The H1 Roof - your solution to insulated roofing

The new H1/AS1’s schedule method aims to reduce the energy needed to heat and cool buildings by approximately 40%. To do so, the minimum R-Value of the building envelope needs to increase significantly. Although these new minimums will create more thermally efficient buildings, they will increase roofing costs significantly. This will restrict design with deeper ceiling cavities required for cold roofs, and higher parapets to obscure thicker insulation build-ups for warm roofs.

… Introducing Viking WarmSpan2   

Viking’s WarmSpan2 system is a fully-compliant, engineered warm roof solution that is the result of having analysed every possible component and installation method, to arrive at the most cost-effective; design-flexible; compliant; membrane warm roof assembly – that meets H1 (5th edition).

  • Proven structural system - engineered and tested by Holmes Solutions
  • The thinnest R6.7 roof assembly on the market
  • Structural supports 3 x less than traditional support requirement; with no compromise to structural integrity
  • Engineered to optimise the time required for installation
  • Compatible to all H1/AS1 climate zones
  • Installed only by Viking Licensed Applicators
  • 20-year product warranty
  • Full System Warranty Option: 20-years (conditions apply)

Quick Downloads

DJI 0187 R Min

Viking developed WarmSpan2 to answer the NZBC’s H1 (5th edition) requirements for doubling insulation values and the rising costs of construction. This engineer-tested system, exclusive to Viking Roofspec, saves cost on overall material and labour while providing an R-value of R6.7 within the lowest possible height build-up for an H1- compliant warm roof.

WarmSpan2 is a complete roof assembly with prescribed joist spacings and substrate-types included in its specification. Listed from the top-up, these are the system’s fundamental components:

  1. One of Viking’s CodeMark Membrane Systems (Enviroclad or Viking Torch-on)
  2. Coverboard
  3. Viking Insulated Plugs and Fasteners
  4. PIR – Rigid insulation panels (foil-faced PIR board)
  5. Self-adhered Vapour Barrier (Self-sealing SBS bitumen)
  6. 17mm T & G Plywood (H1.2 minimum treatment) or Steel tray substrate (ST7, ST900, or Metcom 7)
  7. Structural Supports (max. 900mm centres for ply substrate; 1800mm centres for steel tray)
Warmspan2 Plywood (Withjoists) ƒ SM

A Complete Roof

Design Flexibility

Being the thinnest-compliant-membrane assembly on the market at R6.7, WarmSpan2 has a thickness of only 146.4mm from the top of the vapour barrier to the underside of the membrane surface. This creates tasteful design lines by keeping parapets low. This system can be supported by either a plywood or steel stray substrate, and waterproofed by either of Viking’s CodeMark membrane systems; Enviroclad or Torch-On, offering more flexibility in design.

Time & Cost Savings

For WarmSpan²’s plywood substrate option, the roof build-up remains compliant with supports as wide as 900mm centres, reducing the labour and materials required, compared to E2/AS1’s 400mm maximum centres.

The tongue-and-groove ply negates the need for nogging on all sheet edges, further reducing labour and materials. The use of the same insulation plug and screw through the two separate layers: insulation (singular layer of 140mm PIR); and vapour barrier, removes the labour involved in applying individual adhesive and primer layers; let alone the savings rendered through reduced material handling.

Additionally, with the ply being an interior structural component, the moisture content doesn’t need to dip below 20% for the warm roof installation to continue while it dries; benefiting the construction programme.

Reduced Environmental Impact

WarmSpan² doesn’t require H3.2 treated plywood as a minimum. The use of H1.2 reduces the treatment process, creating better environmental benefits**.

We’ve removed the need for primers and adhesives on multiple layers, and with our PIR manufactured in New Zealand; along with Viking Roofspec having warehouses in Auckland, Wellington and Christchurch, we’ve reduced our carbon footprint through reduced logistics.

** H1.2 treated plywood is not readily available in the NZ market at time of system launch. In specifying a minimum standard Viking Roofspec is responsibly seeking all environmental and cost gains potentially available.