GENERAL
Cross-reference
General: Read with A90 General technical requirements.
PRODUCTS
Insulation
Blown mineral fibre loft insulation: To BS 5803-2. Blown cellulose fibre loft insulation: To BS 5803-3.
Mineral wool insulation boards, batts, rolls and slabs (MW): To BS EN 13162. Expanded polystyrene insulation boards (EPS): To BS EN 13163.
Extruded polystyrene insulation boards (XPS): To BS EN 13164. Polyurethane insulation boards (PUR): To BS EN 13165. Cellulose fibre insulation blown between studs: To BS EN 13171.
Breather membrane
Standard: To BS 4016.
EXECUTION
Eaves roof ventilators for existing roofs
Eaves free air space: Not less than required by Building Regulations for ventilation of roof space.
Insulation batts or quilt laid between ceiling ties/ joists
Installation requirements:
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Joints: Butted, no gaps.•
Extent of insulation: Over wall plates.•
Service holes: Sealed, and debris removed before laying insulation.•
Eaves ventilation: Unobstructed.•
Electric cables overlaid by insulation: Sized accordingly.•
Water cistern platforms on ceiling joists: Insulation below omitted. Mineral wool installation: To BS 5803-5.Insulation batts or quilt laid across ceiling ties/ joists
Installation requirements:
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Insulation widths: Widest practical.•
Laid direction: At right angles to ties/ joists.•
Joints: Butted, no gaps.•
Insulation: Fitted neatly around rafter ends and extended over wall plates.•
Service holes: Sealed, and debris removed before laying insulation.•
Eaves ventilation: Unobstructed.•
Electric cables overlaid by insulation: Sized accordingly.•
Water cistern platforms on ceiling joists: Insulation below omitted. Mineral wool installation: To BS 5803-5.Insulation boards or batts fitted between rafters
Installation requirements:
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Joints: Butted, no gaps.•
Fasteners: Used where necessary to retain insulation and/ or prevent slumping.•
Eaves ventilation where required: Unobstructed.•
Air space above insulation where required: Unrestricted.Faced mineral wool insulation fitted between rafters
Installation requirements:
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Fixing: Secure, with facing on warm side, staple flanges at 300 mm centres to underside of rafters.•
Joints: Closely butted, no gaps. Seal at ends of lengths with adhesive tape.•
Eaves ventilation where required: Unobstructed.•
Air space above insulation where required: Unrestricted.Polyurethane foam sprayed between rafters
Blown loft insulation
Installation: In accordance with BS 5803-2.
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Installer: Trained by the insulation manufacturer. Installation requirements:•
Service holes: Sealed, and debris removed before laying insulation.•
Eaves ventilation: Unobstructed.•
Electric cables overlaid by insulation: Sized accordingly.•
Water cistern platforms on ceiling joists: Insulation below omitted.Loose laid loft insulation
Installation requirements:
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Insulation: Level, covering all parts of the ceiling.•
Service holes: Sealed, and debris removed before laying insulation.•
Eaves ventilation: Unobstructed.•
Electric cables overlaid by insulation: Sized accordingly.•
Water cistern platforms on ceiling joists: Insulation below omitted.Insulation to loft access hatch
Installation: Cut to fit with no gaps and securely fixed.
Edges of hatch: Sealed with an approved compressible draught excluder.
Insulation to existing water cistern
Mineral wool products: Installation to BS 5803-5. Cistern position: At ceiling level directly over joists:
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Sides and top of cistern: Covered with insulation.•
Continuity: Continuous with loft insulation, no gaps. Cistern position: At high level:•
Sides, top and bottom of cistern: Covered with insulation.•
Continuity: No gaps.Fixing: Securely to prevent slumping/ displacement but without undue compression. Insulation to lid: Extended over side insulation and removable with lid.
Cellulose fibre insulation blown between wall studs
Installation requirements:
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Openings for hose: Submit proposals of locations.•
Service holes: Sealed, and debris removed before commencing insulation.•
Electric cables overlaid by insulation: Sized accordingly.Insulation sprayed between wall studs
Application: In accordance with Agrément Certificate. Installation requirements:
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Service holes: Sealed, and debris removed before commencing insulation.•
Electric cables overlaid by insulation: Sized accordingly.•
Residual material: Removed before fixing wall lining.Insulation boards or batts fitted between studs
Installation requirements:
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Fixing: Secure, friction fitted between studs.•
Joints: Closely butted, no gaps.•
Fasteners: Used to prevent slumping/ displacement.Faced mineral wool insulation fitted between studs
Installation requirements:
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Fixing: Secure, with facing on warm side, flanges stapled at 300 mm centres to face of studs.•
Joints: Closely butted, no gaps. Ends of lengths sealed with adhesive tape.Mineral wool insulation fixed to backing wall
Installation requirements:
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Joints: Closely butted, no gaps.•
Cladding supports: Fitted tightly between and around.Unfaced mineral wool insulation suspended vertically in timber frame separating wall
Installation requirements:
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Joints: Closely butted, no gaps.Unfaced mineral wool insulation fitted between studs in timber frame separating wall
Installation requirements:
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Fixing: Fit tightly with joints closely butted, no gaps.•
Fasteners: Used to prevent slumping/ displacement.Mineral wool insulation laid between floor joists
Installation requirements:
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Joints: Closely butted, no gaps.•
Service holes: Sealed, and debris removed before laying insulation.•
Electric cables overlaid by insulation: Sized accordingly.Mineral wool insulation supported between suspended ground floor joists
Installation requirements:
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Support: 20–25 mm square mesh polyethylene net draped over joists and stapled to sides of joists.•
Insulation: Laid on net between joists, no space between top surface and underside of flooring.Vapour control layer
Fixing to timber studs, joists or framing:
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Moisture content of timber: 20% (maximum).•
Method of fixing: Staples at maximum 250 mm centres along all supports. No sagging. Fixing to metal framing: Double sided sealant tape. Prime substrate as necessary.Fixing to concrete/ masonry: Prime and apply adhesive recommended by membrane manufacturer. Installation requirements:
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Setting out: Continuous, minimum joints, no sagging.•
Lapped joints: 150 mm (minimum), at supports only.•
Openings: Lap over and fix to reveals.•
Joints and edges: Sealed using double sided tape with vapour resistivity not less than the vapour control layer.•
Penetrations: Sealed.Breather membrane
Installation requirements:
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Setting out: Continuous. Form a barrier preventing water, snow and wind blown dust reaching the substrate.•
Lapped joints: 100 mm (minimum) horizontally and 150 mm (minimum) vertically.•
Openings: Lap over and fix to reveals.•
Bottom edges: Lapped over flashings, sills, etc. to allow free drainage to the exterior.•
Penetrations: Sealed.Flexible cavity barrier
Installation requirements:
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Spacing: Subdivide void into areas to comply with Building Regulation requirements.•
Fixing: Secure, with no gaps, to provide a complete barrier to smoke and flame.Sleeved Mineral wool small cavity barrier
Installation requirements:
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Fasteners: Staples at 150 mm (maximum) centres.•
Vertical barriers: Fixed by both flanges.•
Horizontal barriers: Fixed by upper flange only.•
Joints and intersections: closely butted, with barriers compressed along full length to give complete seal.Wired mineral wool small cavity barrier
Installation requirements:
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Fasteners: Staples at 150 mm (maximum) centres, fold if necessary to ensure a tight fit.•
Joints and intersections: Butted, no gaps.Mineral wool slab cavity barrier
Installation requirements: Continuous, with minimum joints.
Ventilated cavity barrier