As a key supplier to the roofing sector, Viking Roofspec spent much of 2022 developing a membrane roofing system that not only exceeds the new H1 (thermal efficiency) requirements, but does so while minimising cost and ensuring the thinnest possible insulation build-up.

For commercial projects, H1/AS1’s new insulation requirements depend on roof size and geography. All commercial roofs less than 300m² will require the roof assembly to have a minimum R-value of R6.6; whereas those greater than 300m² will depend on the climate zone they are located in. Working down the country, these minimums start at R3.5 in the northern regions and graduate up to R7.0 for the lower South Island. These changes have been designed to reduce the energy needed to heat and cool large buildings by an average of 23% compared to previous requirements.

Viking Roofspec has taken up the challenge of developing a warm roof system to not only: (i) fulfil H1’s new requirements, but (ii) address the cost concerns of the industry as well as (iii) the new design challenges that the new code brings. Engineer-tested in New Zealand by Holmes Solutions of Christchurch, Viking proudly launched ‘Viking WarmSpan²’ in November, 2022.

Viking WarmSpan² isn’t just a warm roof — it’s an entire structurally engineered roof build-up; designed from the substrate supports right up to the membrane surface.

With an R-value of R6.7, the WarmSpan² system can exceed nearly all new commercial roof R-value requirements in its current form without adjustment.* Featuring a 135mm thick PIR board (the thinnest R-6.7 build-up on the marketplace), WarmSpan² frees-up architectural constraints while saving construction time which, ultimately saves cost.

(*R7.0 for Central Otago and Southland can be achieved by using 145mm PIR board)

WarmSpan² has a spanning ability between substrate supports of up to 1.8m and 900mm for the steel tray and plywood substrate options respectively (versus the 400mm centred joists required under a heavy 17mm plywood substrate for a traditional membrane roof). This method, along with the heavily reduced nogging at the tongue-and-groove plywood edges, results in 3x less structural timber required by the building code — while still exceeding the structural requirements for snow loading.

Compatible with both Enviroclad and Torch-On membranes, the installation of Viking WarmSpan² mostly reflects that of its predecessor WarmSpan¹, meaning Viking’s Approved Applicators don’t need any new tools or training to install the new system to the professional standard expected by Viking Roofspec.