third points by diagonal extruded struts extending to third rafter from end. Sill angles shall be anchored to the concrete floor slab by explosive driven coated steel studs or anchor bolts; f. as shown or directed. Erection: 1. Workmanship: All work shall be rigidly and accurately erected to tru line, level, plumb, plane and square in accordance with building manufacturer's directions. Rigid bents shall be assembled as completely as practicable in a horizontal position before being raised into position. 2. Blocks and tackle shall be used as require to pull framed structure into square for installation of roofing sheets. Blocks and tackle shall be strung diagonally across structure approximately every third or fourth frame, with ends secured by passing completely around knees Tackle ends shall not be secured to knee straps. 3. Sheeting: Drift pins may be employed, but not to the extent that elongated holes result from their use. All holes through sheeting shall be completely cover- ed by washers. Contractor shall provide catwalks or planking when installing roofing sheets to avoid walking upon roof surfaces, g@. Doors: Doors as furnished by the building manufacturer shall be of sliding or swing type, and shall consist of extruded frames with corrugated panels riveted to frames. Swing doors shall have aluminum hinges and aluminum cam type latch or cylinder locks. Sliding door operating hardware shall be of aluminum with lintle type trolley tracks, intermediate rub rail and roller guides at the sill. Sliding doors shall be secured by padlocks. Swing and sliding door frames shall consist of extruded sections at jambs only. 2" x 4" blocking of suitable lengt shall be placed at the top and bottom of door openings between door posts to insure proper clearance before bolting posts to eave strut foundation angles. h. Vented Openings: Manufacturer's standard vented openings shall be of the shutter type unglazed. Upper and lower shutters approximately 38 inches by 40 inches shall be provided in each 4 foot bay where vented openings are required by design use. Shutter panels shall be outswinging, hinged at the top and supported each side by collapsible shutter arms. Shutters shall shade or close 13-4