The two most common structural systems for long span garages are precast concrete (double tees) and post-tensioned concrete. Typical column bay spacings for precast parking garages are 36’, 45’, and 48’, with typical precast double tee widths of 12’ and 15’. Typical column bay spacings for a post-tensioned concrete garage is 24’. The depth of both of these structural systems is approximately 3 feet.
Another structural system is the Filigree Wide Slab (with Dropped Beams) system. Filigree is a combination of precast elements, and cast-in-place concrete topping. It is recommended that the spans be limited to 44’, with an intermediate column at 16’, for a 60’ parking module. Column spacing in the other direction is a function of the number of parking spaces between, such as 20 ft. or 28 ft.