Mason UNI Flexible Air Barrier 2.74x50m2


SKU: UNI2.74x50 Category:


UNI is a Flexible Air Barrier (FAB?) that allows work to continue on the inside of the building without waiting for the cladding to be complete. This is due to UNI?s unique reinforcing and waterproof features.


  • Commercial and Residential construction
  • UNI is absorbent and can be used with all cladding systems.
  • UNI is strong and durable, suitable for all areas of New Zealand including up to ?Very High? wind zones of NZS 3604 and ?Extra High? over rigid wall underlays.
  • UNI performs over timber or steel framing.
  • UNI is suitable to be used as a non rigid backing for stucco plaster.
  • UNI is suitable as an air barrier on walls that are not lined. ? Vertical use only, not suitable as a roof underlay.

New Zealand Building Code Standard (NZBC)

The following tests have been carried out in accordance with NZBC Acceptable Solution E2/AS1 Table 23:

  • Tensile strength, edge tear resistance with AS/NZS 4200:2017;
  • Resistance to water vapour transmission in accordance with ASTM E96;
  • Resistance to water penetration in accordance with AS/NZS 4201.4:1994;
  • Surface water absorbency in accordance with AS/NZS 4201.6:1994;
  • Air resistance to BS 6538.3:1987;
  • Shrinkage in accordance with AS/NZS 4201.3:1994;
  • pH of extract in accordance with AS/NZS 1301.421s:1998;
  • Beal weather tightness test 112 a modification from AS/NZS 4284:2008 and E2/VM1.

Physical Properties

  • UNI is a 230gsm non-woven breathable synthetic flexible air barrier, reinforced by a fibreglass scrim.
  • UNI is water resistant and designed to provide temporary protection from weather conditions and UV exposure to timber framing without the installation of the cladding, which allows for the continuation of internal work on the house for 90 days after installation.
  • UNI has passed a water head test at 150mm at 48 hours! vs normal building wraps which are tested to a 20mm head of water at 24 hours.