These leave-outs should be filled in after the panels are properly placed. In areas where the finished floor will be exposed concrete, or must be especially smooth, it is advisable to consider a topping layer. If the lowest level is a structured slab, casting beds can be provided in the crawl space within the building perimeter, or in areas immediately adjacent to the building footprint. It is always good to limit the travel distance of a panel from its casting bed to its final location due to associated labor and equipment costs. It may be necessary to have casting beds outside when there is not be enough slab area available for all panels to be constructed simultaneously.
Steel can be advantageous if a prime objective is speed of erection.
Placing a steel mill order early alleviates delays. This requires significant coordination efforts early in the design process. A client may decide to authorize placement of a mill order prior to awarding the construction contract to a specific general contractor but this must be done with caution. If the structural frame is steel, the contractor can consider whether or not it makes sense to erect the steel prior to erecting the tilt-wall panels. Erecting steel first could eliminate the need for exterior bracing but it would likely preclude use of the floor slab as the base for casting beds.