NBS Source
I'm a manufacturer

HECK ETA 18_0229 - Stone Wool, Silicone Render (A2) and Mineral Render (A1)

Verified by manufacturer over a year ago

Wetherby Building Systems Ltd Third party certifications:
  • European Technical Approval (ETA)

    European Technical Approval (ETA)

    Certificate type

A masonry ETA certified system consisting of a stone wool insulation board, basecoated, meshed, finished off with a silicone render (A2) and mineral render finish (A1).

Jump to:
BOS
+44 (0)1942 717100 Website

Application

Suitable for use on the outside of masonry substrates of new or existing domestic and non-domestic buildings, without height and boundary restrictions (see systems ETA certificate for further information).

Description

An ETA certified system consisting of stone wool insulation board mechanically and adhesively fixed, basecoated, meshed, finished off with a silicone render (A2) and mineral render finish (A1).


Features and benefits:

  • The systems can improve the thermal performance of external walls and can contribute to satisfying the requirements of the National Building Regulations.
  • The systems can adequately resist wind loads and impact damage.
  • This system can achieve an A2-s1, d0 reaction to fire classification for Silicone Render System. A1 Mineral Render System achieves an A1 reaction to fire classification.
  • The system can contribute to a limiting risk of interstitial and surface condensation.
  • When installed and maintained in accordance with the Certificate holders recommendations and this Certificate, the system will remain effective for at least 25 years.
  • For further information on the above points please visit the system’s ETA Certificate.

General information

Warranty description

Ten year

Uniclass

Ss_25_45_72_28 External wall insulation systemsPrimary

CAWS

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

M21/210 External wall insulation system

Specification data - External wall insulation systems

System performance

Reaction to fire classification to BS EN 13501-1, A2-s1, d0. Design life duration (minimum): 25 years.

Guidance for specification option:

This system can achieve an A2-s1, d0 reaction to fire classification for Silicone Render System. A1 Mineral Render System achieves an A1 reaction to fire classification please contact Wetherby Building Systems for further information on this.


When installed and maintained in accordance with the Certificate holders recommendations and this Certificate, the system will remain effective for at least 25 years.

Preparation

Ensure surfaces are sound, free from loose material and clean.

Guidance for specification option:

Remove any loose material and existing render, where required dub out the surface level, ready to receive the EWI system. The existing walls are to be cleaned with a wire brush or pressure jet wash, to the satisfaction of the Contract Administrator, to remove any friable material, algae or lichen, and to provide a good key for Wetherby products. 

Wetherby Dubbing Render.

Guidance for specification option:

Where necessary dub out any hollow or defective areas to leave a suitable surface for the application of the insulation boards. Maximum coat thickness 16 mm.


If the walls include existing render or the substrate isn’t line and level and requires dubbing out, the fixing lengths stated within this specification may need to change. This will need to be confirmed on site prior to the installation of the Wetherby system. Sizing of flashings, trims and beads may also require alterations. Where necessary dub out, using Wetherby Dubbing Render, any hollow or defective areas to leave a suitable surface for the application of the insulation boards.

WBS Biocidal Wash.

Guidance for specification option:

Treat areas of moss, algae and mould growth with WBS Biocidal Wash.

Where required, apply one coat of Wetherby Biocidal Wash to the entire surface by roller or knapsack spray and allow to dry. Brush the surface to remove all signs of growth before rendering commences.

WBS Stabilising Solution.

Guidance for specification option:

Dense smooth surfaces may require treating with WBS Stabilising Solution / Bonding Agent to ensure adequate adhesion on wet fix or render only applications.

Where required, apply one coat of Wetherby Stabilising Solution to the entire surface by roller, ensuring uniform coverage and allow to dry.

Support rails and brackets

-

Fixing method

-

Material

WBS Aluminium Base Rail.

Guidance for specification option:

Securely fix Wetherby starter track with profile clip above DPC level at base of the system. Mechanically fix starter track at max. 300 mm centres, 50 mm from each end. WBS 3756 base rail connectors should be used to join the tracks, packing shims may be required to ensure the starter track is true to line and level. Any gaps behind the basetrack allowing free air movement behind the insulation should be sealed appropriately.

Bracket fixings

WBS HIT 6/5 Hammerscrew Bead Fixing.

Insulation

-

Material

Stone wool insulation.

Guidance for specification option:

Thermal performance ranging from 0.036 Wm²/K. Thicknesses compatible with the system’s certification range between 50–250 mm.


  • Board size: 1200 x 600 mm.
  • Minimum compressive strength: 10 kPa.
  • Thermal conductivity: 0.036 Wm²/K.
  • Fire performance: Class A1 (BS EN 13501-1:2002).
  • Non-combustible.

 

Environmental:

  • CFC / HCFC Free.
  • Zero ODP.
  • GWP less than 5.

Manufacturer guidance

Insulation boards must be mechanically and adhesively fixed. Fixings specified are subject to pull out tests, wind load calculations and project requirements.

Adhesive

WBS Insulation Bedding Adhesive.

Additional mechanical fixings

SPIT ISO Range.

T-FIX-8M Range.

T-FIX-8S Range.

Manufacturer guidance

The fixings frequency, type and length would be subject to pull-out tests and wind load calculations. When using WBS fixings with the stone wool insulation, KWL washers must be used unless stated otherwise. 

Movement joints

-

Form with

WBS Stainless Steel Movement Joints.

WBS PVC Movement Joints.

WBS Stainless Steel Surface Mounted Render Stop Beads.

WBS PVC Surface Mounted Render Stop Beads.

