Pre-cast Stairway Systems

Pre-cast stairway systems are constructed as follows:
Steel frame is fabricated to accommodate new system. Structural steel shall conform to ASTM A-36 (fy=36,000). All field welds are designed for half stress. All bolts shall conform to A-307 Grade A. Design live load = 100 PSF Max. Treads will be pre-cast, iron rebar reinforced concrete with pebble finish. Maximum variations in height of risers and in the width of treads in any one flight shall be ¼”. Maximum vertical distance between landings shall be 12”0”. All runs to be 11” min. All risers shall be 7” max. Metal is available in black, brown or gray. Installation is completed the same day as old material is removed.