REINFORCED VAPOUR CONTROL LAYER

Reinforced vapour control layer is a very strong, tough and durable, polyethylene-based vapour control membrane with a mono-filament reinforcement scrim for tensile strength in wall and roof installations for use within roof and wall constructions to prevent warm, moist air entering the building fabric and condensing within the insulation. Reinforced vapour control layer can be utilised where very high moisture vapor resistance is not a necessity but a strong, durable airtight membrane is. The woven, polypropylene, multifilament scrim reinforcement provides good resistance to tears and punctures. Unlike unreinforced barriers, reinforced vapor membranes are manufactured by laminating two layers of thinner membrane with a core of reinforcement mesh, normally multifilament PE. Varying performance characteristics can then be achieved by altering the reinforcement and thickness of membrane layers used, along with giving the option to include additional layers, such as foils, to further enhance the membranes performance. The reinforcement grid gives great strength and tear resistance, producing membranes which are robust and easy to install. A major issue with unreinforced vapor barriers is their tendency to puncture if snagged on a corner or a screw/nail during installation. As a single layer membrane, there is nothing to stop this small tear from ripping along the whole membrane leaving a gaping hole where moisture and air can move freely causing untold damage to the fabric of the building and reducing the energy efficiency of the system. Reinforced VCL comes in certain thicknesses such as 0.15mm, 0.29mm, 0.31mm, 0.37mm, 0.4mm or 0.5mm. While roll length is usually 50m or 100m long, widths may vary ranging from 1.5m, 1.6m, 2m to 3m. The higher the roll tensile strength is, the tougher the material is. The current highest tensile strength achieved by manufacturers is 5.8 kN/m. Rolls come in 3 main colors: blue (Novia SRTP and Visqueen), translucent (Proctor Procheck) and silver (YBS Foil-Tec VCL).

REINFORCED VCL MANUFACTURERS

The sheet may be translucent to ease the installation process and is the grade utilised by many leading system manufacturers such as Novia or Proctor Group. For instance Proctor Group Ltd has been chosen as a high performance vapor reinforced barrier for the new Passenger Terminal Building at Muscat Airport in Oman.

PRODUCTS

NOVIA SRTP

Novia STRP PRO AVCL is a high-spec strengthened and foil laminated polythene vapour-control membrane used in insulated wall, roof and floor applications, including warm flat roofs where high concentrations of moisture vapour need to be controlled. STRP PRO is a highly-durable tear-resistant membrane with an aluminium foil core which improves the insulation performance.

PROCTOR PROCHECK

Proctor Procheck Premier 500 is a strong reinforced polyethylene vapor barrier with good vapor resistance. The woven extruded polypropylene multifilament scrim reinforcing provides improved nail tear resistance. 

YBS Foil-Tec VCL

Foil-Tec provides additional strength and thermal performance over conventional vapour control layer material, and giving the added benefit of a service cavity. Foil-Tec is a multi-layer foil laminate coated with nitrocellulose to provide a corrosion resistant, highly reflective and robust vapour control layer insulation system.

VISQUEEN

Visqueen High Performance Vapour Barrier is a multi-layer reinforced polyethylene barrier with a 20 micron aluminium foil. The barrier is coloured blue on the upper surface and silver on the reverse. The product is supplied in single wound rolls (not folded), 2m x 50m long.

VCL INSTALLATION

Fix the vapour control layer strips horizontally (preferably from top to bottom) or vertically with inscriptions on the inside with pre-installed double-sided tape or, if the situation requires it, with a stapler. Cover the places where the vapour control layer is perforated by staples with adhesive tape. Further vapour control layer strips should be installed with a suitable overlap, which is printed on the membrane and bonded with single-sided or double-sided tape. The places where the vapour control layer connects to the wall should be sealed with special adhesive or butyl tape. It is recommended to use an additional hold down strip and to leave about 2 cm of excess foil. Seal all places where service lines pass through the vapour control layer thoroughly with special adhesive or adhesive tape.

Picture credit:https://visqueen.com/

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