For extensive and simply intensive green roofs with permanent water storage and runoff retardation, we recommend our RETENTION ROOF MEANDER FKM 60. The Meander water retention board FKM 60 is used as a drainage element. Part of the rainwater is permanently stored in it. At the same time, the outflow of the remaining rainwater is delayed, as it has to travel a longer flow path and is throttled at the outlet.

The Meander FKM 60 element thus ensures permanent water storage while at the same time delaying runoff and thus reducing the peak runoff coefficient. Permanent water storage and delayed water runoff in combination with biodiversity and evaporation make the Meander FKM 60 efficient a very high-performance product.

The permanent water storage of over 17 l/m² enables significantly more lush vegetation on the green roof. This contributes to an increase in biodiversity and an increase in evaporation capacity. This promotes cooling of the surrounding area, which in turn has a positive impact on the urban climate.

The RETENTION ROOF MEANDER FKM 60 is a mitigation measure within the framework of the impact compensation regulation and meets the requirements of the FLL Green Roof Guidelines.

Ecological value
Maintenance costs
Costs*	from 37 €/m2

* Depending on the load capacity of the substructure, Optigrün "High Density (HD)" or "Low Density (LD)" substrates can be used. Weight specifications refer to saturated conditions; dry weight is approximately 60 - 70 % of the saturated weight. In accordance with the requirements of the FLL Green Roof Guideline, the specified weight does not take temporary water accumulation into account.
** For the calculation of the dimensions of the pipe we recommend the discharge coefficient Cs = 0.1. Cs= 0.01 determined for 2 % according to the FLL Green Roof Guideline.