Floor insulation to cover joists [Version ID #249]
Detail summary
Floor insulation detail for shallow/thin joists, with rigid insulation beneath to cover joists and improve airtightness.
Technical description
Section detail. Floor insulation for suspended timber floor. Insulation between and covering joists.
Section detail. Floor insulation between joists with breather membrane below. Accessible from below. To achieve target U-value of 0.2W/m2k.
SUGGESTED INSTALLATION SEQUENCE:
Preparation: Inspect sub-floor and timbers for signs of damp and rot. Before starting work carry out a survey of any structural timbers, particularly those which enter external walls (e.g. floor joists). Record current condition of timbers and moisture content for future reference.
Remove any organic matter from sub-floor and floor void. Ensure all existing air-bricks are unobstructed with clear ventilation path
1.) Check floor void for signs of rot and damp report immediately if found. 2.) Remove below floor obstructions take particular care to remove organic matter eg. timber pieces. 3.) Seal joists/gaps between floor boards from above or below. Ensure all gaps in floorboards are filled. 4.) From below: ensure gap between floor and skirting is sealed with tape/membrane. 5.) Fit insulation butts between joists. 6.) Install rigid board insulation. 7.) Plaster finish to underside of rigid insulation board.
Before start of works: Inspect any structural timbers, particularly those which enter external walls (e.g. floor joists); Inspect sub-floor, and timbers within for signs of damp and rot. Report immediately if any found. If possible record current condition of timbers and moisture content for future reference. Remove any organic matter from sub-floor and floor void. Ensure all existing air-bricks are unobstructed with clear ventilation path
REFERENCE SPECIFICATION:
Please refer to Approved documents: B (fire safety): B1 section 1 (material alterations)/ B2 section 3 (internal fire spread), and Appendix A (material properties). Document A (structural safety) should be referred to when fixing/applying loads to existing floor joists or members. Ensure existing joists meet requirements in Approved document A (structural) before starting works. Refer to Doc L: Section 5 of L1B for dwellings; including all relevant amendments.
Parts list
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Rigid woodfibre insulation fixed across joist. [FL01d]
Woodfibre insulation. Thickness: to create total 200mm insulation thickness under floorboards/floor finish (Rigid woodfibre + woodfibre between joists should=200mm min.). Thermal conductivity: .004W/m2K. GWP 0.
Unger \ www.unger-diffutherm.de \ Reference: udiUnger-Diffutherm NF, or udiUnger-Diffutherm L.
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Woodfibre Insulation Between Floor Joists [FL01d]
Flexible woodfibre insulation. \ Depth TBC on site based on depth of existing joist. \ Friction fit between joists to ensure air-tightness (batts cut approx 20mm wider than opening between joists.) \ Thermal conductivity: .004W/m2K. GWP 0.
Unger \ www.unger-diffutherm.de \ UdiFLEX flexible wood fibre insulation.
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Seal between floorboards/floor edges. [DP02] & [DP04]
Draught-proof and seal all timber floors to ensure no air-leaks. Draughtproof neoprene strips between floorboards. Standard decorators caulk to wall/floor junctions and skirting boards /OR: additional draughtproof strips.
Draughtex. \ www.draughtex.co.uk \ Reference: Draughtex Neoprene Strips. \ Reference: Decorators caulk- contractors choice.
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Single-sided air seal tape [DP09a]
Tape for junctions critical to air-tightness. 60mm (typical). \ Accesssories: ORCON F sealant and TESCON PRIMER RP (for use on rough/old surfaces to assist adhesion)
Pro Clima \ http://www.greenbuildingstore.co.uk/page--pro-clima-airtightness-tapes-options.html \ TESCON VANA/ TESCON PROFIL (2 release tapes)
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single/ two coat board finish plaster [IW02]
Plaster or render finish directly to Rigid woodfibre insulation.
Contractors choice.
Revisions
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Admin - 2015-04-30 13:26:33
Introduction/summary updated to include references to undercroft/cellar as per title.
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Admin - 2015-04-30 11:13:07
Reformatting changes. DWG file uploaded.
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Admin - 2015-03-30 11:10:07
Preview image and pdf detail file updated.
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Admin - 2015-03-30 10:53:22
DP09a amended for use on "joints of Rigid insulation board". Plasterboard part removed.
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Admin - 2015-03-26 13:51:36
Removed reference to Approved document H.
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Admin - 2015-03-26 13:26:49
General re-formatting. Introduction revised. Technical description updated with approved docs and additional notes.Parts list updated with supplier links.
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Admin - 2015-03-17 10:29:21 [Displayed version]
Introduction updated, Technical description expanded. Parts list revised with relevant codes.
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Admin - 2015-03-04 15:54:25
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
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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.
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