Swallowtail cold plunge, per architect plan dated 2026-09-25: two 10" treads (architect's third tread removed), side bench at step-2 depth, 48" footwell, square inside corners. Fully grouted, reinforced 8" CMU shell (replaces the drawn concrete walls), cast-in-place steps, bonded waterproofing, tile. Wall-face suction channel, step-riser returns, cedar roll-up cover parking on a shelf behind the suction wall.
Drag to orbit, pinch or scroll to zoom. Cutaway removes the near wall so you can see the treads, the side bench and the footwell.
Finished interior dimensions. Walls under the coping shown dashed. Cut lines A and B key to sheet A2.
Section A runs down the steps to the footwell toward the suction wall. Section B cuts across the footwell and side bench looking at the channel grate.
Enlarged from Section A. Rebar shown is sized on sheet A5 — the engineer of record sets final sizes and spacing.
The cover rolls away from the steps and parks on the floor behind the suction wall. Slats ride on a rebated lip along both side walls so the cover sits flush with the coping.
A first-pass strength check of the plunge wall as a fully grouted, reinforced 8" CMU cantilever fixed at the slab, per TMS 402 strength design. Two governing cases: plunge full with nothing outside, and plunge empty with backfill against the wall. Adjust the inputs and the check updates.