These instructions should be read in conjunction with local standards AS 3999 or NZS 4246 and all applicable local, state and federal building regulations.
Before you start installing, please make sure you are familiar with our Health and Safety Message.
Ensure that you use tools and equipment that are suitable for the intended application. This will include suitable safety equipment.

Do not start work until the site is safe!

Assess the ceiling condition and structure together with the method of installation you are to use based on the appropriate requirements established in the building code, site assessment and or plans provided. Installation must be completed to the requirements of relevant standard: AS 3999:1992 or NZS 4246:2006.


  • Sharp knife for trimming insulation.
  • Ladder.
  • Suitable clothing (see our Health and Safety message).
  • Tape measure.
  • Non-conductive insulation stick for positioning insulation in hard to reach areas.
  • Kneeling board to span ceiling framing.

Install instructions

  • Determine the width of insulation needed by measuring the typical distance between ceiling joists.
  • Determine the maximum thickness of insulation that can be installed by subtracting 25mm from the depth of the available cavity.
  • When installing the insulation, ensure that you achieve a snug fit avoiding any gaps.
  • Butt insulation firmly against both the top plate of the wall at the bottom and the ridge joist at the top of the cathedral ceiling.
  • Do not push the insulation completely into the joist cavity. The front face of the segment should be flush with the face of the ceiling joist, leaving at least a 25mm airspace between the insulation and the underside of the roof deck.
  • Do not compress insulation or block ventilation. Please consult with your local codes and practices to determine the required ventilation and ventilation baffle requirements in cathedral ceiling applications.
  • When installing insulation into existing cathedral ceilings where roofing material is required to be removed, please refer to local or state authorities as specific requirements around the removal and replacement of roofing materials may apply.