Public Roof Retention

  • Suitable for traffic areas.
  • Water Retention Box WRB, including Flow Control system.
Weight from 400 kg/m² or from 4,0 kN/m²
Build-up depth from 250 mm
Roof pitch 0° 
Load class 1-3 (max. 160 kN/m2 and 16 t vehicle weight)

Top Layer

Pavement or slab covering, covering height depending on load class.

Bedding Material

  • E.g. bedding stone chippings 0–5 mm (30–50 mm)
  • Screed layer for surfacing material

Base Layer

Base layer of gravel 0-32 mm resp. 0-45 (height 150 mm minimum)

Filter Fleece FIL 300

Prevents fine particles from forming sludge in the drainage layer; high water permeability, very high robustness class GRC 5
Productdetails: Filter Fleece FIL 300

Water Retention Boxes WRB 85, WRB 95 or WRB 170*

Infiltration trough made of recycled PP intended for surface drainage in combination with a Flow Control System; high water retention potential
Productdetails:  WRB 85  WRB 95  WRB 170
*Selection according to load class, roof construction and required accumulation height. Please contact our Technical Department.

Flow Control System

(not shown in the drawing)

  • Throttle with defined perforations that allows a delayed water discharge
  • Permanent accumulation of stormwater possible up to a defined hight

Protection, Separation and Slip Layer SGL 500 and Separation and Slip Sheet TGF 0.2