5th March 2026
Marking a year of Proctor Air® success
9th July 2025
The A. Proctor Group Ltd has been at the forefront of pitched roof membrane technology for more than a quarter of a century. Drawing on those years of experience, plus feedback from designers, specifiers and installers alike, 2024 saw us introduce a brand new underlay product: Proctor Air®.
The product was subsequently awarded a BBA certificate in May 2024. Now, a year on from that milestone, we look at how Proctor Air is shaping best practice in the UK pitched roofing sector.
Capable of being specified on all roof types – including those without low- and high-level ventilation, or without a vapour control layer – and accompanied by a 15-year warranty, Proctor Air is delivering peace of mind for new-build and retrofit projects, today and in the future.
How Proctor Air delivers pitched roof performance
As an air permeable, low-resistance (APLR) pitched roof underlay, Proctor air simplifies pitched roof constructions.
Its vapour permeability allows moisture vapour to escape the roof space, reducing condensation risk. Proctor Air has an Sd value of 0.015m and a vapour resistance of 0.075 MNs/g, making it one of the highest performing vapour permeable membranes on the market.
At the same time, its air permeability means no ventilation measures are required in cold roof spaces, as it provides a more uniform flow of air in the roof space than normal vents. Proctor Air also requires no vapour control layer in the ceiling, and nor does the ceiling need to be well-sealed.
Alongside air and vapour permeability, Proctor Air offers water holdout performance and wind uplift resistance that ensures it can cope with more frequent extreme weather driven by climate change. Pitched roof underlays provide secondary weather protection (the roof covering is always the primary protection), so they are water resistant – not waterproof.
Even so, Proctor Air offers a W1 resistance to water penetration classification, when tested to EN 13859-1. A hydrophobic additive in all three of its layers helps it to achieve a minimum of 1m hydrostatic head – a level of water resistance that meets the guidance of NFRC’s Technical Bulletin 6.
When Proctor Air is used on a roof featuring in-line solar PV panels surrounded by non-airtight tiles, the roof covering can continue to be treated as air permeable. There is no requirement for ventilation in the loft space below the underlay, or in the batten cavity above the underlay.
Verifying Proctor Air’s performance with BBA certification
Achieving BBA certification for Proctor Air one year ago provided specifiers and installers with independent third-party verification that our performance claims are genuine and accurate. Because an Agrément certificate assesses a construction product’s fitness for purpose, obtaining a BBA certificate for Proctor Air showed it had been tested and assessed in relation to its intended use.
Organisations like the A. Proctor Group, who have a history of technical innovation, rely on working with certification bodies like the British Board of Agrément to bring new ideas to the market. And during the NEWS Marking a year of Proctor Air® success process of Proctor Air’s certification, we enjoyed a collaborative relationship with the BBA.
Monthly meetings with our BBA project manager ensured we could keep each other updated on progress, and maintain ongoing dialogue about testing schedules and product sample needs. In addition to the performance characteristics described above, the Proctor Air BBA certificate also covers the following.
- When used with Proctor Air, solar PV panels can be treated in the same way as other impermeable roof coverings, including tightly-jointed slates and tiles, and metal sheets.
- Proctor Air is one of the very few membranes which can be used in wind zones 1-4 without additional measures such as taping joints or additional battens.
- Proctor Air achieves an excellent Mullen burst strength result (an assessment of the fabric’s strength), which helps it to “resist the loads associated with the installation of the roof.”
- Slip resistance has been assessed to ensure the health and safety of operatives as part of normal safe roofing practices. Proctor Air “has a high coefficient of friction, giving a slip resistance surface for increased safety during the installation of the covering.”
Proctor Air case studies
In its first year, Proctor Air has already been widely adopted by the UK pitched roof sector. Already, we have been able to produce a variety of case studies showcasing the underlay’s qualities in action.
Private house, near Dundee
Neil Simpson, a Partner at Wellwood Leslie Architects, fitted Proctor Air himself while renovating the roof of his stone-walled property built in 1902. He began to see the benefits of the new underlay even before he had completed the reroofing work.
As Neil observed, there are hundreds of properties in Scotland with roofs like his. That includes most of the village where he lives. “We need to make use of modern products and technology,” he said. Because Proctor Air provides consistent ventilation across the whole roof, Neil didn’t have to install plastic ventilation products that would have detracted from the traditional appearance of the property.
Situated in an exposed location overlooking the River Tay, the house is subject to the elements. As Neil has continued to live in the property during the work, the underlay had to be capable of protecting the property and its occupants.
