A trapezoidal roof profile has a ribbed trapezoidal-shape pattern across the panel. This means, it is a quadrilateral (or a four-sided shape – see Figure 1) that has just a single pair of parallel sides. Sometimes, trapezoidal roofs are mistakenly referred to as corrugated. This is a misnomer as the corrugated profile has a repeating wavy pattern across its surface.Trapezoidal rib roofs are popular with producers because the shape makes them very material-efficient (a high strength-to weight ratio). This makes for a very cost-effective profile. The shadows of the trapezoidal shapes offer clean lines whether installed vertically, diagonally, or horizontally. They also possess good structural characteristics and can carry design loads well (e.g. for snow and wind uplift). However, it is not considered as premium a profile as standing seam due to its attachment method.