R1.0 Wall Insulation


R1.0 insulation for walls

Reflective foil insulation is recommended in addition to bulk insulation products such as glass wool or polyester. Wall sarking can achieve ratings of up to R1.0 when installed with a minimum 25mm air space. This is known as a system R-value rather than a product R-value.


Foil face inwards or outwards?

In cooler climates Sisalation wall wrap is typically installed with the foil faced inwards. In the warm states the foil is faced outwards to reflect the heat of the sun. Use the correct wrap for your application – Sisalation wall wrap is not designed for use in roof spaces.


R1.0 Bulk Insulation

R1.0 bulk insulation is designed to keep heat and sound in and out of your home, or to contain it within certain parts of your home. Glass wool and polyester insulation batts consist of millions of tiny pockets of air which trap the heat.



R1.0 Insulation – the lowest rating

As a general rule, a thicker layer of thermal ‘bulk’ insulation (such as glasswool or polyester) will insulate better than a thinner layer of corresponding material. This is demonstrated when e.g. comparing the R-Values and corresponding thicknesses of some of the popular Autex Greenstuf polyester wall insulation batts, which are all made from different quantities of the same polyester material:

  • R1.0 – 75mm
  • R1.5 – 75mm or 90mm
  • R2.0 – 90mm
  • R2.5 – 90mm

Install Insulation at its Recommended Thickness

Insulation in wall will generally be installed between the wall joists. If however, space is limited it is better to reduce the R-value of the insulation to a thickness which can be installed without compressing the insulation. If the insulation becomes compressed within the cavity, it becomes less effective at insulating and it may also damage the plaster.

Hi-density wall insulation batts are often installed where the space becomes a limiting factor. These also come with acoustic (soundproofing) properties, which can also add value to the home, by reducing the amount of noise transfer between rooms and floors. Glass wool insulation batts can achieve a rating of R2.0 within a 75mm batt.