What is the primary design characteristic of a flat roof?

The primary design characteristic of a flat roof is the minimal slope for drainage. Flat roofs are designed with a slight pitch to ensure that water can run off instead of pooling on the surface. This minimal slope helps to prevent water accumulation, which can lead to leaks and structural damage over time. Having a flat profile allows for various uses of the rooftop space, such as creating terraces or installing mechanical equipment, while still effectively managing water drainage through integrated gutter and drainage systems. This design is particularly common in commercial buildings and can also be seen in some residential structures, making it an efficient choice for various architectural applications.