If the waterproofing material applied in green roof areas is not resistant to plant roots, it is placed just above the existing waterproofing. (If there is protection concrete, it is laid on it.) They are low-density polyethylene mattress covers that are resistant to the roots of the plants and produced with additives that prevent the roots from damaging the insulation vertically and allow the roots to develop horizontally. It is also used as a vapor barrier between two concretes.