Masons UNI PLUS to replace UNI for added fire-retardancy.

Written by


18 October 2023


3 min read

Masons UNI PLUS takes over from the original UNI product to provide a fire retardant and secure, weather-resistant flexible air barrier on builds.

For years, Masons UNI Flexible Air Barrier range – UNI, UNI PLUS and UNI PRO – has provided weather protection, site security, and the ability to continue working inside even before the cladding is fixed.

Masons are phasing out the original UNI product and it is superseded by UNI PLUS, although we anticipate that merchants will still carry stock of UNI until mid-2024. 

UNI PLUS has all the benefits of UNI  – 90 days to complete interior works without the cladding in place - but has the added benefit of being Fire Retardant and has a white backing to allow more light to enter the building during construction.

UNI PLUS is installed in exactly the same way as UNI, using 40 Below Tapes, UNI Cap Nails, and Masons Penetration Seals and it has a current Codemark certificate of conformity.

Keeping construction moving

The UNI Flexible Air Barrier range of UNI PLUS and UNI PRO is a flexible polypropylene wall underlay system designed to provide temporary protection from weather conditions and UV exposure to timber framing for a minimum of 90 days (120 days for UNI PRO) after installation, allowing internal building work to continue.

‘Using UNI PLUS is a huge timesaver,’ says Ata Rangitauira from Arrowsmith Builders in Whakatāne. ‘We have used it on multiple builds and put it on as soon as we have the framing up. With the wrap installed, we can start working on the interior and pass inspections as we go, which is a big help.’

Along with providing the same 90-day UV protection as UNI, UNI PLUS is also fire-retardant under New Zealand standards for flexible wall underlays and may be used without restrictions.

Providing strength and security

Thicker and stronger than conventional building wrap materials, the multiple-ply structure of UNI PLUS and UNI PRO is a barrier to both air and water, while still allowing water vapour to diffuse, creating a drier, more comfortable environment inside and a more effective cladding system.

‘UNI PLUS is thicker than a normal house wrap, so it’s easier to keep nice and tight, and it looks good from the road,’ says Ata. ‘Also, it gives us security – if we haven’t got our windows in we just wrap straight over, so we don’t have to worry about break-ins when we’re off site.’

Strong and durable, UNI PLUS is suitable for all areas of New Zealand, including extra-high wind zones. Once installed, UNI PLUS ensures that weather won’t delay construction, helping to meet deadlines and avoid cost overruns.

‘We have been using UNI PLUS for about a year now. We do a lot of work for Kāinga Ora, which includes big renovation jobs, and sometimes we keep the Gib on the inside,’ says Ata. ‘We can have the UNI PLUS up for six weeks and it will ensure the Gib stays dry and prevents any weather damage. UNI PLUS is a fantastic product, and now we use it on every job we do. We think every builder should use it.’

Find out more

To learn more about UNI PLUS, visit  or call 0800 522 533 to speak to a Masons team member.