A new technical development was announced combining the “Summer Plains” system with Aquatec.
An intensive green roof using the Aquatec system accounts for only 165 kg/m² and a build-up height of only 15 cm, even on a pitched roof, which is just about half the values for a conventional “roof garden”.
The first layer of the system build-up involves the installation of a PV system filter as a protective layer on the root-resistant waterproofing membrane. This is followed by the 1 x 2 m Aquatec AT 45 water distribution, storage and drainage elements in conjunction with the DV 40 wicking mat. It provides for the distribution and storage of water in the cells of the Aquatec elements. The water is then drawn upwards through the wicks in the wicking mat and made available to the substrate directly in the root area. Water storage in the Aquatec elements is managed by means of precipitation or, in the event of a lack of precipitation, by means of the drip lines clipped into the elements. The water supply is connected to a control unit and adjusted as required.
During the planning phase, it is vital to take into account the existing roof pitch and any uneveness in order to ensure a uniform level of water storage. The system is flexible here, meaning that it can manage a range extending from 0° to a pitch of over 5°. The boards are shaped in such a way that minor irregularities in the roof are easily covered over. In addition, it is important to ensure that the water pressure is sufficient. This depends on the distance of the individual irrigation sections to the control unit, the drip line lengths and any differences in pitch of the roof.
Water and cost savings
In comparison to a conventional system providing additional irrigation from above, for example a lawn sprinkler, water consumption with the “Summer Plains” system build-up is significantly reduced as the water is available directly in the root area and does not evaporate to any extent on the surface. The drainage elements do not have to be filled as is the case with other systems which saves on weight and labor and on cost.
This irrigation concept allows for the use of a shallow substrate depth compared with conventional intensive green roofs, which also results in less effort and lower costs. However, the substrate depth should not be less than 10 cm as otherwise the level of evaporation from the plant layer would be too great.
In terms of vegetation, anything is possible with the “Summer Plains” system build-up, from extensive to intensive green roofs, depending on the selected substrate depth and the suitability of the plants for the given location.
With a substrate depth of 10 cm, the user can conjure up a simple intensive green roof with blossoming perennials, fragrant herbs or dwarf shrubs, or even a herb lawn turf specially developed for this build-up and the green roof is done. Only 8 cm of substrate are required here and a further 2 cm substrate are added with the turf lawn. Additional substrate allows for the use of higher-growing shrubs together with all the features of an intensive green roof. Combinations with terraced areas and pathways are always possible, regardless of the type of green roof. However, they are either separated from the irrigation system or bridged over, depending on the size of the area covered.