Product Attributes
DuPont AirGuard Control, air leakage vapour control layer is satisfactory for use as a vapour control layer/air barrier in new build construction and renovation, as an alternative to more traditional materials.
Further information is given in BRE report (BR 262 : 2002) Thermal insulation : avoiding the risks.
Where constructions need to comply with NHBC Standards specifiers should observe the requirements of that document.
It is essential that proper care and attention is given to maintaining the product’s integrity and continuity.
Walls in new buildings should be designed and constructed in accordance with the relevant recommendations of the UK National Annexes of BS EN 1996-1-1 : 2005 and BS EN 1996-2 : 2006.
Existing walls must be in a good state of repair with no evidence of rain penetration, damp or frost damage.
Suspended concrete and suspended timber ground floors incorporating the product must include suitable ventilation.
Practicability of installation
The product can be readily installed by operatives experienced with this type of product.
Risk of condensation
The risk of condensation occurring will depend upon the properties and vapour resistance of other materials used in the construction, the internal and external conditions, and the effectiveness of the product’s installation.
The product can contribute to meeting the relevant requirements of the national Building Regulations:
England and Wales — Requirement C2(c)
Scotland — Mandatory Standard 3.15, clauses 3.15.1 and 3.15.5
Northern Ireland — Regulation C5.
Consideration must be given in the overall installation to minimising penetrations by services. Joints at ceilings / walls must be sealed to offer significant resistance to water vapour transmission. Sealing should also be carried out in accordance with the Certificate holder’s instructions.
Air permeability
When lapped, fixed and taped correctly the product is considered to be an air barrier and will contribute to elements and junctions minimising heat loss by unplanned air infiltration. Guidance in this respect can be found in:
England and Wales — Accredited Construction Details (version 1.0)
Scotland — Accredited Construction Details (Scotland)
Northern Ireland — Accredited Construction Details (version 1.0).
Strength
The product will resist the normal loads associated with installation of the wall or floor.
Properties in relation to fire
The product will melt and shrink away from heat, but will burn in the presence of a naked flame. The product is classified in accordance with EN 13501-1 : 2007 as a Class E material.
In walls, cavity barriers should be used to satisfy the requirements of the national Building Regulations.
Maintenance
As the product is confined within a wall or floor structure and has suitable durability (see section 11), maintenance is
not required. Any damaged areas should be repaired or replaced before completion in accordance with section 15.
Durability
The product is rot proof, does not tear easily and will have a life equal to that of the building in which it is installed.
Tyvek AirGuard Control - Product Installation
Tyvek AirGuard Control is installed on the internal (warm) side of the roof or wall insulation to form a continuous barrier against air leakage and water vapour transfer. A spacer batten between Tyvek AirGuard Control and the internal lining is recommended to prevent damage to the membrane from electrical sockets, light fittings, etc. The batten space will also provide a services void for electrical cables.
The membrane may be laid either vertically or horizontally as appropriate. Laps between each sheet should be 100 mm minimum and sealed with Tyvek Butyl Tape, Tyvek Tape or compressed under the batten. Tyvek AirGuard Control should be pulled taut across the surface and secured with non-ferrous felt nails or staples as follows:
• Horizontal centres = max 600 mm
• Vertical centres = max 300 mm
Tyvek AirGuard Control can be installed either before or after the windows and doors are fitted, provided that the membrane is sealed at the window/door frame position. Airtightness around the details can be achieved by compressing Tyvek AirGuard Control under a timber batten or by sealing to the frame with Tyvek Butyl Tape. Proprietary tapes or sealants should be used when installing the windows and doors to maintain overall airtightness.
Tyvek is laid horizontally over the entire roof surface, parallel with the eaves and secured with non-ferrous felt nails or staples as follows:
Horizontal centres = max 600 mm Vertical centres = max 300 mm
Overlap the Tyvek sheeting by 15 cm.
Laying unsupported
Lay the Tyvek underlay directly over timber members, pull it taut to create a minimal drape.
Laying supported
Lay the Tyvek underlay directly onto timber boarding or insulation and fix timber counter battens over.
Scottish sarking
Lay the Tyvek underlay directly onto open-jointed timber boarding and fix with galvanised clout nails. Lay the slates over the Tyvek underlay in direct contact.
The overlap at the ridge should be at least 300 mm.
Overlaps, pipe penetrations, roof window junctions and other details can be further secured with Tyvek Tape.
Connections to other surfaces eg. masonry should be made with Tyvek Butyl Tape.
Any damage that occurs in Tyvek should be repaired using Tyvek Tape.
Fully supported
The product may be used over sarking boards of softwood (cold ventilated roofs), and either with continuous insulation or insulation placed between the rafters (warm roofs).
The product is either secured to the support with counter battens at least 12 mm thick to create a drainage and vapour dispersal space between the product and the tiles or, when using timber sarking, the traditional Scottish practice with the tiles or slates fixed directly into the boards. This space should be ventilated in accordance with BS 5250 : 2002 when using tight fitting roof covering.
Counter battens, when used are fixed with corrosion-resistant staples or galvanized clout nails as appropriate. Tiling battens are secured to the counter battens and support fixings. Alternatively, the membrane may be installed draped over counter battens, with sufficient drape to allow drainage of liquid water under the tiling battens.
Care must be taken to minimise the risk of interstitial condensation as described in section 6.5 particularly for timber sarking which may be below the dew-point for extended periods during winter months.
Unsupported
The product, when installed as an unsupported system, is fixed in the traditional method for roof tile underlays, ie draped between the rafters.
Repair
Damage to the product can be repaired easily prior to the installation of slates or tiles by replacing the damaged areas, by patching and sealing correctly. Care should be taken to ensure that the water-tightness of the roof is maintained.
Finishing
Detailing of abutments, verges and hips must be in accordance with the Certificate holder’s instructions.
The tiling and slating must be carried out in accordance with the relevant clauses of BS 5534 : 2003, BS 8000-6 : 1990 and the tile/slate manufacturer’s instructions, especially when using tightly-jointed slates or tiles.
Damage
Any damage or service breaches in Tyvek AirGuard Control caused by pipe penetrations, etc. should be made good with Tyvek Tape