Abstract: A system for establishing modular concrete truss stairway during construction of a multi-floor building having concrete decks provides two pre-cast concrete stringers of plural stairsteps and a cast-in-place intermediate landing therebetween forming a stair truss structurally attached to and communicating between two vertically spaced adjacent concrete decks. The intermediate concrete landing is carried between the adjacent vertically spaced decks by adjacent end portions of the stringers. Internal reinforcement in the concrete decks, in each stringer and in the intermediate landing is operatively interconnected to provide structural rigidity to the stair truss. Concurrent pouring of concrete for the upper deck, the intermediate landing and a blocked out area defined in a lower deck structurally attaches the stair truss therebetween providing an operative stairway upon hardening of the concrete.

Abstract: A system for establishing modular concrete truss stairway during construction of a multi-floor building having concrete decks provides two pre-cast concrete stringers of plural stairsteps and a cast-in-place intermediate landing therebetween forming a stair truss structurally attached to and communicating between two vertically spaced adjacent concrete decks. The intermediate concrete landing is carried between the adjacent vertically spaced decks by adjacent end portions of the stringers. Internal reinforcement in the concrete decks, in each stringer and in the intermediate landing is operatively interconnected to provide structural rigidity to the stair truss. Concurrent pouring of concrete for the upper deck, the intermediate landing and a blocked out area defined in a lower deck structurally attaches the stair truss therebetween providing an operative stairway upon hardening of the concrete.