EWI over large step in brickwork

Author details

Original Author:Admin Organisation:Retrofit Pattern Book

Detail summary

Detail showing woodfibre external wall insulation carried around a large brick projection on an external wall. Designed to ensure a consistent depth of insulation over the whole external wall ensuring a continuous thermal envelope.

Technical description

Plan Detail. EWI carrying round brickwork step. Single-brick or larger equivalent projection. Woodfibre insulation system.


Care should be taken to ensure air-tightness. Seal all service penetrations. Lap and tape all membranes.

All insulation to be continuous to avoid thermal bridging.

Preparation of external wall: Remove any existing loose material and prepare in accordance with manufacturer's requirements.

Any alterations to drainage and other fixtures, or work to prepare the substrate, to be agreed with contract administrator prior to work being undertaken. Prior to start on site inspect: form and condition of the structural substrate; institute repairs and/ or additional works necessary to make the substrate suitable to receive EWI system.

Parts list

  • EWI (Woodfibre) System With Rendered Finish [EW01]

    Composite woodfibre board for use on solid and hard to treat cavity walls.

    • Insulation back board: UdiTherm SK.
    • Insulation top board: Diffutherm NF (T&G, renderable).
    • Thermal conductivity: 0.045W/m2K. GWP 0.
    • Base Coat: levelling on substrate: 90% contact required around edge of boards between board and substrate to prevent thermal bypass. If substrate is very uneven, use base-coat material around edge of board to achieve contact.
    • Fixing: Fixed mechanically to substrate in accordance with manufacturers recommendations.
    • Render/carrier: to manufacturers standard.
    • Render: Udi Perl
    • Decorative finish: tbc
    • System guarantee: 25 years - ECO compliant insurances and guarantees.
    • System Certification : ETAG

    Unger-Diffutherm. Product Reference: UdiFRONT.
    Supplied by: Back To Earth. Tel: 01392 861763
    Web: http://www.backtoearth.co.uk/

  • EWI (Woodfibre) accessories [EW01]

    Corner reinforcement required for render over external corner.

    As EWI manufacturer.


  1. Admin - 2015-04-29 11:06:41 [Displayed version]

    Parts list updated.

  2. Admin - 2015-04-29 09:00:36

    DWG uploaded.

  3. Admin - 2015-04-29 08:59:34

    DWG uploaded. Back to earth contact added to EW01 part. Formatting changes.

  4. Admin - 2015-03-31 10:00:59

    Preview image and detail pdf updated to latest revision

  5. Admin - 2015-03-23 10:30:45

    Introduction revised for clarity, Technical description updated. Parts list re-formatted and updated with links.

  6. Admin - 2015-03-13 17:54:16

    Technical description updated. Parts list updated with relevant codes.

  7. Admin - 2015-03-11 17:37:47

    Parts list updated.

  8. Admin - 2015-03-11 17:37:05

    Parts list updated.

  9. Admin - 2015-03-11 17:36:14

    Version 5. Parts list updated with codes.

  10. Admin - 2015-03-11 17:07:26

    Preview image and pdf file updated with latest linetype colours and lineweights. Parts list updated.

  11. Admin - 2015-03-05 10:45:42

    Technical description updated.

  12. Admin - 2015-03-03 13:20:14

    Version 2. Original detail removed: information out of date/Superseeded. All details updated/replaced with latest revision.

  13. Admin - 2015-02-26 14:00:26

    First version

Leave a comment


  1. For those who have seen the Earth from space, and for the hundreds and perhaps thousands more who will, the experience most certainly changes your perspective. The things that we share in our world are far more valuable than those which divide us.

    User name

Leave a comment


A total of 14 users have left feedback about this detail.

Share your thoughts about this detail with other users:

Feedback summary

  • 80% of users found this detail easy to implement.
  • 50% of users found it easy to source skills for this detail.
  • 60% of users found this detail hard to understand.
  • 100% of users found the overall cost for this detail to be low.
  • 90% of users found materials for this detail easy to source.