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!

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Evalon VSK
Evalon VSK Evalon VSK Evalon VSK Evalon VSK Evalon VSK Evalon VSK

The #1 self-adhesive waterproofing membrane

  • Self-adhesive underside coating
  • Bitumen-free & solvent-free
  • High adhesive strength
  • Ideal for steep slope or curved roof areas


Superior Self-Adhesive Waterproofing

EVALON® VSK membranes are based on our long-term proven alwitra® roofing system. The waterproofing membrane has both a polyester fleece-backing and a synthetic adhesive compound coating. After laying, the fleece-backing also reduces stress and strain on the system (vapour decompression, movement compensation, etc.). The coating is bitumen-free and solvent-free and covered with a protective film when delivered.

25 Year Guarantee

25 Year Guarantee

50 Year Service Life

50 Year Service Life

BREEAM Accredited

BREEAM Accredited


Trusted by architects, roofing contractors & developers

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EVALON® VSK is suitable for:

  • Steep sloped roofs
  • Curved roofs
  • Flat roofs 
  • Bridging expected cracks


  • Quick & Easy Install without additional adhesives
  • Time and labour saving
  • Clean install
  • Solvent-free self-adhesive backing
  • Direct laying onto bituminous materials
  • Superior adhesion without a flame

Product Details Back to top

Product Specification

All EVALON® VSK standard rolls are individually wrapped and laid horizontally on pallets of up to 15 units, for transportation.

Properties  Measurement
Effective thickness of waterproofing layer (mm) 1.2 / 1.5

Width (m)
- with welding edge on one side
- with welding edge on both sides

Lengths (m) 20* / 25
Specified lengths on request
Standard colours  white / light grey / slate grey
Special colours on request


*Only available for EVALON® VSK 1.05mm, slate grey

Technical Drawings

Evalon VSK
Evalon VSK
Evalon VSK

Technical Data

Properties  Testing Method  Unit  EVALON® VSK Results
Visible Defects EN 1850-2   passed
Effective Thickness (eeff)of waterproofing layer EN 1850-2 mm 1.2/1.5
Water tightness EN 1928 (B) kPa  ≥ 400
External Fire Performance ENV 1187 CEN/TS 1187   class BROOF (t1)+(t3)+(t4) confirmed by General Building Construction Supervision Test Certificates
Reaction to Fire EN 13501-1   class E
Joint Peel Resistance EN 12316-2 N/50mm  ≥ 150C
Joint Sheer Resistance EN 12317-2 N/50mm ≥ 400C
Max. Tensile Force EN 12311-2 (A) N/50mm ≥ 500
Elongation at Max. Tensile Force EN 12311-2 (A) % ≥ 60
Resistance to Impact Load EN 12691 (A) mm ≥ 300
Resitance to Static Load EN 12730 (B) kg ≥ 20
Tear Resistance  EN 12310-1 N ≥ 300
Tear Resistance EN 12310-2 N ≥ 150C
Resistance to Root Penetration  EN 13948   passedᵈ
Dimensional Stability  EN 1107-2 % ≥ 1
Low Temperature Flexibility EN 495-5 °C ≥ -30
Durability (UV Exposure, High Temperatures & Water EN1297 Visual Control passed
Durability of Water Tightness Against Artificial Aging EN 1296 EN 1928 kPa ≥ 60
Durability of Water Tightness Against Chemicals incl. water EN 1847 EN 1928 kPa ≥ 60
Hail Resistance EN 13583 m/s ≥ 30
Water Vapour Permeability  EN 1931 µ approx. 20,000
Bitumen Compatibility EN 1548   passed


Certifying body Testing 
State Material Testing Institute, Darmstadt, Germany External quality control Certificate of conformity according to DIN EN 13956 and DIN EN 13967
DEKRA Certification GmbH, Stuttgart Comprehensive external quality control of the product system
Society for Materials Research and Testing Institute for the Leipzig
construction industry

Warringtonfire Gent (Belgium)
Exova Warringtonfire (United Kingdom)
Tests with General Building Construction Supervision Test Certificate (AbP) according to DIN 4102-7 (resistance to flying sparks and radiant heat) as well as DIN CEN/TS 1187; Test methods 1, 3 and 4 (external fire load) with classification according to DIN EN 13501-5 resp. AbP Tests according to DIN 4102-1 (building material class B2) and
DIN EN ISO 11925-2 with classification according to DIN EN 13501-1 (class E)
Environmental Product Declaration EPD‘s for various application methods and material thicknesses according to ISO 14025 and EN 15804 corresponding to the guidelines of the Institute Construction and Environment (IBU)
German Institute for Building Technology (DIBt), Berlin, Germany European technical assessment ETA-08/0112 (ETAG 006)
Chamber of Agriculture Rhineland, teaching and research institute for Gardening and landscaping, Essen, Germany Testing according to FLL 84 (root penetration resistance)
Research institute, Field of Landscaping, Geisenheim, Germany Testing according to FLL 99 (root / rhizome penetration resistance)
British Board of Agrément (BBA), Garsten/Watford, UK Tests according to Building Standards Regulations
(England, Wales and Scotland), Certificate No. 96/3293
Scientific and Technical Center for Building), Marne Valle, France Avis Techniques
CSTB 5.2/19-2641_V1, CSTB 5.2/19-2640_V1
Factory Mutual / FM Global, Norwood, USA FM-Approval, Class 4470


Alwitra was the first enterprise of the industry to introduce relevant Environmental Product Declarations of the Institute Construction and Environment (Institut Bauen und Umwelt e. V. - IBU) for the EVALON®® and EVALASTIC®® waterproofing membranes.
For certifications according to DGNB, LEED or BREEAM alwitra® provides appropriate product fact sheets.


Applications Back to top


Loose Laid with BallastLoose Laid
with Ballast
Gravel, roof garden, concrete paving slabs
Mechanically FastenedMechanically
In the seam overlap or with field fastening
With compatible adhesives
With compatible primer
non ventilated roofs (warm deck roofs)





ventilated (two layer) roofs (cold deck roofs)





Substrate Quality

The substrate surface must be clean, dry and free of dust and grease.
Always prime with alwitra® Primer SK and ensure you use alwitra® Primer SK-L if applying at low temperatures as it takes less time to dry. Use at least 0.2 L / m2.
The supporting layer must be compatible with the membrane, solvent resistant, clean, dry and free of grease and dust.


Installation works must be carried out only by trained alwitra® roofing contractors. 
Would you like to become a dedicated alwitra® roofing contractor?
We can provide the necessary training on the installation of our products. 

Find out more

Case Studies Back to top

Documents Back to top

Evalon waterproofing membrane information

EVALON® Waterproofing Membranes

Download EVALON® Brochure (PDF)

Accessories Back to top



Superior Single-Ply Waterproofing

Superior single ply waterproofing at its best.

  • Bitumen-free & solvent-free
  • UV Stable
  • Root-resistant
  • Fire load five times lower than that of a built-up felt roof
Discover More


Superior Fire-Retarding Waterproofing

Superior Fire-Retarding Waterproofing

  • Compatible with bitumen
  • High thermal-mechanical resilience
  • Root and rhizome-resistant
  • High reflection of heat rays
Discover More


Superior Fire-Retarding Self-Adhered Waterproofing

  • Up to five times lower fire load compared to two-layer seals
  • Optimal vapour pressure compensation function of the polyester fleece or glass/polyester fleece backing
  • Self-adhesive underside coating
  • With the integrated fire protection layer, for direct bonding on unbacked rigid EPS foam boards
Discover More

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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