Masonry – EWI (Epsitherm) – Silicone Render

Masonry – EWI (Epsitherm) – Silicone Render

Wetherby Building Systems Ltd Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

  • QA Certificate

    QA Certificate

    Certificate type

Render carrier board silicone render system

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+44 (0)1942 717100


The WBS Epsitherm Insulation System offers a versatile, cost effective solution for both new build and refurbishment applications. It is ideal for use on a variety of substrates including brickwork, blockwork, steel frame, timber frame and structurally insulated panels (SIPS).

WBS Epsitherm insulation boards are manufactured without the use of CFCs or HCFCs and therefore have a zero ODP.

Epsitherm offers improved U-values in comparison to standard EPS with a thermal conductivity as low as 0.030 W/m²K.

WBS Epsitherm can be finished using a variety of final finishes or textures, including silicone & acrylic renders, cementitious renders, dashing aggregates and brick slips.


  • Offers a low cost, economical solution.
  • Epsitherm is a lightweight insulation offering good adhesion.
  • Enhanced low thermal conductivity of 0.030 - 0.032 W/m²K.
  • Provides good workability – easy to cut and profile.
  • Suitable for new build & refurbishment projects.
  • Suitable for high, medium & low rise properties.


  • This system has an assessed anticipated lifespan in excess of thirty years.

Movement joints:

  • Where movement joints are present in the existing substrate, it is highly recommended that they are carried through the WBS system. Please consult with WBS Technical Support for further details on where movement joints are required.

Design Considerations:

  • Should the proposed project incorporate any unique design elements or curved elevations, please contact WBS Technical Support for recommendations or assistance.

General information


Silicone Render


10 year guarantee on BBA approved systems

Uniclass 2015

Ss_25_45_72_28 External wall insulation systemsPrimary


M21/20 External wall insulation system . . . . . .

M21/210 External wall insulation system

Product range

External Wall Insulation Systems

Specification data - External wall insulation systems

Product Reference

WBS Epsitherm External Wall Insulation System




Existing brickwork/ blockwork

New brickwork/ blockwork

SFS/ Steel frame


Timber frame

Substrate preparation

Not required

WBS Fungicidal Wash

WBS Stabilising Solution

Movement joints

Not required


Fire breaks

Not Required





WBS Epsitherm Insulation Boards


Insert requirement.

Insulation fixing

Mechanical only

Adhesive and mechanical

Secondary Fixing


Not required

Board adhesive

WBS Bedding Adhesive




WBS Alkali Resistant Scrim Cloth incorporated into bedding adhesive

Reinforcement adhesive

WBS Scrim Adhesive

WBS UF Adhesive

WBS Premium Scrim Adhesive

WBS K&A Adhesive

WBS HPX Adhesive

WBS Brick Slip Adhesive




WBS Ashlar Effect Render

WBS Brick Effect Render

WBS Brick Slip

WBS Epsibrick 7 mm Brick Slip

WBS Epsicoat Mineral Render Plus

WBS Heck ED Mineral Render

WBS Roughcast

WBS Silicone/ Acrylic 'K', Grain size ___ mm

WBS Silicone/ Acrylic 'R', Grain size ___ mm

WBS Spar Dash Finish


Insert requirement.


WBS Aluminium beads, trims & amp; profiles

WBS Plastic beads, trims & amp; profiles

WBS Polyester coated galvanized steel beads, trims & amp; profiles

WBS Stainless steel beads, trims & amp; profiles

WBS Low Modulus Silicone Sealant

Standard product features


- WBS Premium Polystyrene SD/ FRA Grade (Premium EPS):

  • Thickness: 10–300 mm+.
  • K Value: 0.030–0.032 W/m²K.
  • Thermal calculations are carried out for each project to help to determine the thickness of insulation required to meet current Building Regulation requirements.

- Fire performance:

  • Expandable polystyrene is combustible when tested in accordance with BS476 Part 4 or EN ISO 1182. The actual fire rating is dependent on the type of decorative finish used.
  • When used on multi-storey buildings, fire breaks must be incorporated into the system at every floor level above 1st floor and at each compartment wall abutment. Please refer to BR 135 ‘Fire Performance of External and Thermal Insulation for Walls of Multi Storey Buildings’; 2nd edition, 2002.

Product Options


  • Where mechanical fixings are required, the length, type and number of fixings required can only be determined following an on-site pull out test.
  • Secondary pinning may be required on high-rise applications. Please consult with WBS Technical Support for recommendations.


- Polymer modified renders:

A range of BBA certified through coloured polymer modified renders are available in a variety of colours. Special colours may be available on request.

- Dry dash:

A wide range of coloured dashing mortars and complimentary dashing aggregates are also available. A list of standard colours can be found at:

- Flexible Silicone & Acrylic Finishes:

  • WBS flexible silicone & acrylic thincoat finishes are supplied pre-mixed and are available in 100 standard colours. Special colours and colour-matching to other manufacturer's palettes may be available on request. WBS silicone and acrylic finishes are available in four standard grain sizes in the 'K' range and two grain sizes in the 'R' range. Other grain sizes can be acquired on request.
  • WBS Silicone & Acrylic systems are certified for European Technical Approval from the DIBT, Germany. ETA is an EEC wide accepted equivalent to BBA. Standard.
  • Please consult with WBS technical department before specifying any dark colours with a lightness value of less than 20.

- Epsibrick Brick Slips:

The basis of the WBS Epsibrick Brick Slip System is the specially profiled galvanised steel/ stainless steel brick mesh which is fixed directly onto the EWI system. The mesh is fixed using specialist fasteners of the appropriate length to give a suitable penetration into all types of substrate, which must comply with wind loading requirements. Due to the overall weight of the system, it is recommended that WBS brick slips are only used up to three storeys.

- Epsibrick 7 mm Brick Slips:

WBS Epsibrick 7 mm Brick Slip System incorporating real clay brick slips adhesively fixed to a high impact, reinforced basecoat. The reduced brick slip thickness makes this an extremely durable, lightweight system, offering a wide range of colours, enabling tenants to retain the look of their original brick façade.

-Epsicoat Mineral Render Plus:

A unique through coloured mineral render requiring no painting or sealer coat. This system allows application in lower temperatures/ higher humidity and is rainproof within 2 hours. Available in 8 standard colours. Details of the Epsicoat Mineral Render Plus system can be found at:

-Heck ED Mineral Render:

A high performance mineral render allowing quicker drying times in lower temperatures/ higher humidity. Heck ED Mineral Render requires 2 coats of silicone paint, tinted to the colour of the clients choice with 100's of options available through our NCS colour range. Details on the Heck ED Mineral Render system can be found at:

Digital objects

Platform Compatible Version Certified to



Revit 2016


Download now from NBS National BIM Library

Third party certifications

  • 03/4058
  • European Technical Approval: DIBT Certificate 05/0045 EPS

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