EWI to new door- Threshold and Head

Author details

Original Author:Admin Organisation:Retrofit Pattern Book

Detail summary

Section detail for external wall insulation fitted around a new replacement door with a new timber frame box surround. Door and surround installed as part of EWI installation works with insulation to reveal board and door frame.

The existing door threshold is reinforced with steel angle for structural support, with additional structural insulation over extruded polystyrene suitable for below ground insulation.

Technical description

Section detail. New door into EWI to external wall and opening. Threshold and head detail. Door to sit forward of existing door position within frame.

Reference Specification:

For guidance on access and step height for new doors and new or existing access openings: Please refer to Approved document M (Access to and use of buildings).

Based on specifications of door: Door facings: (laminate) to BS EN 438-1 and -7. Plywood: To BS EN 314, surface appearance to BS EN 636. Hardwood: To BS EN 635-2. Softwood: To BS EN 635-3. External wood matchboarded doors to BS 459. Wood framed panel doors Timber quality: To BS EN 942. All adhesives for for wood doors and frames to BS EN 204 for Polyvinyl acetate (PVAC). To BS EN 12765, class C4 for thermosetting resin.

Fire performance of all doors, Fire resistant doorsets and shutter assemblies: Type testing: To BS 476-22 or BS EN 1634-1. \ Smoke control doorsets and shutter assemblies: Type testing: To BS 476-31.1 or BS EN 1634-3 \ Intumescent seals: Type testing: To BS 476-23. Testing authorities to be UKAS accredited.

Single leaf external doorsets to dwellings, security: To BS 8220-1: General to BSI publication PAS 23-1, Specific req. to BSI publication PAS 24.

Safety glazing to door leaves and sidelights to BS 6206 for safety plastics and BS EN 12600 for safety glass. Location: To BS 6262-4. Please also refer to Approved document K for glazing to doors.

Perimeter insulation suitable for below ground use and drainage layer. To BS EN 13164

Cement: To BS EN 197-1 and CE marked.

Drainage layer: Granular infill free from excessive dust, well graded, all pieces less than 75mm in any direction, minimum 10% fines value of 50 kN when tested in a soaked condition to BS 812-111. In one layer no more than one of the following: Crushed rock (other than argillaceous rock) or quarry waste with not more binding material than is required to help hold the stone together/ Crushed concrete, crushed brick or tile, free from plaster, timber and metal. / Crushed non-expansive slag / Gravel or hoggin with not more clay content than is required to bind the material together, and with no large lumps of clay. /Well-burned non-plastic colliery shale. /Natural gravel. /Natural sand.


Care should be taken to ensure air-tightness. Seal all service penetrations through EWI and existing wall. Lap and tape all membranes around edges of EWI system.

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 the 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

  • Structural Insulation beneath door threshold [FAB EW06a]

    Structurally improved Polystyrene insulation beneath door threshold

    • Thickness: as per drawing. Depth as per drawing.
    • Width: as per door threshold.
    • Thermal conductivity: 0.04W/m2k. GWP: <5.
    • Joints: tight butt joints

    Compacfoam structural insulation. Product Reference: CompacFoam- 200

  • Rolled Support Steel Angles [FAB EW06a]

    • Manufacturer: Contractors choice.
    • Type: 65 x 50 x 5 mm rolled steel angle.
    • Finish as delivered:Hot dip galvanised to BS EN ISO 1461.
    • Spacing: at 1/3 points beneath door threshold.
    • Fixing: Mechanically fixed through compacfoam packer to existing masonry. Fixing to suit existing substrate.
    • Top-plate: Top-plate pre-fixed to upper end of angle to take load of threshold through compac foam insulation.

    Contractor's choice

  • EWI for ground level/within splash zone [EW01]

    Extruded Polystyrene (XPS) suitable for below ground conditions and for application of render.

