FAQ

Although an anti-root membrane helps limit weed growth from the subsoil, naturally dispersed weed seeds cannot be completely avoided. Even with a root membrane, seeds floating in the air will find their way to the layer above the membrane.

When installing ECCOsedum green roofs, two risks are decisive: leaching or sliding of the substrate, and sliding of the entire system down the roof slope. The slope determines which precautionary measures are required.

Up to 15° (27%) ECCOsedum can be installed without additional measures. The specific build-up of the system provides sufficient erosion protection on these slopes.

Between 15° and 20° (27–36%) a batten system above the roof waterproofing is required. Wooden battens suffice here: the wood decays over time, but the substrate’s root penetration provides sufficient anchoring. Advantages of a system above the roof waterproofing: the waterproofing layer is not affected and no water stagnation occurs.

From 20° (36%) heavier measures are needed. There are two options:

1. Step system: segments the roof build-up into levels to reduce the effective slope, similar to a terrace construction.

2. Batten system — divides the substrate layer into compartments. The spacing between the battens is determined by the slope gradient. Two versions:

• Below the roof waterproofing: wooden battens, with a long service life. Battens without rounded edges require a protective layer to avoid damage to the waterproofing layer. Note: water retention behind the battens can negatively affect the sliding of the substrate.
• Above the roof waterproofing: battens generally made of plastic. The roof waterproofing is not affected and no water stagnation occurs.

Succulents, including many sedum species, can generally tolerate both sun and shade, but they usually prefer sunlight. They are accustomed to dry, sunny conditions and are well adapted to storing water in their leaves. This makes them extremely suitable for green roofs and gardens with limited water availability.

In shady conditions, succulents can also grow, but they will often perform less well than in full sun. They may grow more slowly, bloom less, and become less dense.

An ECCOsedum green roof consists of 3 layers:

1. Drainage layer: The tiles have a structure designed in such a way that rainwater that is not absorbed by the green roof system can quickly drain away without obstruction to the drainage points. The bottom drainage holes are located 1 cm from the underside so that non-capillary water can also be stored to a limited extent.
2. Substrate layer – water retention layer: The trays are filled with substrate to the full height (8 cm). In some places (at the level of the emergency overflows) the substrate thickness is 3.5 cm. The minimum thickness of the substrate is therefore 3.5 cm – the average thickness is 6 cm. The substrate layer has multiple functions. It provides nutrients and water for the vegetation and ensures oxygen and anchoring of the roots. The trays are filled with a roof-garden substrate, composed of lava, pumice and green compost.
   Water retention volume per tray: 32.5 litres/m²
   Grain size: 0–12 mm
   Bulk density of substrate after compaction in dry condition: 0.78 g/cm³
   Bulk density of substrate after compaction at maximum water capacity: 1.27 g/cm³
3. Vegetation layer: The pre-vegetated extensive green roof system is supplied with at least 7 types of sedum plants. The cassettes are delivered with at least 80% coverage.

Yes, the ECCOProtect400 root barrier fabric provides an additional buffer volume of 4 l/m².

Yes, thanks to the ECCOProtect400 root barrier fabric there is an additional buffer volume of 4 l/m².

• Our sedum trays are pre-grown up to 80–85%. This means you get instant results and we are talking about a ready-to-use system. With a traditional build-up, substrate layers and sedum cuttings/sedum mats are used, which always need a certain period to take root and grow densely. As a result, weeds get every chance to establish themselves in the green roof.
• The sedum cassettes are very easy to install and can be done by 1 person, which ensures a very fast and efficient installation. With a traditional build-up, blower trucks or big bags are used.
• Since the system uses trays, they can be very easily removed if any roof works are needed after installation. With the traditional system, the entire substrate layer must be removed in order to reinstall everything afterwards.
• The cassettes provide a constant substrate thickness. In traditional systems, the thickness of the substrate can vary between 1 and 8 cm, which also leads to weed growth.
• On roofs with a slope, the substrate remains in the tray. With the traditional system, there is a risk of slippage and of weed growth at the lowest point of the slope, since moisture settles at the lowest level and thus encourages weed growth.

When selecting the plant species, the following parameters were taken into account:

• Aesthetic value (e.g. flowering): wide sedum variety of at least 7 species.
• Drought resistance in relation to substrate thickness, substrate composition and water buffer. Since each sedum species thrives optimally under slightly different climatic conditions, a wide variety of sedum species provides greater certainty.
• Rate of propagation, to prevent one particular species from becoming invasive
• Regenerative capacity after extreme drought.
• Different flowering periods: when pre-growing ECCOsedum green roofs, cuttings material is used; these are runners from mother plants that are clipped off. To know the correct dosage of cuttings material for each sedum species, it is important to know how quickly they multiply after planting (to avoid monoculture). By using production fields (mother plants) each with a single sedum species, the correct mix of the cuttings material can always be guaranteed, which is important for a diverse roof vegetation.

ECCOsedum green roofs contain at least 7 sedum species:

• Sedum Immergrunchen
• Sedum Album
• Sedum Reflexum
• Sedum Sexangulare
• Sedum Acre
• Sedum Spurium
• Sedum Lydium

The choice of the cuttings mix and the dosage of each type was carefully studied with green-roof experts. The ECCOsedum green-roof system was also subjected to long-term tests on roofs and simulated extreme weather conditions. After various tests, the final plant mix proved to be highly efficient.

Regularly remove dirt, leaves and moss from the surface. The surface can be cleaned with a pressure washer (maximum 100 bar) at a minimum distance of 30 cm. Wait at least 7 days after grouting before cleaning the surface with a pressure washer.

Regularly remove dirt, leaves, and moss. Clean the entire surface annually with a pressure washer (max. 80 bar) at a distance of at least 40 cm.

Protect the newly jointed surface from persistent or heavy rain for 12 to 24 hours. For example, use construction film or a tarpaulin. Make sure, however, that the film is not lying directly on the surface, so that sufficient air circulation remains and the jointing compound can cure properly.

Use A-Joint® powered by ECCO only in well-ventilated outdoor areas. Wear suitable protective work clothing. Make sure work shoes and tools are clean before use and clean them with water during and after application.

For clinkers with bevelled edges, the rounded edge must remain visible. If it is not visible, the joint will be less strong. Therefore, remove about 1 mm of the jointing product so that the joint retains sufficient strength.

Install on a solid, permeable base with a slope of at least 2%

The sub-base must have a slope of at least 2% so that water drains away easily and does not accumulate between tiles, pavers and joints. This prevents moisture from seeping into the structure, which can lead to subsidence, frost damage or loose tiles.