Fibreglass Insulation is made from molten glass which has been spun into a fibre. Fibreglass batts are manufactured in widths of 430 mm and 580 mm to suit standard timber framing centres in walls or ceilings, and in a range of R- values from R1.5 - R4.0. Wall batts, with extra stiffening, are made especially for use in walls.

Rolls of Fibreglass Blanket in widths of 430 mm, 580 mm, and 1200 mm, and in lengths of 7 metres to 30 metres are also available. R-values of the blanket generally range from R0.6 - R2.4. The blankets are used for special applications such as cathedral ceilings.

Rockwool Insulation is made from molten basalt which has been spun into a fibre. The fibres are more dense than the glass fibres in fibreglass insulation, which means that rockwool has a higher R-value per unit thickness, and also has superior sound insulation properties. Rockwool insulation is generally more expensive than fibreglass, and is mainly used in domestic applications where a higher R-value is required for a particular thickness, or if better sound insulation is desirable.

Rockwool Batts are manufactured in widths of 430 mm and 580 mm to suit standard timber framing centres in walls or ceilings, and in a range of R-values from R1.5 - R3.0. Wall batts, and rolls of rockwool blanket in widths of 750 mm, and in 5 metre lengths, are also available.

Mineral Wool Batts and blankets also come with reflective foil insulation attached to one side. These are generally used in applications where better summer performance is desired, or where a vapour barrier is needed.

Mineral Wool Batts or Rolls are flexible and will compress in width to fit between timber framing at centres less than standard. They are easily cut with a sharp knife when necessary, and should be installed so that there are no gaps.

Concerns have been raised about the health safety of mineral wool insulation, some people claiming that it is like asbestos and causes cancer. However, asbestos fibres and glass fibres are structurally different, and the evidence available does not support the claims that the use of mineral wool insulations in homes will cause cancer.

The emphasis in Australia is to take sensible precautions during installation, such as wearing a face mask to reduce the inhalation of any fibre.

Sheep's Wool. Woollen batts are manufactured from sheep's wool which is felted into a batt or blanket. Generally waste wool is used, but in some cases more expensive batts are made from high quality wool.

Some manufacturers produce batts and blankets with different R-values, and others produce only the one R-value. Woollen batts are manufactured in widths of 430 mm and 580 mm to suit standard timber framing centres in walls or ceilings, with R-values generally in the range of R1.0 to R2.0.

When obtaining a quote from suppliers, it is important to ensure that the product will be of an adequate quality. The insulation should have been manufactured from wool which has been cleaned and scoured, and treated for vermin resistance (carpet beetles and moths), and rot proofing. The chemicals Vantoc CC 30 or Mitin FF are considered adequate for this treatment, but they must be applied during the last stage of wool scouring or at the blending stage of treatment. It is not adequate to spray these chemicals on prior to the insulation being installed. The insulation should have been tested to Australian Standard AS 15303, and performed adequately.

It is important that the Woollen Insulation is installed in a dry environment away from direct sunlight.