“Proctor Air has been excellent,” explained Neil. “It is relatively easy to install, and has protected us from the weather. The wind used to whistle through the roof before, but we’ve seen a difference straight away in reducing that infiltration.”
Hatchmeadow apartments, Northumberland
This age-exclusive development, operated by the housing association Bernicia Homes, featured a T-shaped apartment building with a 2500m2 pitched roof, including several gables and valleys. Unfortunately, problems with the existing roof specification were causing some residents to experience leaks during periods of poor weather.
A significant challenge when working on the roof of any existing, occupied building is protecting the people inside the building without the full roof system in place. That challenge is multiplied when the building in question is large and work has to be carried out in sections over a longer period of time.
To address the issues once and for all, the existing roof was stripped back and a new system installed. The roof also included an area of solar PV panels, so the chosen solution had to be capable of providing weathertightness and condensation control in different circumstances across the single building – all while residents remained in occupancy during the work.
James Roy, Senior Quantity Surveyor at Wensley Roofing, described the replacement roof system as a “belt and braces” approach. “That made labour a challenge on the project,” said James. “But with the Proctor Air membrane in place, we were comfortable leaving it exposed for a couple of days if necessary, knowing that residents in the apartments below were still protected.”
Previously, residents had to use buckets to catch leaking water. Following installation of the new roof system, the leaks stopped – even during some periods of bad weather.
Read more: https://proctorgroup.com/projects/proctor-air-provides-peace-of-mind-for-apartment-residents-during-essential-reroofingworks
Manchester Town Hall renovation
The £325m scheme to redevelop the Grade 1-listed Town Hall is one of the biggest heritage projects in the UK. Known as the ‘Our Town Hall’ project, every aspect of the building is being restored.
Removing the roof finish has afforded the opportunity to install a new pitched roof underlay. As an historic building, the Manchester Town Hall roof features many intricate details. The complexity of the roof forms, combined with the age and heritage value of the building fabric, meant opportunities to provide modern roof ventilation were limited.
A key advantage of Proctor Air is that it removed the need for separate roof ventilation. By providing a more uniform flow of air in the roof space, it ensured there would be no ‘dead zones’ where the complexity of the roof form could otherwise have restricted air movement.
Proctor Air might be a modern product, but it is preserving the building’s heritage in its own way. When the weather-tight wrap and 3700 tonnes of scaffolding are finally removed from the Town Hall, the building and its users will benefit from reliable roof ventilation and condensation control.
Thanks to Proctor Air, the roof should be capable of facing Manchester’s changing weather and climate for another 150 years.
Read more: https://proctorgroup.com/projects/proctor-air-delivers-performance-for-the-future-in-historic-roof-as-part-of-prestigiousmanchester-town-hall-renovation
Construction trade press and award success
As a significant product development in the history of the A. Proctor Group, Proctor Air has unsurprisingly played a central role in the company’s industry communication over the last year.
The July 2024 issue of Total Contractor featured an FAQ article on Proctor Air and its BBA certificate. The following month, another series of FAQs dealt with the subject of water holdout in pitched roof underlays.
Episode 7 of The Proctor Podcast featured a conversation about the weather resistance of membranes; watch and listen here. An edited version of that conversation has appeared in RCI magazine, and has also informed articles in Total Contractor and Roofing Today.
Among other articles, we have discussed roof membranes for retrofit projects in RCI, and ventilation in complex roofs in Roofing Today.
All of this industry communication took place alongside an eye-catching advertising campaign that positioned Proctor Air as “the air to the throne.” Our hard work throughout 2024 culminated in a triumphant night at December’s Construction Marketing Awards (CMAs).
During a gala dinner and ceremony, held at the Hilton London Bankside, judges named the A. Proctor Group as winner in both the Best Product Launch category and the Best Advertising Campaign category.
Best Product Launch was awarded for the Proctor Air campaign. Recognising the challenges of introducing a new product into a very competitive marketplace, the judges noted how the “attention-grabbing, innovative campaign” communicated Proctor Air’s benefits, built momentum, and exceeded expectations in terms of return on investment.
In winning Best Advertising Campaign, the company was praised for its “really eye catching and different approach.” The unique digital art resonated with audiences and “was sure to grab attention,” while positioning the company as a trusted and expert partner.
What made the two wins particularly special was that we produced everything in-house. Our campaigns truly represented us as an organisation – credible, innovative and professional, while still bringing personality into our marketing. The success was made possible by the hard work, passion and innovative ideas of the A. Proctor Group team.
