EWI to Flush Flat Roof with Gutter [Version ID #436]
Detail summary
Detail for external wall insulation to an existing flat roof with no additional insulation to the roof build-up. In order to cap EWI at top of wall and provide water runoff: a single piece stainless steel gutter provided. New membrane is then lapped over the EWI behind the existing roof overhang and fixed.
Technical description
Section detail, EWI to flat roof with gutter (to be replaced). No insulation work to existing roof.
Suggested Installation Sequence:
- Fix EWI to wall over existing fascia board.
- Install breathable roofing membrane above.
- Fix gutter above, under existing roofing membrane; taking care to ensure continuity with existing roofing membrane.
- Lap existing roofing membrane into gutter and make water-tight.
Reference Specification:
All guttering to BS EN 12056-3, clauses 3–7 and National Annexes. Collection and distribution of rainwater: Complete, and without leakage or noise nuisance.
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). 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 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
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Stainless Steel box Gutter [RF06g]
Flashing at junction between flat roof verge and external wall insulation. To BS 460, and BS EN 12056-3, clauses 3–7 and National Annexes.
- Manufacturer: Contractor's choice.
- Profile: As drawing.
- Gauge: 1.2mm min.
- Jointing: Joints to be avoided where possible. If required must be fully welded and tested. Could be glued and blind riveted subject to approval.
- Size: Contractor's choice- to suit existing roof dimensions and cover depth of external wall insulation. Ensure provides adequate capacity for rainwater discharge from roof.
- Finish as delivered: Self finished Stainless Steel grade 304.
- Setting out: To falls.
- Fasteners: as manufacturers recommendations.
- Accessories: As welded stop ends.
- Testing: Test on completion.
Contractor's choice
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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.
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Airtightness works to ceiling [DP03]
Seal all ceilings and repair any cracks in plaster to ensure no air-leaks.
- Location: All ceilings
- Product: Standard decorators caulk
Contractor's choice.
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Breather Membrane [RF06g]
Roof underlay. Sealed to phenolic foam insulation and dressed to drainage point at the end of each run of guttering to allow water to exit construction.
Green Building Store. Tel: 01484 461705.
Email: info@greenbuilding store.
Web: http://www.greenbuildingstore.co.uk
Product Reference: Solitex Plus -
Gutter support clip
Clip/ support to provide support for box gutter and provide fixing back to existing wall.
Contractor's choice/ Gutter manufacturers recommendation.
Revisions
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Admin - 2015-04-29 10:16:17
DWG file uploaded. General formatting changes. PDF file updated to latest revision
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Admin - 2015-04-29 10:14:49
DWG file uploaded. General formatting changes.
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Admin - 2015-03-27 16:23:29 [Displayed version]
Preview image and .pdf file updated.
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Admin - 2015-03-27 12:34:33
General formatting. Gutter clip, bretaher membrane, and Air tightness works added to parts list.
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Admin - 2015-03-23 16:17:09
General re-formatting.
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Admin - 2015-03-23 15:19:25
General re-formatting. Technical description updated with installation sequence. Parts list updated with suppliers links.
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Admin - 2015-03-12 12:01:07
Version 5. Parts list updated and errors removed.
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Admin - 2015-03-11 17:26:32
Parts list updated with codes
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Admin - 2015-03-11 15:09:46
Parts list added, technical description and intro updated.
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Admin - 2015-02-27 12:22:07
Version 2- .dwg file updated
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Admin - 2015-02-26 16:01:55
First version
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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.
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.
- Ease of understanding detail: Easy
- Ease of sourcing materials: Easy
- Ease of sourcing skills: Easy
- Ease of implementation: Easy
- Overall cost: Low cost
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User name
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.
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.
- Ease of understanding detail: Easy
- Ease of sourcing materials: Easy
- Ease of sourcing skills: Easy
- Ease of implementation: Easy
- Overall cost: Low cost
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User name
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.
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.
- Ease of understanding detail: Easy
- Ease of sourcing materials: Easy
- Ease of sourcing skills: Easy
- Ease of implementation: Easy
- Overall cost: Low cost
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.
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Discussion
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.
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