What is the soil depth typically required for an intensive vegetated roof?

An intensive vegetated roof, which supports a wide variety of plants including shrubs and small trees, typically requires a significant depth of soil to accommodate the root systems of these plants. A soil depth of around 12 inches is common because it provides enough volume for proper growth, water retention, and nutrient availability.

This deeper soil layer is essential for intensive gardens, which focus on more complex landscaping and often include heavier planting. In contrast, less extensive vegetated roofs would use a shallower soil depth to support lighter, drought-resistant plants. Therefore, the requirement of 12 inches is appropriate for the intensive nature of the planting scheme involved in this type of green roof.