Controlling sound transfer between units is a major design challenge in multi-unit dwellings, especially when working with timber-framed intertenancy walls.

The Masons 50mm Enviro AAC Intertenancy Wall System is designed to address this challenge by focusing on the fundamentals of acoustic control: mass and separation.

"Based around the Enviro autoclaved aerated concrete (AAC) panels, our solution supplies the physical mass needed to deaden sound," says Arthur Whitfield, Masons Technical Manager. "The system can be installed continuously up to three storeys, making it practical for multi-residential builds."

Sound control through separation

With a working density of 650 kg/m³, the 50mm Enviro panels are about a quarter the weight of traditional concrete. Their porous structure, combined with panel mass, helps dampen mechanical vibration and naturally absorb sound frequencies.

The panels are installed between two timber-framed walls with air gaps and secured with lightweight aluminium brackets. "This minimises sound transfer by physically separating the structures," says Arthur. "The result is greater privacy, improved wellbeing and what we call the “quiet enjoyment” of a home."

The finished wall assembly achieves an STC rating of 64 — well above the minimum STC requirement of 55 for intertenancy walls, making homes built with the Enviro system more desirable for prospective buyers and tenants.

In addition to its acoustic advantages, the system also exceeds fire performance requirements under the New Zealand Building Code, with a rating of 120/120/120 for walls up to 10 metres in height.

Simple to install, built to perform

Designed with site conditions in mind, the Masons Enviro AAC Intertenancy Wall System is straightforward to install and construction-friendly. It typically requires only two builders and does not need weather protection during installation.

"That’s another big advantage of AAC panels," says Arthur. "They don’t have to be kept completely dry while waiting to be installed. Builders really appreciate how forgiving and practical this solution is."

As an alternative to high-end plasterboard-based systems, the Enviro panels offer a simple system with excellent sound reduction, helping to create quieter, more liveable homes in multi-unit developments.

Talk to our helpful team

For more information about the Enviro AAC Intertenancy Wall System including installation and compliance documents, visit mpb.co.nz or call 0800 522 533 to speak to one of our team.