 or 8 feet long. Any unevenness of the surface after the walk has been rammed should be corrected by taking up and re-laying the defective area. After the walk has been rammed, the joints are filled with fine dry sand, and a layer about Finch thick is left upon the surface to be further worked into the joints by traffic.

If the earth comes directly against the edge or curb of the sidewalk, it will stick to the bricks when wet, and in drying will contract and pull the bricks away from each other. The cracks

thus formed will fill with dirt, and the process will be repeated the next dry spell, and thus the joints will be gradually widened. This action is entirely prevented by placing 3 or 4 inches of sand between the bricks and the earth.

Some cities use a concrete curb at the edge of the brick walk. This curb is sometimes 2 X 8 inches, and sometimes 6 X 6 inches. The cost of a concrete curb is hardly justifiable, since the chief advantage of it is obtained by the use of sand as described in the preceding paragraph.

If the center of the walk is above the surrounding surface and particularly if it is on an embankment, there should be considerable earth against the sides of the walk to prevent the expansion of water freezing in the joints from crowding the curbs out and increasing the width of the joints.

Transverse Slope.

A brick sidewalk should be laid with a slope toward the street of or an inch to the foot, to secure surface drainage. Not infrequently brick sidewalks bounded by grass plats on both sides are laid with the two sides on the same level, and the center is raised an inch or more. This practice is undesirable, since the gutter formed at each side of the walk be comes a channel to carry the water longitudinally along the walk, whereas the water should be permitted to flow across the walk into the street gutter. Occasionally the crown is made so great as to confine the travel to the center.

Brick Crossings on Unpaved Street.

These are usually laid substantially as a two-course brick pavement. The subgrade is excavated to a depth of 14 to 16 inches, according to the char acter of the soil and the volume of the traffic, below the top of the finished crossing. The foundation should be excavated, say, 6 inches wider on each side than it is proposed to lay the bricks, in order that there may be a shoulder or footing to support the outer brick; and the edges of the foundation should have a crown of, say, 6 inches, most of which should be at the edge so that the finished crossing may have a slope at the sides that will be easy for vehicle wheels to mount. After the soil has been tamped to consolidate it and to reveal any soft place, a layer of gravel or cinders 6 to 8 inches thick is then laid and tamped. Upon this foundation is placed a layer of hard-burned building bricks laid flatwise. The joints of the lower course of bricks is swept full of fine sand, and a cushion coat of 2 inches of sand is left upon the brick. The top surface of the sand cushion should be brought parallel to the finished surface of the proposed crossing, by the use of a lute or hand scraper. The sand cushion is then covered with very hard-burned building brick or with rejected paving bricks or blocks, set on edge and properly breaking joints. These bricks are then thoroughly rammed, and the joints are swept full of fine sand.