The advent of more environmentally conscious building designs in recent years has prompted owners, architects, engineers, designers, Green Roofdevelopers and others to elevate the urban landscape to the rooftops of their buildings. The benefits of lowering the urban heat island and improved HVAC efficiency need to be balanced with the increased load of a “garden in the air.” The other problem is how to keep this esthetically pleasing feature perpetually alive and well through all the seasons.
When the horticultural community was presented with this problem, they turned to expanded shale, clay and slate (ESCS) as a component of the soil mix. This unique material satisfies several requirements for optimizing the growing medium but since it is about one half the density of natural soil it also satisfies the need to reduce the dead load for a rooftop garden or greenroof. ESCS, with its interstitial voids, acts as tiny reservoirs for moisture in the soil blend. This moisture is readily available to the rooftop plant life, but will not contribute to root rot. And the high cationic exchange rate of the material makes it ideal for the release of nutrients for the plant root network.
ESCS is formed from natural raw materials under exposure to a high temperature process that creates a unique ceramic product that will not deteriorate over time. When blended into a soil matrix for greenroof construction it will essentially outlive the life of the building.
Landscapers, garden centers, nurseries, and horticulturalist have known the benefits of ESCS for several years. Now that the plant life has been elevated to the rooftops, ESCS has naturally aided in the transition. If you are going to put your plants on the roof, you want to ensure that the system will last and perform with little maintenance over the life of the building without adding unnecessary costs to the building design. Expanded shale, clay and slate provides the unique solution to this engineering problem. Please ask your ESCS producer for more information