28 BULLETIN 246, U. S. DEPARTMENT OF AGRICULTURE. 



grade and to the required cross section. The rolling shall be done with a hand 

 roller not less than twenty-four (24) inches in diameter, not less than twenty- 

 four (24) inches in width, and weighing not less than ten (10) pounds per inch 

 in width. 



Laying brick. — Upon the sand cushion, prepared as above described, the brick 

 shall be laid on edge from curb to curb in straight courses at right angles to 

 the curb, with the lug sides all in the same direction. The brick shall be laid 

 so that the lugs of the brick in one course will touch the brick in the adjoin- 

 ing course, and the joints between the ends of the brick shall not exceed 

 one-eighth (i) 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 sand cushion. No heavy 

 driving 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 sand cushion, aud 

 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 brick. — 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 and thoroughly bedded ou the sand cushion by means of rolling. The roiling 

 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, and shall be continued until the 

 brick are well bedded on the sand cushion. The pavement shall then be thor- 

 oughly rolled diagonally :it an angle of forty-five (45) degrees with the curb. 

 When this rolling has been completed the brick will again be inspected, and nil 

 that are broken or damaged shall be removed from the pavement and replaced 

 with approved brick. 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 eases cover 

 exactly the same area in making its backward trip as was covered in its for- 

 ward trip, and shall proceed at a very slow rate of speed until the entire pave- 

 ment has received the first rolling. In no event shall the rolling be done when 

 the sand cushion is in a condition such that the sand will flow up into the 

 joints more than three-eights (f) 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 



