What defines a flat roof?

A flat roof is characterized as being flat or nearly flat in relation to the horizon. This means that the surface of the roof does not have a significant slope, allowing for a level appearance from a horizontal perspective. Flat roofs are commonly seen in commercial buildings, where they can provide space for HVAC units, solar panels, or rooftop gardens.

The design of flat roofs can pose challenges for draining water, as they don't naturally divert water like pitched roofs do. However, they are often engineered with slight slopes in specific sections to facilitate drainage, but overall, they remain categorized as flat because of their minimal incline. This distinguishes flat roofs from those that are significantly pitched or rounded, which have more pronounced slopes for water runoff and aesthetic purposes.