I am faced with replacing/fixing a stairwell for a “walk-down” basement, about 9′ deep. The stairwell is perpendicular to the wall of the house, and is about 4.5 feet wide. It was built approx 35 years ago, with vertical retaining walls, which have slowly tilted inward until they are now constitute a safety hazard.
I would like to build the new stairwell with sloping sidewalls, using the masonry blocks designed for sloping retaining walls. But, I see a problem. Since the wall height varies as the stairs go down, the width of the stairwell opening would also increase as you go toward the house, since there would be more courses of block closer you go to the basement wall, and thus more cumulative setback.
I suppose I’ll have to reproduce the vertical sidewalls, but reinforce it by tieing it to sleeper bars placed alongside the walls, but this approach probably requires a concrete pour with embedded rebar.
Does anyone have any ideas?