Water storage membrane DELTA®-FLORAXX

Diffusible protective and drainage membrane with water storage function. Surface drainage and water storage in one. Ideally suited for use on green as well as on inverted roofs.

The dimpled membrane is safe for drinking water, resistant to chemicals and does not rot in the ground.

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    DELTA®-FLORAXX in der Anwendung
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    Laying DELTA®-FLORAXX on a protective layer, for example a spun fibre fleece of 300g/sqm
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    DELTA®-FLORAXX material
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    DELTA®-FLORAXX in the inverted roof. Base layer on a separately laid, filter-stable geotextile.
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    DELTA®-FLORAXX im Gründach


  • Large water reservoir of approximately 7 l/sqm
    DELTA®-FLORAXX stores rainwater. This is why it serves as a water reservoir for dry periods. Excess rainwater can run off through the perforation holes punched in the dimpled sheet and can be drained on the roof waterproofing between the knobs.
  • 80% higher compressive strength
    Thanks to the octagon knob with reinforcing ribs, it has an approx. 80% higher compressive strength than standard nubs.
  • Vapour-permeable
    Thanks to its perforation, the dimpled membrane is open to diffusion (with an SD value of approximately 0.4 m) by enabling unhindered drainage as well as vapour pressure relief. This prevents a closed water film from forming on the insulation and damaging it.
  • Logistics
    DELTA®-FLORAXX FLAT is also available in the format 2.35 x 1.00 m as sheet goods. 200 pieces and/or 470 sqm per industrial pallet. (Compare DELTA®-FLORAXX: 240sqm (6 rolls) on an industrial pallet)


DELTA®-FLORAXX is also used in the inverted roof as a diffusion-open cover for the thermal insulation. The dimpled sheet is laid on a water-draining separating layer with the knobs facing the roof insulation. Then the required fill (plant substrate, chippings, gravel, crushed stone, etc.) is applied to a filter-stable geotextile laid separately on DELTA®-FLORAXX. Even in the inverted roof, greening, the creation of terrace areas or simple gravel is possible without any problems.

DELTA®-FLORAXX serves as a protective, drainage and water storage layer in extensive as well as intensively greened flat roof constructions. The dimpled sheet is rolled out on a protective fleece (min. 300g/sqm) above the root-proof seal with the dimpled side down. This is followed by a filter-stable geotextile on which the plant substrate is applied in the next step. The planting is then done individually.


Technical data

Material of the dimpled sheet HDPE dimpled sheet perforated
Dimple height approx. 20 mm
Compressive strength approx. 200 kN/m² (EN ISO 604)
Air gap approx. 14 l/m²
Servicetemperature range -30 °C bis + 80 °C
Water flow capacity in the plane approx. 10 x 10-3 m²/s (10 l/s · m) (EN ISO 12958)
Water permeability with vertical inflow approx. 8,5 l/m² · s
Perforation diameter approx. 6,5 mm
Water storage capacity approx. 7 l/m²
CE conformity Standard DIN EN 13252, test report no. 1.1/13525/0394.01-2009
Roll dimensions 2,0 m x 20,0 m , 2,35 m x 1,00 m (DELTA®-FLORAXX FLAT)




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Would you like information on detailed product properties, use cases or other technical topics?
Then feel free to contact our application department on +49 2330 63 578 or atabvf@doerken.de.

Do you have questions about prices, availability or the status of your order?
Our sales service will help you with these matters on +49 2330 63 636 or membranes@doerken.de.