Ceiling Opening
Opening in the floor slab for the staircase passage.
The ceiling opening — also called the stairwell opening — is the cut-out in the floor slab through which the stair flight passes. Its shape and size largely determine the stair geometry: the width and position of the opening influence headroom, stair width and the possible stair form. The ceiling opening must be precisely planned during the shell construction phase. The visible edge is finished with a ceiling trim.