EWI to flashing at verge

Author details

Original Author:Admin Organisation:Retrofit Pattern Book

Detail summary

Detail for external wall insulation up to a pitched roof verge without sufficient depth to cover depth of insulation. To be used where it is not possible to extend the existing roof verge over the insulation, and so a new cap flashing must be installed at the junction between roof verge and external wall insulation.

Technical description

Section detail. EWI to existing pitched roof verge, with EWI extending beyond. Verge flashing added.

Reference Specification

New flashing and membrane to BS EN 10088-2 and BS EN ISO 9445-1 or -2. with sealant to flashing to BS EN ISO 11600.

Natural slates to BS EN 12326-1 and -2. Battens, counterbattens and ridge/ hip fixing battens Timber species: To BS 5534, clause 4.12.1. Fasteners to BS 1202. All breathable membranes under Slating to be Agrément certified. Bitumen sheet to BS8747 Annex B.

Battens, counterbattens and ridge/ hip fixing battens Timber species: To BS 5534, clause 4.12.1. Fasteners to BS 1202. All breathable membranes under Slating to be Agrément certified. Bitumen sheet to BS8747 Annex B.

For all works to existing roofs refer to Approved document C (resistance to contaminants and moisture), with reference to Section 2, and section 6.

Reference should be made to Document H (drainage and waste disposal). Approved Document F (ventilation) should be referred to with regards to ventilation to existing roofs and over eaves ventilation. Document L1b should be referred when working on existing dwellings, with particular attention to sections 5 and 6 regarding material alterations. Document L2b should be referred to with existing buildings other than dwellings.

Notes

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 existing verge to be agreed with contract administrator prior to work being undertaken. Prior to start on site inspect: form and condition of the existing roof and verge construction; institute repairs and/ or additional works necessary to make the existing construction suitable to receive EWI system.

Existing services

Rainwater Pipes and Waste Water Drainage: Rainwater pipes and waste water pipes will be moved to the outer face of insulation as standard, and swan-necked back into gulleys where possible. Any work additional to this should be agreed in writing with the contract administrator.

Windows: Where windows are to be replaced in insulation please refer to contract/window schedules for details. Where windowsare to be retained in insulation please refer to relevant detail drawings to show reveal insulation and cills.

Parts list

  • Stainless Steel Profile mini-parapet gutter [RF09b]

    To BS EN 10088-2 and BS EN ISO 9445-1 or -2. with sealant to flashing to BS EN ISO 11600.

    • Manufacturer: Contractor's Choice
    • Austenitic alloy grade 1.4301 (304).
    • Thickness: 0.4 mm.
    • Finish: Mill finished.
    • Fixing: Screw fixed over existing fascia board. Existing roof membrane lapped over.

    Contractor's choice.

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

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

    • Insulation back board: 100mm UdiTherm SK.
    • Insulation top board: 100mm 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/

Revisions

  1. Admin - 2015-05-01 09:20:06 [Displayed version]

    Title amended to match drawing

    |
  2. Admin - 2015-04-29 14:43:22

    DWG uploaded. PDF file amended to relevant drawing. Preview image updated.

    |
  3. Admin - 2015-04-29 14:42:46

    DWG uploaded. PDF file amended to relevant drawing.

    |
  4. Admin - 2015-03-27 16:59:05

    Preview image and .pdf file updated.

    |
  5. Admin - 2015-03-24 18:12:05

    General formatting. Introduction expanded. Technical description approved doc links expanded. Notes added. Parts list updated with suppliers links.

    |
  6. Admin - 2015-03-13 15:39:19

    Title updated to match drawing. Technical description expanded. Parts list updated with codes.

    |
  7. Admin - 2015-03-06 12:48:50

    First version

    |
Leave a comment

Discussion

  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


Feedback

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.