ROLLING THE PAVEMENT After all rejected brick have been removed and the pavement has been swept, it is ready for rolling, which should be done with a steam roller weighing from 3 to 6 tons. A very heavy roller is undesirable, at least in the beginning of the rolling, since the first passage of it tilts the brick to one side so much that it is nearly impossible to straighten them up again. The roller should not weigh more than six tons, and four is better. Unless the top faces of the bricks are brought to a plane, the pavement will be rough and noisy, and will lack durability. The bricks should be firmly settled into the sand bed so that traffic may not de press some of the brick, which will make the pavement rough and also make it wear needlessly fast.
The pavement should first be rolled longitudinally, beginning at the crown and working toward the gutter, taking care that each return trip of the roller covers exactly the same area as the preceding trip so that the second passage of the roller may neutralize any careening of the brick due to the first passage. Pavements that have been rolled only once
or always in one direction are very much rougher and more noisy than when properly rolled. If a spot is skipped on the return passage of the roller, it can be detected by a casual inspection of by the noise of a passing vehicle. , The first passage of the roller should be made at a slow speed, not faster than a slow walk, to prevent undue canting of the brick. After the pavement has been rolled longitudinally, roll it back and forth transversely, or at least in both directions at an angle of 45 degrees from curb to curb. The purpose of the rolling is to settle the bricks uniformly into the cushion layer or sand bed. The rolling should not be done with a horse roller, since the horse's feet disturb the position of the loose brick, and also it is impossible to roll the street transversely.