ICB (International Construction Bureau) Limited Alwitra rainwater outlets and accessories are designed for use with ICB's EVALON® or EVALASTIC® single layer roofing systems. They are available in both vertical and horizontal forms.

Features and benefits:

  • Adapted to the specific requirements for rainwater and emergency outlets for low slope roofs.
  • Provides high discharge rate and a low ponding height.
  • Manufactured from highly impact resistant polypropylene (PP).
  • Various combination possibilities are available.
  • Tested according to DIN EN 1253.

Related literature

The following content references this product:



- Vertical/ Horizontal:

  • Vertical: S 125/ 110 and SH 125/ 110 for DN 125 and DN 100.
  • Horizontal: W 75/ 110 and WH 75/ 110 for DN 70 and DN 100 as well as W 125 and WH 125 for DN 125).

Provides the connection between drainage pipes and the water-proofing at cold or inverted roofs.

- Refurbishment Vertical:

For use in the case of refurbishment with additional thermal insulation, where it is not possible to replace existing outlets. Uses the custom-fit refurbishment plate (DN 125 made of PP, DN 100 and DN 70 made of aluminium), which is flashed against the existing waterproofing without back flow. Flashing against the new waterproofing is carried out either with connecting flange and screw ring (refurbishment rainwater outlet 125) or with factory-fitted connecting flange (refurbishment rainwater outlet 75, 110).

- Waterspouts:

Part of the roof and emergency drainage system for non-used or extensive green roof areas covered with EVALON® waterproofing membranes. They can be installed horizontally through the para-pet. Made of rigid polyvinyl chloride (PVC) and, depending on the version, are equipped either with a welding flange for EVALON® waterproofing membranes or with a factory-fitted connecting flange made of EVALON®. Along with the waterspouts for pipes with various diameters, rectangular versions are also available. These rectangular water spouts feature high discharge rates at low ponding heights.


EVALON® or EVALASTIC® flexible flange for connecting to EVALON® or EVALASTIC® single layer roof coverings.


  • Flexible bellows connectors: Neoprene rubber for use on lightweight roofs subject to movement and vibration caused by wind pressure and suction, plant, etc.
  • Heating element: 24 volt system to prevent freezing.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
90-10-20/302 Gravity rainwater outlets

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Alwitra, Product of ICB (Waterproofing) Ltd


+44 (0)1202 785200

Product reference

Alwitra Rainwater Outlet


[Horizontal DN70/ DN100/ DN125]
[Refurbishment Vertical DN70/ DN100/ DN125]
[Vertical DN70/ DN100/ DN125/ DN150]
[Waterspout S DN50/ DN70/ DN100]
[Waterspout SF DN50/ DN70/ DN100]
[Waterspout SW DN50/ DN70/ DN100]
[Waterspout SF Rectangular 100/ 300/ 100/ 500]
[Waterspout SW Rectangular 100/300/ 100/500]




[Leaf Guard]
[Terrace Grate]


[Not required]
[Flexible bellows connector]
[Heating element]
[Reducer, 100 to 70 mm]
[Reducer, 125 to 70 mm]
[Reducer, 125 to 100 mm]

Manufacturer details

Unit 9-11,
Fleets Industrial Estate,
Willis Way,
Dorset, BH15 3SU
Tel +44 (0)1202 785200
Fax +44 (0)1202 785201
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