Roof insulation to flanking wall in room-in-roof [Version ID #84]
Detail summary
Roof insulation detail for loft insulation to flanking wall of room-in-roof or a storage space in roof.
Insulation to upright stud walls between room-in-roof and loft space. Insulation in plane of rafters where existing roof membrane is non-breathable. Need to ensure adequate ventilation behind insulation.
Technical description
Section detail. Loft insulation. Room in roof, insulation to existing with impermeable sarking.
Insulation to upright stud walls, in plane of rafters where existing membrane non-breathable. Where possible access stud walls from behind through existing loft access. Otherwise create new insulated loft access hatch.
Loft insulation increased to 400mm depth - recycled formaldehyde free glass fibre loft roll with breather membrane topping to reduce thermal bypass. In cases of existing insulation: inspect for damage, leave in-situ if in acceptable condition and overlay with new insulation.
Parts list
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Insulation Boards/Batts Between Studs (flanking wall)
Glass mineral wool semi rigid batts. \ Thickness: 200 mm. \ Thermal Conductivity : 0.034W/m2K. \ Friction fitted between studs and held in place by polyester webbing stapled between studs. (Where existing studs are <150mm, fix additional insulation bats to back face of studs to prevent cold bridging.) Ensure insulation is continuous with loft insulation to prevent thermal bypass and cold bridging.
Knauf \ Reference: Earthwool Universal Slab
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Vapour Check/ Air-tightness Membrane
Intelligent vapour check membrane, to prevent thermal bypass and improve air-tighness, whilst avoiding risks of summer condensation. Fix to back of existing studwork wall and timber studs using appropriate adhesives/tapes, taking care especially to seal at junction with celingin joists/ floor - a high risk area for heat loss from void between joists in floor of room in roof.
Green Building Store \ Reference: Intello Plus
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Insulation Boards/Batts Between Rafters
Formaldehyde Free Glass mineral wool semi rigid batts friction fitted between rafters. \ Thickness: 35mm less than rafter depth. Width to suit rafter spacing. \ U-value: 0.032 W/m2k. GWP 0.
Knauf \ www.knaufinsulation.co.uk \ Reference: DriTherm Cavity Slabs.
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Loose laid loft insulation
Flexible formaldehyde free glass mineral wool. \ 85% (minimum) to BS EN ISO 14021. \ Thermal Conductivity : 0.040 W/mK. \ GWP 0. \ Insulation cover should be even and continuous, right to the eaves. Ensure meets any eaves insulation and/or internal wall insulation to prevent cold bridge at eaves without blocking any ventilation paths required to loft space/ roof space.
Knauf \ www.knaufinsulation.co.uk \ Reference: Knauf Earthwool loft roll 40
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Breather Membrane/ wind-tight layer
Membrane, laid over top of loft insulation to prevent thermal bypass - joints to be lapped and taped.
Tyvek \ http://construction.tyvek.co.uk/Tyvek_Construction/en_GB/products/wall/housewrap.html \ Reference: Tyvek Housewrap
Revisions
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Admin - 2015-06-25 14:04:06
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Admin - 2015-04-30 13:16:15
Minor title amendment - change of " wall in room..." to "wall of room..". Intro summary updated.
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Admin - 2015-04-30 10:49:24
DWG and pdf file updated. General formatting changes. Polyester webbing added to parts list.
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Admin - 2015-03-30 11:17:58
Preview image and pdf detail file updated.
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Admin - 2015-03-28 18:00:27
RF05b amended in parts list
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Admin - 2015-03-17 17:16:25
Introduction expanded. Technical description updated with BS codes and approved docs. Parts list updated and amended
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Admin - 2015-03-17 17:12:43
Introduction expanded. Technical description updated with BS codes and approved docs. Parts list updated and amended
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Admin - 2015-03-04 13:35:17 [Displayed version]
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
-
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.
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