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

Refurbishment Vents
Refurbishment Vents

The alwitra® refurbishment vent 160 is made of CFC free PUR integral foam.

  • At the factory, an EVALON®® sealing ring is foamed into the welding flange. The sealing ring ensures permanently reliable flashing against the new roof waterproofing.
  • To this end, a prefabricated EVALON®  flashing collar is homogeneously welded to the sealing ring and the adjacent roofing membrane in the same way as the seam connection of the field membranes.

Refurbishment Vents

The thermally insulated alwitra refurbishment vent 160 offers an easy and reliable possibility of flashing existing vent lines up to DN 150 (OD160) against the new waterproofing without prior removal.


As used on landmark architecture throughout the world

almost 40 years experience with waterproofing systems in the UK

Almost 40 years experience with waterproofing systems in the UK

Find an installer


  • Other roofing membranes can be bonded to the 12 cm wide flange, also with hot bitumen. 
  • The vent cowl can be easily fitted and snapped into the pipe collar with four tabs.
  • The vent cross section has a top and lateral cover to protect against heavy rain
  • Condensate forming on the vent cowl (if any) will drip off without causing any damage, partly into the existing vent pipe


  • Suitbale for both warm and cold roofs

Product Details Back to top

Product Specification

Material: PUR integral foam, with foamed-in EVALON®® or EVALASTIC®® sealing ring; PE vent cowl
Colour: Connecting flange: in the colour of the waterproofing membrane
Height above the waterproofing (excl. cowl): 300 mm
Inner diameter: max. 169 mm (DN 150)
Ø of screw holes at flange: 470 mm
Outer flange diameter: approx. 375 mm
Flange width: 120 mm
Outer diameter of optional connecting flange: 670 mm

Technical Drawings

Refurbishment Vents
Refurbishment Vents

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…

Read Full Review


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…

Read Full Review


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…

Read Full Review


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

Read Full Review


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…

Read Full Review


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

Read Full Review

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…

Read Full Review


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…

Read Full Review


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

Read Full Review


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…

Read Full Review


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++++


Find an Installer

We're ready to help, just fill out this form and we’ll get straight back to you.

Find an installer

We use cookies. By using the website you agree with our use of cookies. For more information, please read our privacy policy.

Okay, got it!
Full screen