The Viking Warm Roof system underwent the ISO9705 'room test' to determine the Group Number classification required by the Building Code for the control of fire spread on interior wall and ceiling linings.  Achieving a Group 1S Fire Rating means specifiers can choose a Viking Warm Roof for a residential or commercial project, knowing that they are choosing a system with the highest possible fire rating.

The Viking Warm Roof system comprises of rigid polyisocyanurate insulation boards on top of which a waterproofing membrane is adhered.  Recommended membranes are Viking Enviroclad, which is a TPO membrane, or Viking Epiclad which is a wide-sheet EPDM rubber membrane.  Also called an 'outsulation', a warm roof insulates from the exterior of the building envelope, taking the dew point to the outside of the building.

It has been successfully installed on retail, commercial and cultural buildings, as well as residential homes.  The Viking Warm Roof can be used on new homes and buildings, but it is also the ultimate re-roofing solution as it can often be laid over the top of an existing roof, negating labour and waste management costs associated with uplifting an existing roof; let alone the avoidable cost and inconvenience of temporarily relocating building inhabitants. 

The fire test involved installing the Viking Warm Roof system on a steel structure located inside special test room, with a burner. The system consisted of 75 mm thick polyisocyanurate panels adhered with its specialised two-part polyurethane foam adhesive to the top face of profiled 0.55 mm BMT Zincalume steel roofing. The underside of the profiled steel sheet was exposed to the inside of the test room, with temperatures of up to 1000kW for 20 minutes.

The Group 1 rating was achieved as the heat release from the material did not exceed 1000kW within 20 minutes.

The ‘S’ in the rating refers to the Smoke Production Rate (SPR) which is averaged over 0 to 20 minutes and no more than 5.0 m2/s.The Viking Warm Roof system achieved 1.9 ms/2; thus comfortably achieving the Group Number 1-S rating.

Aside from fire rating performance, a Viking Warm Roof can offer energy efficiency; an easy re-roofing option; the highest possible R-value performance; structural integrity (as the rigid insulation strengthens the roof); and a clear roof cavity.  Additionally, only Viking licensed applicators can install them, resulting in a quality installation of Viking’s world class BRANZ appraised roofing systems – all issued with a robust 20 year warranty.