Vegetation and storage layer
The vegetation and storage layer is the basis for plant growth and enables root growth. Its task is to store water and make it available to plants. This layer is required to be stable, maintain an appropriate pH value, collect the right amount of water, and provide proper air circulation. The precise thickness of the vegetation layer depends on the designed greenery, and it ranges from 5 to 10 cm in the Xero Flor system. It is enough to maintain the necessary moisture for plants and ensures their trouble-free development. In the XERO FLOR system, the function of the vegetation and retention layer is performed by:
- XF 200 mineral substrate,
- XF 107 hygroscopic rock wool,
- GR WR 1000 storage geotextile
It is made of a mixture of mineral rocks with appropriately selected granulation. The thickness of the substrate layer depends on the designed greenery, and it ranges from 5 to 10 cm in the XERO FLOR system. It is enough to maintain the moisture necessary for plants and ensures their trouble-free development at the same time. The composition of the substrate
consists of products of mineral origin with a small addition (max 10% by weight) of organic ingredients. It is characterized by a stable skeleton structure, resistant to frost and UV radiation. The air content in the substrate does not exceed 10% with the maximum water saturation. The salt content practically does not exceed the value of 1.0 g/l of the substrate. The substrate has an appropriate water storage capacity at the level of min. 15% by volume. Technical requirements for the thickness of the substrate layer on the roof are limited to the maximum weight that the roof can carry.
Hygroscopic rock wool made of basalt and limestones is the substitute for the mineral substrate. In terms of water absorption, a 3 cm layer of rock wool replaces 6 cm of the substrate. Hygroscopic rock wool is a special type of mineral wool. It does not contain impregnants. It is to ensure the best possible vegetation conditions for plants, characterized by high water retention and resistant to decay processes. It ensures the accumulation of water at the level of approx. 18 l/m2. It is used in the construction of extensive green roofs as a substrate substitute due to its very light weight.
Non-woven fabric which functions as an absorption layer, storing water. Made of polypropylene and cotton fibers obtained in recycling processes. It has a water absorption of approx. 9 l/m2. Biologically and chemically neutral to bituminous coverings and vegetation.