Skip to main content

Appraisal number: 635 (2019)

Date issued: 23 May 2019

PRIMAflex™ Cavity Wall Cladding System


The PRIMAflex™ Cavity Wall Cladding System is a cavity-based, monolithic sheet wall cladding. It is designed to be used as an external wall cladding system for residential and light commercial type buildings where domestic construction techniques are used.

The PRIMAflex™ Cavity Wall Cladding System consists of PRIMAflex™ sheet, which is a fibre-cement sheet product, fixed over timber battens to form the cavity. The cladding joints are finished with purpose-made jointers or timber battens, and the system is finished with a latex paint system.

The cladding incorporates a primary and secondary means of weather resistance (first and second line of defence) against water penetration by separating the cladding from the external wall framing with a nominal 20 mm cavity.


The PRIMAflex™ Cavity Wall Cladding System has been appraised as an external wall cladding for buildings within the following scope:

  • The scope limitations of NZBC Acceptable Solution E2/AS1 paragraph 1.1.
  • Constructed with timber framing complying with the NZBC.
  • With a risk score of 0-20 calculated in accordance with NZBC Acceptable Solution E2/AS1 Table 2.
  • Situated in NZS 3604 wind zones up to and including extra high.

The PRIMAflex™ Cavity Wall Cladding System must only be installed on vertical, flat surfaces (except for tops of balustrades and parapets, which must have a minimum 5° slope and be waterproofed in accordance with the technical literature).

The PRIMAflex™ Cavity Wall Cladding System is appraised for use with aluminium window and door joinery that is installed with vertical jambs and horizontal heads and sills. (The Appraisal of the PRIMAflex™ Cavity Wall Cladding System relies on the joinery meeting the requirements of NZS 4211 for the relevant wind zone or wind pressure.)

Technical literature

  • PRIMAflex Cavity System Technical Specification, version 2
  • PRIMAflex Cavity System Installation Detailing, March 2019 

Consenting instructions

Always refer to the Appraisal in full and the technical literature.

Appraisal holder

Hume Cemboard Industries Sdn Bhd

Marketer details

Independent Building Supplies
Phone: 09 574 0324