Vegetation is the grass or sedum that works best in your climate

Growing medium to support the root system, retain water, and hold the fertilizer

Filter membrane that prevents small soil particles from clogging up the drainage layer

Drainage layer to regulate water retention in the growing medium

Waterproof and root repellent layers to protect the roof structure below

Insulation that improves energy efficiency

Vapour barrier that keeps water vapour from entering the building