AIR VAPOUR CONTROL LAYER | AVCL

AVCL leakage membrane (Air Vapour Control Layer), also called 'wraptite air barrier' or 'housewrap' is mechanically attached an extra tough material providing good tensile and nail tear strength, designed for use as an air leakage barrier and vapour control layer (AVCL) for use in new build construction, renovation in timber-frame, steel-frame and masonry walls and floor applications requiring high moisture resistance. The product is manufactured by spinning strands of polypropylene and bonding them with heat and pressure to form a flexible scrim. When lapped, fixed and taped correctly, the product acts as an air barrier and can contribute to elements and junctions minimising heat loss by unplanned air infiltration and exfiltration. In fact, air barriers are intelligent types of vapour control layers as  they adapt to changes in humidity conditions. Like a vapour control layer, an air barrier prevents moisture from inside the building from entering the wall and insulation. The product is positioned on the warm side of the thermal insulation and held in place by staples to the background structure. Joints between adjacent sheets of the material should be lapped 100mm over a support and be sealed with a strip of double-sided tape. Airguard control layer is installed onto the internal side of the building envelope with the smooth side and logo facing into the building interior. As a membrane within a building’s wall or structure, an air barrier has the effect of resisting the passage of moisture from the internal, warm side of the wall. Installing an air barrier will control the flow of air and, by extension, the flow of moisture. Air Barriers ensure that the building envelope is properly sealed to control ventilation and prevent heat loss in compliance with Building Regulations Part L. Installed on the warm side of insulation, AVCLs protect insulates from interstitial condensation. While the vapor barrier prevents vapor diffusion, an air barrier prevents air leakage through differences in air pressure between the interior and exterior. Although vapour barriers and air barriers have a different method of managing the air and vapour, the result is the same: the protection of the insulation and wall structure from interstitial condensation. Air leakage membrane is easy to cut, lightweight to handle and usually comes in 1.5 x 50m rolls. Rolls of product are delivered to site in packages that carry a label bearing the marketing company’s name, the grade identification and the BBA logo incorporating the number of this Certificate. The product should resist the normal loads associated with construction and installation into a building.

AIR BARRIER MANUFACTURERS

When it comes to air leakage solutions, Novia® and Proctor® brands are the main players in the UK market. Proctor group offers Wraptite® UV membrane, an unique external airtight solution, which is not only highly vapour permeable, yet airtight – but also self-adhered to ensure a consistent airtight external seal. On other hand Novia comes with a VC200 Reflective Air-leak and Vapour Control Layer AVCL. The VC200 delivers improved thermal resistance ‘R values’, thermal transmittance ‘U values’ and helps to prevent interstitial condensation problems and boost the insulation performance. Both brands are followed by DuPont™ AirGuard® Control - superior mechanical strength product that can resist the loads associated with the construction of the wall or floor. DuPont™ AirGuard® Control may be also fixed to the external face of a cement bonded particle board, OSB or ply sheathing. As an alternative, either Low-E Insulation TAB 16 or Low-E SlabShield Reflective Foil Insulation VCL can be used. Further information may be found in our datasheet section.

PRODUCTS

• Novia VC2 Air-leak and Vapour Control Layer AVCL
• Novia VC4000 FR Reflective Air-leak and Vapour Control Layer
• Novia VC200 Reflective Air-leak and Vapour Control Layer AVCL 
• Wraptite UV
• Wraptite FZ (Floor Zone)
• DuPont™ AirGuard® Control
• DuPont™ Tyvek® HomeWrap® 
• Visqueen A2 Vapour Barrier 
• 3M™ Air and Vapor Barrier 3015NP
• ExoAir® 210AT