    • Thickness: as EWI.
    • Depth: Minimum 300mm below internal floor level.
    • Thermal conductivity: 0.033W/m2k. GWP: <5.
    • Installation: Cut to fit around compact foam and steel supports to door threshold.
    • Joints: Tight butt joints

    BASF. Product Reference: Styrodur 2800C.

  • Insulated External Wood Flush Doorset [GD14]

    Enhanced EcoHomes Doorset.

    • Type: 54mm insulated single leaf door.
    • Target U-value : 1.0 W/m2K
    • Air-tight installation : Install to achieve maximum air-tightness, using appropriate air-tight tape and sealants at all junctions and potential air-leakage points. (expanding PU foam will not be sufficient to achieve adequate air-tightness).
    • Size: As existing.
    • Facings : Manufacturer's standard.
    • Glazing : Factory glazed as required.
    • Finish As Delivered : Factory finished paint system.
    • Ironmongery : Manufacturer's standard, factory fitted.
    • Threshold : Hardwood with mobility threshold seal.
    • Frame : Manufacturer's standard.
    • Handing : As existing.
    • Doorset Fixing : As manufacturer's recommendations.
    • Certification : All timber to be FSC certified.
    • Security : Secured by Design

    Performance Door Solutions. Tel: 01706 370001.
    Email: http://info@pdsdoorsets.co.uk.
    web: Performance Door solutions.
    Product Reference: Enhanced EcoHomes Doorset

  • Sealant To External Door Frames [GD14]

    Silicone, colour as contractors choice. Convex profile.

    Contractors choice.

  • External Wall Insulation (Woodfibre), 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/

  • Single-sided air seal tape [DP09a]

    Tape for junctions critical to air-tightness.

    • Location: see detail drawings - generally critical junctions for air-tightness. Size: 60mm (Single sided).
    • Accessories: ORCON F sealant and TESCON PRIMER RP (for use on rough/old surfaces to assist adhesion)

    Back to Earth: Tel: 01392 861763. Web: http://www.backtoearth.co.uk/
    Product reference: TESCON VANA/ TESCON PROFIL - 2 release tapes (single sided)

  • Softwood timber frame Boards [GD10]

    • Manufacturer: Contractors choice.
    • Type: Half round edge.
    • Finished size: to suit existing opening.
    • Species: Manufacturers standard.
    • Class: Class 2 to BS 1186-3.
    • Preservative treatment: not required.
    • Finish as delivered: Factory applied priming coat.
    • Fixing: Lost head nails at 30mm centres.
    • Certification: All timber to be FSC certified(or re-used from existing on site).

    Contractor's Choice.

  • Granular Backfill [EW01]

    • Material: 20 mm washed and graded aggregate providing 30% voids.
    • Minimum Thickness: As drawing.

    Contractor's choice


  1. Admin - 2015-04-29 10:30:14 [Displayed version]

    .dwg file updated.

  2. Admin - 2015-04-28 12:26:22

    .dwg file updated.

  3. Admin - 2015-04-28 12:20:50

    .dwg file updated.

  4. Admin - 2015-04-28 12:14:53

    .dwg file uploaded.

  5. Admin - 2015-03-31 09:54:05

    Granular backfill added to parts list. General error removal.

  6. Admin - 2015-03-27 16:05:00

    Preview image and .pdf file updated.

  7. Admin - 2015-03-23 15:43:51

    Technical description formatting changes. Parts list updated with links. Softwood boards added to parts list.

  8. Admin - 2015-03-23 15:42:43

    Technical description formatting changes. Parts list updated with links. Softwood boards added to parts list.

  9. Admin - 2015-03-12 16:23:42

    version 5. Technical description updated with Approved docs and British standards. Parts list updated with codes.

  10. Admin - 2015-03-10 13:48:54

    Parts list and intro/technical description updated.

  11. Admin - 2015-03-03 13:58:42

    Category updated. Parts list added.

  12. Admin - 2015-02-27 12:22:59

    Version 2 - .dwg uploaded

  13. Admin - 2015-02-26 17:02:56

    Title added and description

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