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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a sample

Paving Slab Supports
Paving Slab Supports Paving Slab Supports

Paving slab supports for use on terraces and balconies

  • Allows for movement
  • Prevents cracking
  • Free and efficient drainage
  • Additional Shims available to allow for
    greater levelling adjustment

Paving Slab Supports

Paving or Tiles on terraces and balconies need to be installed with an allowance for movement. This will prevent cracking as a result of thermal stress. If cracks occur, water can enter and when “frozen” it can destroy the covering. This is also true of paving slabs or other types of hard walkways which are laid in cement or other mortar beds where purely surface drainage cannot be guaranteed. In these circumstances, subsequent damage can also occur to the waterproofing layer and flashings. Those risks can be avoided if the slabs are laid with open joints on alwitra paving slab supports.

almost 40 years experience with waterproofing systems in the UK

Almost 40 years experience with waterproofing systems in the UK


Trusted by architects, roofing contractors & developers

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  • Offers free and efficient drainage
  • Rainwater Outlets and Gutters/Rainwater channels can be hidden
  • Frost damage can be avoided
  • No efflorescence on the paving slabs
  • No decomposing of outlets due to lixiviation of lime
  • Considerably efficient sound insulation


  • For terraces and balconies
  • Suitable for single-ply membranes made of thermoplastic or elastomer type or multi-layer bituminous roofing

Product Details Back to top

Technical Data

PA 20

Polymide Black

Temperature-resistant from -40 to +100°C

Base Plate

Diameter 150 mm

Surface 175 cm2


Quantity x4

Diameter (width of joint) 6 mm

Height 65 mm

Slab Support

Quantity x4

Diameter 30 mm

Individually height adjustable by 20 mm, protected against reverse turning and overtightening, from 35 to 55 mm, preset on 40 mm 

Load capacity 4 x 2 kN (800 kg)

Tile Spacer

Quantity x1

Height 23.5 mm

Thickness 6 mm

Impact sound improvement measurement Δ Lw,R = 28 dB

50 x 50 x ≥ 4 cm

40 x 40 x ≥ 5 cm


4 pcs/sqm for a slab size of 50 x 50 cm 

About 6.3 pcs/sqm for a slab size of 40 x 40 cm

Packing Unit 24 pieces

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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

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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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