Masons Intertenancy Wall System

Product Description

A simple and flexible acoustic and fire-rated wall system based on tried-and-true materials for faster construction.

The Masons Intertenancy Wall System is based on our Enviro AAC (autoclaved aerated concrete) panels – a dense yet lightweight material with proven acoustic and fire-stopping performance. The system is easy to work with, giving builders workflow flexibility and construction efficiencies. It is fully NZBC compliant for both fire resistance (FRR) and sound transmission (STC).


Multi-unit residential, terrace houses, apartments, aged-care facilities, commercial.

The Enviro™ AAC panel

The Masons Intertenancy Wall System is based on Masons Enviro™ AAC panel – a 50 mm thick panel tested to and compliant with AS/NZS1530.1. It is manufactured from cement, sand, lime and water which is aerated with an expanding agent. Soft blocks are moulded from the mixture and then sliced into the required panel size and cured in a steam pressure autoclave for up to 12 hours.


  • Fully FRR & STC compliant
  • This system meets and/or exceeds the New Zealand Building Code’s minimum requirements for both fire resistance rating and sound transmission class. It scored a rating of -/120/120 for walls up to 10 m high. FRR -/120/120 fotimber frame, and -/90/90 for light steel framing. Acoustic engineers Marshall Day reported a lab performance of 64 dB – higher than the minimum STC requirement of 55 dB for intertenancy walls.


  • Easy to use, flexible and fast
  • The Masons system is construction friendly and designed for simplicity and flexibility. As few as two builders can install the system, and installation can be flowed around other work on-site. No weather protection is needed for the AAC panels when work stops, making on-site storage simple.


  • Designed for buildability
  • The system can be installed up to three stories continuously, without interruption, and there is often no need for extra accessories or fiddly work at mid-floors junctions. Services can be run down the framing on either side of the AAC panels, and materials be carried in smaller parts when site access is difficult. The ACC system is easier for everyone on the job. 

* Penetrations to the Masons Intertenancy Wall System: fire and acoustic must be engineered for fire rating and to preserve acoustic performance and installed by suitably qualified persons. 

Scope and limitations
For scope of use, limitations, conditions and statement of building code compliance, refer to the Masons Intertenancy Wall System pass™.