Between them, Masons’ Enviro AAC Intertenancy Wall System and UNI PLUS Flexible Air Barrier from Masons help keep construction on budget, and on schedule.

For Russell Thomas, owner of R & R Homes in the Bay of Plenty, building homes for new buyers and existing homeowners looking to upsize — or downsize – requires an absolute focus on costs and efficiency to achieve the greatest value for his customers.

In a recent six-unit development in Papamoa, the combination of the Enviro AAC Intertenancy Wall System and UNI PLUS Flexible Air Barrier from Masons allowed him and his team to maximise construction efficiencies and retain more control of the project.

For the last ten years, Russell has regularly used Masons’ Enviro AAC Panel for exterior wall cladding. Cost-effective and quick to install, Enviro is a strong, lightweight exterior cladding panel.

"When we started this new multi-unit development, we needed an intertenancy wall system that provided excellent acoustics and fire performance," explains Russell. "I’ve used tilt-up slabs before, but that was an expensive option for mid-market residential. I was looking for something cost-effective that we could control without using third parties. I did the research and really liked the look of the Enviro AAC Intertenancy Wall System."

IT Wall — fire-rated for compliance

Masons’ Enviro AAC Intertenancy Wall System is based on the 50mm thick Enviro AAC (autoclaved aerated concrete) panel. This dense yet lightweight material is fully NZBC compliant for both fire resistance (scoring a rating of 120/120/120 on walls up to 10m high) and sound transmission (STC), with a lab performance of 64 dB — higher than the minimum STC requirement of 55 dB for intertenancy walls. See the Masons website for full details.

"One of the reasons we chose it for this project is because most of the fireproofing is in the panel, not the ancillary fixings," says Russell, "and it gives us more flexibility in pipework and wiring placement compared with concrete block or tilt slab. In some of the other systems, it’s more difficult to access those services."

Ultimately, Russell’s choice of the Enviro system was a product of function and economy. "Anything you can fully control is always going to save you money — you’re not having a third party come in, so you don’t have to give away margin and you’re in control of the programme on a significant part of the building’s structure."

Easy multi-storey installation

Another structural advantage of Enviro is the ability to run a continuous intertenancy wall up through both levels of the duplex units. "You’ve got a c-channel in the middle, then there’s a 20mm gap between the framing and the panel, which is fixed using four Masons proprietary brackets. The panels are then mortared together, so you’ve basically got a solid concrete wall."

The system can be installed up to three stories continuously, without interruption, by as few as two builders, and installation can flow around other work on site. Masons also provide on-site training through site visits during construction, bringing their expertise to all aspects of the job.

Keep working inside before cladding

"Our Masons rep is a great guy, and he came to site one day to bring the boys smoko," says Russell. "He looked at the building wrap we’d used and said, 'Why aren’t you using our product?' That was the UNI PLUS wrap. I looked at the cost compared to the one we traditionally use, and the cost was somewhere between 20 and 30 per cent lower."

"I didn’t know much about the wrap, because when you’re a builder sometimes you get set in your ways. I did the research and changed over, and I was very happy with my change. I'll be using UNI PLUS for my future projects."

UNI PLUS Flexible Air Barrier is a fire-retardant flexible wall underlay that gives early enclosure to builds, allowing work to continue inside for up to 90 days without waiting for the cladding to be complete.

"Once you have UNI PLUS fixed in place, and you get all your flashings and weather tape on and lock in the windows, it’s all waterproof. I can have GIB on the walls and painters in while I’m finishing off the cladding," says Russell. "It gives you the ability to really punch on with the job — it just makes so much sense to use this wrap."

"I’m happy with all the Masons products, and definitely recommend them. I’ve actually got another intertenancy build in the pipeline, and they’ll be the first things I draw on the plans."

Talk to our helpful team

Visit the Masons website: mpb.co.nz to learn more or call 0800 522 533 to be put through to your local Masons Rep.