Tiles installed on roofs with a slope of less than what ratio are considered decorative?

Tiles installed on roofs with a slope of less than a ratio of 2 and 1/2 are considered decorative primarily because they do not provide adequate water-shedding capability for lower sloped roofs. Roofs that have a very gentle slope are at a higher risk for water pooling, which can lead to leaks and structural damage over time. Decorative tiles may serve aesthetic purposes but lack the functional attributes required for long-term protection against the elements in a roofing application.

In the context of roofing codes and practices, the distinction between decorative and functional tiles is critical for ensuring appropriate installation and adherence to building standards. This helps to guide roof design by determining the suitable types of materials based on the slope, ensuring adequate drainage, and promoting roof longevity.