Thermax Light Duty™ thermal insulation sheathing  distributed by DCTech is a non structural, rigid board consisting of a glass fibre reinforced Polyisocyanurate(PIR) thermoset foam core laminated between smooth, reflective aluminium foil facers on both sides.

Thermax Light Duty™ has a glassfibre reinforced PIRthermoset foam core, along with chemical modifications, contribute to improved fire performance and dimensional stability. The Thermax Light Duty™ PIR foam core will not melt, flow or drip when exposed to fire, instead it will form a strong char that prevents flame spread and further degradation to the core, unlike EPS (Expanded Polystyrene) which will spread the flame due to oxygen being held between the cells within the panel. The EPS cells are also a thermoplastic, which tend to melt and shrink under intense heat.

Thermax Light Duty™ PIR thermal insulation has bonded aluminium foil facers which serve as effective moisture vapour retarders. Thermax Light Duty™ PIR thermal insulation can be installed exposed to the interior without a thermal barrier which offers a high insulating value.

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  • Thermax Light Duty™ PIR is designed as a thermal insulation and interior finish system for walls and ceilings in metal, wood post frame, and concrete or masonry buildings


  • Durable white acrylic-coated aluminum on one side, embossed aluminium on the other for light-impact areas
  • It can be pressured-washed up to 6,894.7 kPa with a 15-degree or greater spray tip


  • Thermax Light Duty™ PIR thermal insulation is manufactured with a zero ozone depleting potential. The use of Thermax Light Duty PIR thermal insulation helps reduce the carbon footprint of commercial buildings.

Specification clause – Soffit

  • Dow Thermax Light Duty Soffit Board should be described in specifications as:–The soffit insulation supplied by Dynamic Composite Technologies shall be modified PIR (Polyisocynurate) Dow Thermax Light Duty Soffit Board ___mm thick CFC/HCFC–free, rigid modified PIR thermoset insulation core with autohesively bonded 35 μ embossed pure foil facings on both sides, conforming to AS fire tests, AS1530–3, AS3837 Group Classification 1, AS ISO 9705: 2003 Group 1 ceiling only, Group 2 walls and ceilings, FM 4880, manufactured to the highest standards under quality
    control systems approved to ASTM C1289-02 by Dow Building Solutions and shall be applied in accordance with the instructions issued by them.