Weather Defence™

Weather Defence™; is a rigid air barrier used behind façade cladding systems to regulate the indoor environment. It has transformed building envelope construction and performance.

Weather Defence™; is an excellent air control barrier which helps to regulate the indoor environment by restricting heat gain or loss via uncontrolled air movement through the wall.

Follow the installation instructions in the Weather Defence™; manual to create a weathertight barrier that can be left exposed to the elements so work can continue on the interior.

With attention to detail, Weather Defence™; installations can achieve air tightness targets that contribute to a building’s energy efficiency and allow any glasswool insulation in the cavity to perform as intended by avoiding wind washing.

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Further information


  • Weather Defence™ is suitable for enclosing a building to provide a solid weathertight barrier that forms part of the external façade system.
  • Due to the high vapour permeability of Weather Defence™, moisture can escape from the wall cavity when used with a vented or ventilated façade system.
  • This controls the risk of condensation build-up causing damage within wall spaces.
  • This risk is higher in colder climates which is why the National Construction Code requires building membranes to have a Class 4 vapour permeance in Climate Zones 6, 7 and 8.
  • No additional wall wrap or sarking may be needed.


  • Rigid air barrier with Class 4 vapour permeance
  • Can be exposed to weather up for 12 months
  • Enclose buildings faster so the interior fitout can start sooner

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