Because it's a rooftop pool, no digging required - just a 'box' built for the pool. Spa is shown here.
Another view of the spa framed (pool upper left in photo) and ready for rebar.
Pool shown here. Foam is used to waterproof the concrete, not the pool itself (plaster waterproofs the pool). Foam also helps in creating proper depths and provides rigidity for plumbing.
Spa in the foreground showing skimmers in upper corners, drains on the floor. Pool shown in background.
