Airy garden: the intensely green roof

Usable space at lofty heights: You can find out what requirements a roof has to meet for intensive greenery and the most important tips for care and maintenance in our guide.

Basics of intensive green roofs

Basically, an intensely green roof is very similar to a normal garden in terms of type and maintenance. Depending on the type of greenery, perennial shrubs, various woody plants and even trees are used here. The design of an intensive green roof is only limited by the statics - a park-like green area on the roof brings loads of up to 1200 kg per square meter with it. Since the intensive greening is also very maintenance-intensive, roof gardens are normally only implemented on roofs with a roof pitch of 0 - 5 °.

  • Also read - Visually and ecologically valuable: the extensively green roof
  • Also read - green roofs - extensive or intensive?
  • Also read - Get nature on your roof with a green roof

The beginnings of an intensive green roof are mixed green roofs, also known as extensive intensive roof greening. The total layer structure for this very simple form of intensive greening is 25 cm, for complex greening the structure is up to 100 cm. Intensive greenery requires regular irrigation and nutrient supply. This means that care and maintenance work has to be carried out several times a year. Often, such roof gardens serve as an additional floor space for humans - that means extremely high demands on construction technology. Then, however, traffic areas such as ways, terraces and even routes can be applied on the roof. The cost of intensive roof greening starts for the simplest form at 50 euros per square meter.

Layer structure for intensively green roofs

On the roof construction, the following layers are set up:

  • Root-resistant roof seal
  • Water tub
  • Guard
  • drainage
  • Filter fleece
  • Substrate
  • vegetation

The layer thickness of the substrate is determined depending on the desired type of planting and ultimately determines the total weight that the roof construction must be allowed to carry.

Maintenance and care work

Like every roof, green roofs must also be maintained regularly. While maintenance once a year is usually sufficient for extensive green roofs, roofs with intensive green roofs require significantly more care. In addition to the work, which also requires an extensively green roof, a number of other measures have to be taken. Unwanted growth must be removed regularly, the plants regularly need nutrients in the form of fertilizer. In contrast to an extensively green roof, an intensive green roof must be watered regularly. You have to remove cuttings, leaves and rubbish, if there are deficiencies, you have to re-sow and replant. You need to regularly replenish the substrate and ensure that the plants are adequately protected.
Edge and safety strips, slabs and other coverings must be cut free on a regular basis, the safety gutters, inspection shafts, roof drains and drainage systems must also be maintained and kept clear.
In addition, with intensive greening, of course, all of the work that occurs in any normal garden. You should therefore expect 8 - 12 maintenance cycles per year.