For Flat, Curved & Sloping Roofs

For Flat, Curved
& Sloping Roofs

25 Year Guarantee

25 Year

Specialist Advice & Support

Specialist Advice
& Support

Express National Delivery

Express National

We've waterproofed 180m SqM of roofs!

We've waterproofed
180m SqM of roofs!

Request a sample

a sample

Rainwater Outlets

alwitra Rainwater Outlet Vertical

alwitra® Rainwater Outlet Vertical

Vertical, 100 or 125mm, with rigid polyurethane body and EVALON® flange, complete with screw ring and flat grating

  • Made of highly impact-resistant polypropylene (PP)
  • Pipes DN 125 (OD 125 mm) can be connected directly, pipes DN 100 (OD 110 mm) using the included reducer 125/110
  • A combined leaf guard/gravel stop is included
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alwitra Rainwater Outlet Horizontal

alwitra® Rainwater Outlet Horizontal

Horizontal, rigid polyurethane body with EVALON® flange, 125mm, complete with screw ring and flat grating

  • Made of highly impact-resistant polypropylene (PP) 
  • On classic warm roofs, all standard vapour barriers can be flashed directly.
  • Corresponding extension pieces are available in various lengths, depending on the thermal insulation thickness
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Refurbishment Outlets

Refurbishment Outlets

The two-part system consisting of a custom-fit refurbishment plate.

  • The plate is centrically arranged over the existing rainwater outlet and flashed against the existing waterproofing without backflow.
  • The drainage element itself is then simply inserted into the refurbishment plate.
  • 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).
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Emergency Outlet

Emergency Outlet

Mandatory emergency drainage systems for flat roofs with internal drainage.

  • This applies also to refurbishment. alwitra® rainwater outlets and extension pieces have been designed to meet this requirement
  • Available in different versions varying only in ponding height: • ponding height of 20 - 40 mm for emergency outlet socket 40 • ponding height of 20 - 100 mm for emergency outlet socket 100
  • Can be converted into emergency outlets with high performance and a specified ponding height. 
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Water Spouts

Water Spouts

Due to the flangeless design, alwitra® water spouts are particularly suitable for difficult and/or confined installation conditions.

  • They are made of rigid PVC and, depending on the version, are equipped either with a welding flange for EVALON®® waterproofing membranes or with a factory-fitted flashing collar made of EVALON®®.
  • Along with the alwitra® water spouts for pipes with various diameters, rectangular versions are also available
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Terrace Grate

Terrace Grate

The height-adjustable alwitra® terrace grate made of stainless aluminium

  • The grate is installed in place of the leaf guard / gravel stop, ensuring drainage at paving and waterproofing level.
  • Made from aluminium, with locating ring made of polypropylene (PP)
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Want to become an alwitra® accredited installer?

  • High-quality training
  • Become accredited
  • Receive new business leads from alwitra®

Apply Today

Our membranes are used by architects, contractors & developers. View all

Archdiocese of Liverpool
Coventry City Council
3D Reid
Balfour Beatty
InFrame Garden Rooms
Fife Council
Angell Thompson
Alec French Architects
Aloft Roofing & Leadwork
English Heritage
Glasgow Housing Association
Coomber Associates
Ashtree Roofing

Need expert advice or just have a question?

Our specialists are here to support you.
Just ask.

Contact Us 01202 785200

Here's what some of our clients have to say...

We have been alwitra® contractors for many years and have always been impressed with the results and reliability of the product. The customers…

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I, James Hopkins Director of JH Specialist Roofing install single-ply membranes on a daily basis, we as a company have tried numerous types of…

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We have used VSK extensively over the last 5 years, we have found it to be a great product and really good for complex detail work. We find using…

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As a small flat roofing business carrying out mostly domestic refurb work and small extensions EVALON® VSK is our preferred single ply membrane…

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We have been an approved contractor for many years, the level of customer service and the quality of the products provided by ICB (Waterproofing) is…

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We have worked with ICB on several occasions and we would thoroughly recommend them for their high level of professionalism and efficiency. The team…

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OB Architecture

ICB provides an excellent service with all the professional back-up required at the development stage through to completion. The manner in which you…

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I am pleased to recommend ICB as Company, through my personal experience and that of my Business, for the following reasons: They are an easy Company…

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We believe, as one of your approved contractors, over the years we have had a great working relationship with yourselves. When working on projects…

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Best system on the market – VSK all the way!!!!!!


alwitra® is a lovely membrane when you have some detailing and gutters as you can go all the way through in a oner…


…that’s the beauty of this membrane, (you) can complete field sheet and upstand in one go, nice and tight and (a) crisp finish in the…

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This product has to be the most versatile single-ply system we have used. Unbeatable finish.

Lee Orchard

EVALON® VSK – such a quality and versatile membrane.

Lee Orchard

In my mind the best single-ply.


Can’t beat VSK


We find all the staff at ICB, friendly, helpful & knowledgeable.


EVALON® VSK! Surely the best single-ply waterproofing membrane ever produced! A++++


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