32 BULLETIX 373^ U. S. DEPAETMEISTT OF AGEICULTUEE. 



course, and the joints between the ends of the brick shall not exceed one-eighth 

 (s) inch in width. Joints shall be broken by starting each alternate course 

 with a half brick. Nothing but whole brick shall be used, excepting the half 

 brick for starting alternate courses and pieces of brick for closures, and no 

 piece of brick less than two (2) inches in length shall be used for making a 

 closure. The cutting and trimming of brick shall be done by experienced men, 

 and proper care shall be taken not to check or fracture the part to be used, and 

 the ends of the part used shall be square with its top and sides. 



The brick shall be carried to the bricklayers on pallets or in clamps and not 

 wheeled in barrows. The bricklayers laying the brick shall stand on the brick 

 already laid and shall not in any manner disturb the bedding. No heavy driv- 

 ing will be permitted to straighten courses, and in making closures the pieces 

 of brick shall be so cut that they may be laid in place without driving. Brick 

 shall be laid with the best edge up. Batting for closures shall progress with 

 the laying. 



After the brick are laid they will be carefully inspected, and all those which 

 are soft, cracked, glazed, spalled, overburned, or otherwise imperfect will be 

 marked by the inspector. The contractor shall at once remove such brick from 

 the pavement with flat-nosed tongs, without disturbing the bedding, and shall 

 replace them with approved brick. Kiln-marked and slightly chipped brick, 

 if not otherwise defective, may be turned over and, if the reverse edge is 

 smooth, may remain in the pavement. 



If more than one kind of brick or the brick from more than one plant is fur- 

 nished for the work, each particular kind or make shall be laid in a separate 

 section. 



Rolling hrick. — After the brick have been laid and after all objectionable 

 brick have been removed from the pavement they shall be brought to a true sur- 

 face by means of rolling. The rolling shall be done with a motor or steam 

 tandem roller weighing not less than three (3) and not more than five (5) 

 tons. The pavement shall be rolled in longitudinal and diagonal directions. 

 The longitudinal rolling shall begin at the curbs and progress toward the center 

 of the pavement. The pavement shall then be thoroughly rolled diagonally at 

 an angle of forty-five (45) degrees with the curb. When this rolling has been 

 completed the brick will again be inspected, and all that are broken or dam- 

 aged shall be removed from the pavement and replaced with approved brick. 

 If necessary to secure a uniform surface the brick shall then be again rolled, 

 the roller moving diagonally across the pavement at right angles to the first 

 diagonal rolling. To prevent the brick from being left careened the roller 

 shall in all cases cover exactly the same area in making its backward trip as 

 was covered in its forward trip, and shall proceed at a very slow rate of 

 speed until the entire pavement has received the first rolling. In no event 

 shall the rolling be done when the bedding is in a condition such that the sand 

 or dry mortar will flow up into the joints more than three-eighths (|) inch. 



Filling the joints. — After the brick have been rolled as above specified the 

 joints between them shall be filled with a grout containing equal parts of cement 

 and sand. The grout shall be mixed in a mechanical batch mixer or by hand in 

 batches containing not more than one sack of cement. Hand mixing shall be 

 done in a box about five (5) feet long, thirty (30) inches w^ide, and fourteen 

 (14) inches deep, resting on legs of different lengths, so that the mixture 

 will readily flow to tl:be lowest corner of the box. The sand and cement shall 

 be thoroughly mixed dry. Sufiicient clean water shall then be admixed to 

 produce a grout of a consistency about equal to that of ordinary cream for 

 the first application and of a slightly thicker consistency for subsequent applica- 

 tions. From the time the water is added to the mixture until all of the 



