FAQ

Although a weed control membrane helps to limit weed growth from the underlying soil, naturally dispersed weed seeds cannot be completely prevented. Even with a membrane, seed drifting through the air will find its way to the layer above the membrane.

When installing ECCOsedum green roofs, two risks are decisive: the substrate being washed out or sliding off, and the entire system sliding down the roof pitch. The pitch 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 pitches.

Between 15° and 20° (27–36%) a batten system above the roof waterproofing is required. Timber battens are sufficient here: the wood will decay over time, but root penetration of the substrate provides adequate 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 required. There are two options:

1. Step system: segments the roof build-up into levels to reduce the effective pitch, similar to a terraced build-up.

2. Batten system — divides the substrate layer into compartments. The distance between the battens is determined by the pitch. Two variants:

• Below the roof waterproofing: timber battens, with a long service life. Battens without rounded edges require a protective layer to prevent damage to the waterproofing layer. Note: water retention behind the battens can adversely affect the substrate’s resistance to sliding.
• Above the roof waterproofing: battens generally in 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 ideally suited 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, flower 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 drain away quickly and unobstructed towards the drainage points. The lower drainage holes are located 1 cm from the bottom so that non-capillary water can also be stored to a limited extent.
2. Substrate layer – water retention layer: The trays are filled to their full height (8 cm) with substrate. In some places (at the level of the emergency overflows) the thickness of the substrate 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 several functions. It provides nutrients and water for the vegetation and ensures oxygen and anchorage for 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-grown extensive green roof system is supplied with at least 7 sedum species. The modules 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 up to 80–85% pre-grown. This means you get immediate results and we refer to a ready-to-install 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 dense. 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 trays are used, they can very easily be removed in the event of any roof works after installation. With the traditional system, the entire substrate layer has to be removed and then everything reinstalled afterwards.
• The cassettes provide a consistent substrate thickness. With traditional systems, the substrate thickness can vary between 1 and 8 cm, which also encourages weed growth.
• On roofs with a pitch, 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 sinks to the lowest level and therefore promotes weed growth.

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

• Aesthetic value (e.g. flowering): a 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, in order to prevent one particular species from becoming dominant
• Regenerative capacity after extreme drought.
• Different flowering periods: when pre-growing ECCOsedum green roofs, cutting material is used; these are runners from mother plants that are cut off. To know the correct dosage of cutting material for each sedum species, it is important to know how quickly they propagate after planting (to avoid monoculture). By using production fields (mother plants) each with one sedum species, the right mix of cutting material can always be guaranteed, which is important for varied 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 mix of cutting material 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 to simulated extreme weather conditions. The final plant mix proved to be extremely effective after several tests.

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 pointing 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) from 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 building film or a tarpaulin. Make sure 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 workwear. Ensure that work shoes and tools are clean before use and clean them during and after application with water.

With bevelled-edge tiles, the rounded edge must remain visible. If it doesn’t, the joint will be less robust. Therefore, remove about 1 mm of the grouting product so that the joint retains sufficient strength.

Install on a stable, water-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 doesn’t pool between slabs, pavers and joints. This prevents moisture from seeping into the structure, which can lead to subsidence, frost damage or loose slabs.