Most tilt-up contractors face the problem of casting wall panels with a total area that exceeds the footprint (ground floor area) of the building. For a four-story warehouse near Seattle, the available footprint was less than half the total square footage of the walls. Still, the architect chose tilt-up.

CONSTRUCTION PLANNING

The architect, contractor, and subcontractors held meetings about 5 weeks before the project start. They addressed: crane size, dowel and reinforcing steel placement, forming techniques, placing and finishing, wall panel layout, wall panel lifting sequence, wall panel bracing, and access for the structural steel subcontractor.

DESIGN OF THE STACK CASTING FORMS

Using plywood panels for the side forms of each stack made the order of construction easier. The design called for a treated 4x8 at the top of each panel. A 2x8 plank was used for the bottom.

REINFORCING STEEL AND SCREEDING CONSIDERATIONS

The large wall panels required a lot of reinforcing steel. The reinforcing consisted of top and bottom mats, dictating an external screeding system for the panels.