Manufacturer guidance

All structural movement joints must be mirrored through the EWI System. As a minimum to incorporate the movement joints every 7–10 m vertically and at every other floor level horizontally. Structural Engineers will be required to confirm how much movement will occur and where movement joints are located in the substrate. 

Sealant

Compriband sealing tape must be installed between the insulation boards.

Render carrier or reinforcement

-

Material

Glass fibre reinforcement mesh incorporated into scrim adhesive.

Mesh size

-

Manufacturer guidance

50 m² Roll.

Fixings

DHM Range.

TID-MR Range.

Manufacturer guidance

Secondary mechanical fixings are required on all projects two storeys and above at a rate of 1 per m2 as per BRE Report BR135:2013. NHBC require in all cases that a minimum of one non-combustible fixing is installed through the reinforcement mesh per insulation board, in addition to other fixings. Install secondary fixings through the first pass of wet scrim adhesive and WBS Alkali Resistant Scrim Cloth. 100 x 100 mm scrim patches to be installed over each secondary fixing head. All fixing types, lengths and frequency subject to pull out tests and wind load calculations. Finally smooth out scrim adhesive using a spatula in preparation for the second pass of Scrim Adhesive.

Render

-

Material

Heck Silicone Primer.

Decorative finish

Heck Silicone Render Finish.

Guidance for specification option:

Mix and apply Wetherby Silicone Textured Finish strictly in accordance with the manufacturer’s printed instructions. The top coat should be applied with a stainless steel trowel to the thickness of the grain and finished with a plastic float. Apply in a continuous application always working to a wet edge and in the same direction to ensure consistency of finish. Wherever possible, entire elevations should be completed in a single operation to avoid joint marks in the finish. This can often be achieved by working to natural breaks in the building or working to breaks in colour or texture.

 

Do not apply Wetherby Silicone Textured Finish with differing batch numbers on the same elevation. Care should be taken to avoid texture changes at different levels. Prior to setting, polish render with plastic float to give an even texture and remove all trowel marks.

WBS Heck ED Mineral Render Finish.

Guidance for specification option:

Mix and apply Heck ED Mineral Render Finish strictly in accordance with the manufacturer’s printed instructions. The top coat should be applied with a stainless-steel trowel to the thickness of the grain and finished with a plastic float. Apply in a continuous application always working to a wet edge and in the same direction to ensure consistency of finish. Wherever possible, entire elevations should be completed in a single operation to avoid joint marks in the finish. This can often be achieved by working to natural breaks in the building or working to breaks in colour or texture. Prior to setting, polish render with plastic float to give an even texture and remove all trowel marks. Allow the Mineral Render to fully dry.

WBS Silicone Paint (For the Heck ED Mineral Render Finish).

Guidance for specification option:

Apply two coats of WBS Silicone Paint to the WBS Heck ED Mineral Render using a roller or brush as per the printed manufacturer’s instructions.

Colour

-

Manufacturer guidance

Any NCS or RAL reference; insert requirements.

Protective coating

Not required.

Aspira Render Protector.

Guidance for specification option:

Optional.


Apply Wetherby Aspira Render Protector with a roller ensuring a full and even coverage, covering 100% of the substrate. The substrate must be fully dry and clean before application; ensuring morning dew is not present on the substrate. Cross hatch application is recommended to ensure all areas are fully treated. Do not dilute product and protect from rain for a minimum 12 hours after application to allow coating to fully dry. 

System accessories

WBS Sealing Tape: Pre-compressed, expanding waterproof sealing tape.

WBS Firtree Fixings.

WBS Jointing Pieces.

WBS End Caps.

WBS EVO-STIK Silicone Sealant.

WBS Fire Rated Silicone Sealant.

WBS APU Bead.

Samples required

Submit samples of WBS Silicone/ Mineral Render for approval. Keep approved samples on site for the duration of the contract for inspection and comparison purposes.

Guidance for specification option:

The manufacturer offers a product sample service, providing a small sample of the finished build-up, colour and texture before a final decision is made. Contact the manufacturer for further information.

System completion

Inspection of completed installation

Documentation for insulated render systems

O&M manuals and data sheets relevant to the system installed

BIM objects

BOS

NBS BIM Object Standard

This BIM object has been authored to meet the requirements of the NBS BIM Object Standard.

Find out more about the NBS BIM Object Standard.

Platform Compatible Version
Revit
-

2

IFC
-

2

Third party certifications

European Technical Approval (ETA)

European Technical Approval (ETA)

Wetherby Heck European Technical Approval - 18_0229

Similar products from Wetherby Building Systems Ltd

Brick Slip Mesh System - Brick Slip System

Brick Slip Mesh System - Brick Slip System

Epsibrick External Wall Insulation System - PS1

Epsibrick External Wall Insulation System - PS1

Epsibrick External Wall Insulation System - PS2

Epsibrick External Wall Insulation System - PS2

Epsicon 3 - External Wall Insulation System - PS2

Epsicon 3 - External Wall Insulation System - PS2

Epsicon 3 - External Wall Insulation System - PS3 - External Wall Insulation Dash Finish

Epsicon 3 - External Wall Insulation System - PS3 - External Wall Insulation Dash Finish

Epsitec - Render Carrier Board – 7mm Brick Slips

Epsitec - Render Carrier Board – 7mm Brick Slips

Epsitec - Render Carrier Board – Silicone Render

Epsitec - Render Carrier Board – Silicone Render

Epsiwall External Wall Insulation System - PS2

Epsiwall External Wall Insulation System - PS2

KIWA Steel Frame Direct Fix Stone Wool - Stone Wool Insulation

KIWA Steel Frame Direct Fix Stone Wool - Stone Wool Insulation

Masonry – Silicone Render - Silicone Render System

Masonry – Silicone Render - Silicone Render System