SPEOIFIOATIONS FOR BRICK MASONRY. For Buildings. There is not even a remote approach to uniformity in the specifica tions for the brick-work of buildings. Ordinarily the specifications for the brick masonry are very brief and incomplete. The following conform closely to ordinary construction. Of course, a higher grade of workmanship can be obtained by more stringent specifications.
The brick in the exterior walls must be of good quality, hard-burned; fine, compact, and uniform in texture; regular in shape, and uniform in size. One fourth of the brick in the interior walls may be what is known as soft or salmon brick. The brick must be thoroughly wet before being laid. The joints of the exterior walls shall be from } to } inch thick.t The joints of interior division walls may be from } to } inch thick. The mortar shall be composed of 1 part of fresh, well-slacked lime and 2} to 3 parts of clean, sharp sand.$ The lime paste and the sand shall be thoroughly mixed before using. The joints shall be well filled with the above mortar; and no grout shall be used in the work. The bond must consist of five courses of stretchers to one of headers, and shall be so arranged as to thoroughly bind the exterior and interior portions of the wall to each other.
The contractor must furnish, set up, and take away his own scaffolding; he must build in such strips, plugs, blocks, scantling, etc., as are required for securing the wood-work; and must also assist in placing all iron-work, as beams, stairways, anchors, bed-plates, etc., connected with the brick-work.
For Sewers. The following are the specifications employed in the construction of brick sewers in Washington, D. C.: "The best quality of whole new brick, burned hard entirely through, free from injurious cracks, with true even faces, and with a crushing strength of not less than 5,000 pounds per square inch, shall be used, and must be thoroughly wet by immersion immediately before laying. Every brick is required to be
laid in full mortar joints, on bottom, sides, and ends, which for each brick is to be performed by one operation. In no case is the joint to be made by working in mortar after the brick has been laid. Every second course shall be laid with a line, and joints shall not exceed three eighths of an inch. The brick-work of the arches shall be properly bonded, and keyed as directed by the engineer. No portion of the brick-work shall be laid dry and afterwards grouted.
"The mortar shall be composed of cement and dry sand, in the proportion of 300 pounds of cement and 2 barrels of loose sand, thoroughly mixed dry, and a sufficient quantity of water afterwards added to form a rather stiff paste. It shall be used within an hour after mixing, and not at all if once set.
"The cement shall conform to the standard specification of the American Society for Testing Materials.
"The sand used shall be clean, sharp, free from loam, vegetable matter, or other dirt, and capable of giving the standard results with the cement. "The water shall be fresh, and clean, free from earth, dirt, or sewage.
"Tight mortar-boxes shall be provided by the contractor, and no mortar shall be made except in such boxes.
"The proportions given are intended to form a mortar in which every particle of sand shall be enveloped by the cement; and this result must be attained to the satisfaction of the engineer and under his direction. The thorough mixing and incorporation of all materials (preferably by machine labor) will be insisted upon. If by hand labor, the dry cement and sand shall be turned over with shovels by skilled workmen not less than six times before the water is added. After adding the water, the paste shall again be turned over and mixed with shovels by skilled workmen not less than three times before it is used." •