Quality criteria \u2013 Substrates for green roofs<\/p><\/h1><\/div><\/div><\/div><\/div><\/div>
Granular drainage material is defined as mixtures of graded, purely mineral-based material that absorbs excess water from the vegetation support layer and drains it into the guttering. The material can store water to a limited extent and allow roots to grow through it. G\u00fctegemeinschaft f\u00fcr Substrate und Pflanzen e.V. inspects the material to assure quality.<\/p>\n<\/div><\/div><\/div>