ad. Power Machine Finishing: In lieu of hand fin- ishing, the Contractor has the option of using 4 power machine for finishing concrete floors, provided the machine is approved by the Engineer, The preparation of slab surfaces, or mixing and application of applied top coating, for finishing by machine shall in general be as hereinbefore required for hand finishing. The method of finishing by machine shall conform with the directions of the manufacture. of the power machine. 5-22. TOOLING: &. General Requirements: b. Cement Base: All tooling shall be ac- curately run to true line and square without undue marking of plane surfaces and be left clean cut and burr free, Cement base not otherwise shown, shall be run with 3/4 inch radius cove at floor and 1/8 inch radius bullnose at top edge. c. Exposed Edges of Platforms: Exposed edges of platforms shall be finished with 3/8 inch radius bullnose. d. Curbs, Machinery Foundations and like work shall be finished with 3/8 inch radius outside angles and 3/8 inch radius cove at floors, except as otherwise shown. e. Stairs, except as otherwise indicated, shall have treads pitched forward 1/8 inch, risers pitched forward 1 inch and 3/8 inch radius interior and exterior angles (and treads including tool to within f. landing treads marked with 5-groove marking inches of sides). Scoring: stairs shall be The top surfaces of exterior ramps and lightly scored as detailed on the drawings. g. Marking: Walks, platforms and other surfaces indicated and all cold joints in finished floors shall be marked to true line and square, and to pattern indicated with 1/8 inch radius marking tool. 5-23. CONCRETE FINISH FOR ROOFS: a. Interior surfaces for roofs shall be given a smooth finish as specified under 5-20b. b. Exterior surfaces of roofs to receive roofing shall be tamped, screeded and floated to a reasonably true and smooth surface, and shall then be lightly steel-troweled. ‘5-15