Typical Example of Specifications

"After the concrete has been dumped in place, it is to be slightly rammed, enough only to flush the water to the surface; then it is to be leveled off and allowed to set without being d isturb ed. " The old-fashioned way of mixing concrete was to add so little water that a great deal of ramming was necessary in order to get the water to come to the surface. Of late years the practice has been to mix concrete "very wet," in which case no ramming at all can be done. In walls, in order to obtain a smooth finish, it is often customary to force a spade along the inner surface of the forms so as to bring the mortar and smaller stones to the face, and keep the larger stones away from the face and well within the body of the con crete mass.

"In all cases the concrete is to be mixed, and the parts are to be accurately measured, in the same manner as above described for cement mortar." No method of accurately measuring the parts was given under the specification for cement mortar; hence this specification for concrete is senseless. This is evidently a case of copying from some other specifications without even taking the trouble to study them.

"Concrete not properly mixed will be rejected.

"Concrete Footing.

The footings under all walls, columns, piers, and vault walls are to be made of concrete, of such widths and depths as shown on the drawings.

"All concrete footings are to be laid between plank curbs or sheath-piling, as before specified.

"In all cases the bottoms of the trenches must be approved by the Architect before the footings are laid.

"Concrete Flooring, etc.—The concrete floor ing is to be put down three inches thick, graded and leveled off as may be directed, covering the entire sub-basement floor, including the boiler room, engine rooms, etc., prepared to receive the waterproofing; after the waterproofing has been laid, all is to be concreted 6 inches thick, includ ing the top finish of Portland cement.

"All the above concrete to be of gravel com posed of pebbles varying from inch to 1 inch, four parts; sand, two parts; and Portland ce ment, one part; and top finish of Portland cement 1 inch thick." As this reads, the top finish is to be a layer of pure Portland cement 1 inch thick. This is rather an unusual finish, and the chances that the contractor will put it down as per this specification are very slim indeed. Moreover, it is neither necessary nor advis able to have the finish coat so thick.

"Drain tiles 3 inches diameter laid in broken stone, are to be provided as directed, to drain the space under the sub-basement floor to the cesspool as directed.

"Asphalting and Waterproofing—The mate rials used for waterproofing must be of the very best quality, tarred roofing felt, laid in courses, five-ply; each course is to be cemented with asphalt, applied hot, well mopped; the entire sur face is to be covered with asphalt before the felt is applied, and after the felt has been applied."

A very good specification for meeting ordinary conditions.

"Natural asphalt—Trindad, Seyssel, Sicilian, or other equally good—approved by the Archi tect, entirely free from adulterations, is to be used; to be applied hot in all cases.

"In all cases where asphalt work is jointed, the lap is to be not less than 12 inches. Particu lar care must be taken so that all the work will be perfectly water-tight; necessary precautions are to be taken to prevent lifting and opening of joints, and all the work must be warranted for five years after the completion of the building." A five-year guarantee on this sort of work is likely to prove ineffective, as so many un foreseen things may happen in five years.

"Damp-Proofing—All the walls and piers are to have damp-proof courses connected with the wall and floor waterproofing.

"The parapet walls are to have damp-proof courses as hereinafter specified under the head of 'Slag Roof.' "The Contractor is to build a 4-inch brick wall, laid in Portland cement mortar, on the out side of the stone vault wall of the basement; and the inside of this 4-inch wall is to be asphalted before the stone wall is built. In all cases the waterprobfing of the vault walls is to be con nected with the damp-proof course of floor and sidewalk.

"All damage to the building and machinery on account of leaks, will be made good at the Contractor's expense." This is in form of guarantee that all waterproofing is properly done.

"Stone Masonr.

The exterior vault walls and other walls of the basement and sub-base ment, as indicated on the plans, are to be built of good, sound, selected stone from the excava tion; to be laid in Rosendale cement mortar, ex cept that part below the basement floor, which is to be built with Portland cement mortar; with solid beds and joints between stones of mortar. All to be properly bonded and to be faced on the inside with brick where shown and specified. The inside face is to be built as directed, with recesses; and necessary iron anchors, provided by the Contractor, are to be built in." This is a rather unusual specification, since the excavation was made in solid rock and required blasting. In heavy masonry work, it is commonly specified that no rock shall be used which has been blasted by high explosives, as, after being thrown out by such explosives, there is always a possibility of the rock being injured in the blast. In this case, however, perhaps a very rough rubble wall is intended, in which small pieces of rock may be used, and in which a few shattered pieces would not make any very great differ ence. As a general thing, however, a speci fication allowing the use of such material should be avoided.