Make your own green roof - this is how it works

If you proceed carefully and professionally and use the right material, you can create a green roof yourself. The following instructions reveal what there is to know and pay attention to, and how to build the green roof correctly.

Check beforehand

  • Load-bearing capacity of the roof
  • Roof pitch
  • Diameter and position of the roof drain
  • existing roof waterproofing
  • Also read - green roofs - extensive or intensive?
  • Also read - The structure of the green roof
  • Also read - Green roofs on a pitched roof

Based on these factors, it can be assessed whether greening is possible.

Load-bearing capacity of the roof

Green roofs represent a high roof load. In the case of extensive greenery, the roof must bear a load of at least 60 - 80 kg. In the case of intensive greenery, roof loads of over 100 kg must be possible.

Roof pitch

Roof slopes between 0 and 5 degrees are ideal. Pitched green roofs require a special static assessment and special construction measures.

Diameter and position of the roof drain

The roof drain must be in a suitable location and have a sufficiently large diameter.

Existing roof waterproofing

The existing roof waterproofing must remain sufficiently tight even under the weight of the greenery. A check for leaks and damage is necessary beforehand.

Intensive versus extensive greening

Extensive greenery is planted with cacti, moss and succulents. They only have one substrate layer.

Intensive greenery has a complete soil structure. They can be planted with all garden plants. They bring roof loads of over 100 kg with them. The cooling effect on the rooms below is greater due to the evaporation cooling than with extensive greenery.

The individual layers are built up in the same way down to the bottom layer for both types of greenery.

Greening packages

Individual manufacturers, such as Optigreen, offer "greening packages". These packages include all the layers required for extensive greening.

Before installing the greenery, the roof waterproofing must be checked to ensure that it is suitable. Otherwise an additional sealing layer must be applied.

Correctly build up green roofs (extensive)

  • "Greening package " with individual layers
  • possibly. Sand (for seeds)
  • Seeds or
  • Extensive planting
  • screwdriver
  • cutter
  • Rake
  • broom

1. Check roof and clean

Check the roof sealing for leaks and damage. Swept the roof clean. There must be no chips or splinters on the roof.

2. Lay the root protection film

Spread out the root protection film and cut to size. Lay several foils with an overlap of 1.5 meters. Ends under the tapping. Cut a correspondingly large hole in the slide in the drain area.

3. Lay protective fleece

Lay the protective fleece with 10 cm overlap. Crop and put under the tin storage. Cut a hole in the drain area.

4. Lay solid state drainage

Pay attention to the correct location of the top. Lay out plates and overlap some centimeters. Cut a hole in the plates in the area of the roof run.

5. Lay filter fleece

Filter fiber spreadout spread and embark with about 10 cm overlap. Cut a hole in the area of the roof drain.

6. Insert control shaft

Insert control shaft over the roof.

7. Substrate

Rub extensive substrate and distribute roughly. Use the rake to produce a uniform thick layer of about 6 - 8 cm. Filter fleece cut off something about layer height.

8th. Apply seed or plants

Either apply seeds mixed with sand evenly, or use the prepared planting.

9. Water

Water the roof surface until all layers are soaked. Keep constantly moist during the rooting phase (around three weeks, depending on the planting).

Tips & Tricks A planting concept should, if possible, be drawn up by a specialist, even for extensive greening. This creates a balanced look.