Technical specifications Green Roofs

Mutual anchoring: The trays have been provided with recesses and bulges on the sides to prevent them from shifting from and towards each other.

Vertical anchoring: Two lips per tray ensure that all trays are anchored together and that they cannot blow upward. Each tray grips over the edge of 2 neighbouring trays and is in turn held by 2 other trays.

The trays have vertical recesses and emergency spillways so that rainwater that is not absorbed by the green roof system can drain off easily.

The trays can be used on flat and slightly sloping roofs with an angle of inclination of up to 25 degrees. For applications on larger slopes or over lengths longer than 20m, a structure will need to be provided to limit splashing forces. The advantage of the tray system on sloping roofs is that it is a compartmentalized system; each tray is given the same amount of water so that there is a constant in the vegetation.

The tray consists of a drainage layer, a substrate layer with an important water buffering capacity and a vegetation layer.

The buffer volume of the sedum trays in combination with the protective layer is at least 35 l/m².

Drainage layer:

The trays have a structure designed in such a way that rainwater that cannot be absorbed by the green roof system can drain away without obstruction to the drainage points.

The lower drainage holes are 1cm from the bottom so that even non-capillary water can be stored to a limited extent.

Substrate layer – water buffering layer:

The cassettes are filled with substrate up to full height (8cm). In some places (at the level of the emergency spillways) the thickness of the substrate is 3.5cm. The minimum thickness of the substrate is therefore 3.5 cm - the average thickness is 6 cm.

The substrate layer has several functions. It provides nutrition and water for the vegetation and provides oxygen and anchoring of the roots.

ECCOsedum uses a roof garden substrate, composed of lava, pumice and green compost.

Volume of water buffering per tray: 32.5litre/m²

Granularity: 0-12mm

Volume weight of substrate after compaction in dry state: 0.78g/cm³

Volume weight of substrate after compaction at maximum water capacity: 1.27g/cm³

Vegetation layer:

The pre-cultivated extensive green roof system is supplied with at least 7 species of sedum plants per m². The cassettes are at least 80% full-grown upon delivery.

2. Technical specifications ECCOsedum:



Tray composition

100% recycled and 100% recyclable PP

Tray Dimensions

49 x 45,5 cm

Tray height

8 cm

Dry weight

11,7kg/tray – 51,5kg/m²*

Weight saturated

 19kg/tray – 84kg/m²*

Number of trays per m²

4,4 pieces

Water storage capacity

32,5 litre/m²

Total volume of substrate per grid

15 litre*

*These are theoretical values. In practice this may vary slightly because the trays may expand when filling them with substrate.

3. Installation of sedum trays

Installation of a root-repellent layer

Anti-root film should not always be used with EPDM or PVC, unless specifically requested by the manufacturer.

Installation of the protective layer

The protective layer is recommended at all times. This to prevent damage to the roof waterproofing during installation + because of the extra water buffering volume.

Technical data PROTECTcloth:

Material: Inorganic felt cloth

Weight: 300gr/m²

Height: approx. 5mm

Roll width standard: 2.00m

Water storage capacity: 3-4l/m²

Installation of the sedum trays

The trays are held together by a click system and are cut to size using a saw or grinding wheel. The cut side is best placed against the previous tray to reduce the risk of dehydration.

Any edge zones can be filled with roof gravel.

Maintenance of your sedum roof

Although a do-it-yourself green roof requires little maintenance, an inspection twice a year is recommended.

The green roof can be walked on for maintenance, not to stay on permanently as a roof terrace. In this respect, you need to provide tiles in wood or concrete.

The following works are necessary:

  • Removal of unwanted weeds and seedlings from trees (2 times a year)
  • Fertilise with the specially formulated fertiliser (once a year, 30 g/m2).
  • Removal of weeds from the gravel edges
  • Cleaning the rainwater drain