What is insulation?

Insulation can be made from glasswool batts or blankets, rockwool batts, natural wool, cellulose fibre, extruded polystyrene or expanded polystyrene boards, polyurethane foam, polyester fibres, and reflective foils.

Notably roof insulation is placed in direct contact with the roof sheets and usually comes with a reflective foil laminate adhered to the lower face.

Why is insulation required?

Insulation is used in order to reduce:

• Heating from the sun in summer
• Loss of interior heat in the winter
• Condensation on the inside of the roofing and walling
• Noise from rain, thermal expansion and contraction and other sources.

Note: Refer section 6.2 of the Australian Standard, SA HB 39:2015

Insulation must:

• Be as per the approved samples i.e. has correct R value, flammability, combustibility.
• Manufactured to AS/NZS 4859.1.
• Be undamaged with tears and holes through facing materials suitably sealed and repaired.
• Have no excessive sagging
• Be earthed if required
• Covered as soon as practicable after its installation, to prevent it being weather damaged.
• Have all joints sealed with a suitable tape to prevent air leakage when used as a vapour and air barrier.
• Ends appropriately trimmed and protected from weather, most notably at the ends of roof sheets terminating in a gutter.



In order to maintain the specified R value in a roofing system, the insulation may require the use of special brackets to prevent crushing at each support.