IWI to curved bay [Version ID #614]
Detail summary
Detail for internal wall insulation fixed to the inside face of a curved bay. Designed to retain the character of the existing curved face without compromising the thermal efficiency of the building envelope.
This internal wall insulation system uses an intelligent membrane to regulate vapour diffusion. The membrane should continue across intermediate floors, ensuring continuous insulation, vapour-control and air-tightness.
Target U-Value: 0.3W/m2K
Technical description
Plan detail. IWI to curved bay window. 95mm Mineral wool IWI buildup and vertical supports.
Before starting work: undertake study of form and condition of existing walls and likely resistance to penetrating damp; log requirement of any repairs and/ or additional works to both internal and external condition necessary before installation of new system -e.g. re-pointing or repairs to external render. Internally: Before starting work carry out study of form and condition of the existing walls; draw up schedule of fixtures, finishes and fittings to be removed/relocated in order to install the internal wall insulation system. Attention to be paid to mechanical and electrical services (e.g. radiators, light switches). Refer to detail drawings for treatment of potential cold bridges (e.g. window reveals). All timbers: Before starting work carry out inspection of any structural timbers which enter the wall to be insulated (e.g. floor joists). Report any signs of damp or rot to contract administrator immediately. Record current condition of timbers and moisture content for future reference.
Suggested Installation Sequence:
Before installation: Remove all timber fixtures: Skirting, Picture Rails, Dado Rails etc. Remove curtain rails. Remove electrical socket/ telephone/cable socket outlets. Scabble surface to perforate paint (create lost of small holes with appropriate tool) and remove all wall-paper etc. Re-fix/renew all removed once insulation complete. Entire area installed with internal wall insulation to be finished with Gypsum plaster.
Installation:
- Assess existing wall and remove plaster if necessary.
- Move any existing services etc.
- Cut channel 2/3 into rigid board at intervals required to achieve radius (thickness of circular saw blade).
- Install IWI.
- Plaster.
Reference Specification:
All Expanded polystyrene insulation (EPS): To BS EN 13163. All fixings manufactured in accordance with BS1210. Mineral wool (MW): To BS EN 13162; reaction to fire rating to: BS EN 13501-1
All vapour control layers/ air tightness layer to durability requirements of EN 13984.
Please refer to Approved documents: Part B (fire safety): B1 section 1 (material alterations)/ B2 section 3 (internal fire spread).
Refer to approved document C (resistance to contaminants and moisture) with reference to the condition of internal walls before application on IWI.
Documents L1b of Part L (conservation of fuel and power) 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 iWI and existing wall. Lap and tape all membranes around edges of IWI system.
All insulation to be continuous to avoid thermal bridging.
Parts list
-
Internal Wall Insulation System (95mm thick) [IW02a]
Water repellent glass mineral wool slab to BS EN 13162.
- Thickness 95mm.
- Target u-value: 0.3W/m2k.
- Thermal conductivity: 0.033W/m2k/ 0.130W/mk.
- GWP<5.
- Fixing and supports: In accordance with manufacturer's recommendations.
Knauf insulation Ltd.
Product Reference: ThermoShell Internal Wall Insulation System (Requires: EcoStud for solid wall uprights.) -
Vapour Control Layer [IW02]
Intelligent breather membrane.
- Fixing: Laps And Edges: Sealed with vapour-tight adhesive tape.
- At junctions with party/partition walls, lap under insulated plasterboard.
- At floor and ceiling junctions ensure membrane is appropriately sealed.
- Pro-clima.
Reference: Intello membrane
- Knauf Insulation Ltd.
Thermoshell Vapour Control layer.
-
Single layer plasterboard backings [IW02a]
Plasterboard backings. Nail fixed.
- Manufacturer: Contractors choice.
- Plasterboard: wallboard
- Thickness: 15mm.
- Edge profile:Tapered.
- Fixing: Nail fixed to Manufacturers recommendations.
Contractor's choice.
-
Two coat Board finish Plaster
- Manufacturer: Contractors choice.
- Extent: whole system.
- Plaster: Gypsum bonding plaster
- Surface preparation: Tape joints.
- Undercoat thickness: As manufacturers recommendations.
- Final coat: Gypsum finish plaster.
- Final coat thickness: 2-3mm applied one coat.
- Finish: Smooth.
Contractor's choice.
-
Insulated supports IWI system [IW02]
Vertical supports for IWI batts. Thermally engineered composite of high performance extruded polystyrene bonded to Oriented Strand Board 3 (OSB 3)supports to IWI sheets. Expanded polystyrene insulation (EPS): To BS EN 13163.
Knauf insulation Ltd.
Reference: EcoStud for Solid walls.(Used in conjunction with Earthwool EcoBatt.)
Revisions
-
Admin - 2015-04-30 09:11:51
General formatting changes. Dwg file uploaded.
| -
Admin - 2015-04-30 09:11:15
General formatting changes. Dwg file uploaded.
| -
Admin - 2015-04-30 09:09:27 [Displayed version]
General formatting changes. Dwg file uploaded.
| -
Admin - 2015-03-30 11:53:06
Preview image and detail pdf updated.
| -
Admin - 2015-03-26 16:43:29
Changed references to "EWI" to "IWI".
| -
Admin - 2015-03-26 16:18:58
General re-formatting. Introduction expanded with additional detail. Technical description updated with BS codes and approved documents, additional notes added. Parts list updated with suppliers links.
| -
Admin - 2015-03-16 15:20:09
Technical description updated. Errors in parts list removed.
| -
Admin - 2015-03-16 13:55:05
Version 3- Parts list updated with codes.
| -
Admin - 2015-03-16 11:38:49
Technical description, parts list updated.
| -
Admin - 2015-03-03 16:00:35
First version
|
Feedback
A total of 14 users have left feedback about this detail.
Share your thoughts about this detail with other users:
-
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
-
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
-
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.
- 90% of users found materials for this detail easy to source.
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.
User name
Leave a comment