1 min read. This article looks at the key differences between bulk insulation and reflective insulation.

Thinking of installing insulation in your home? Perhaps, you are researching and beginning to see all the different options available? We get it. There’s a bit to digest. Insulation is not a one size fits all product. Thankfully, we are here to help.

Understanding the different categories that insulation sit within, is a good place to start.

The two main categories of insulation used within Australian homes are Bulk Insulation and Reflective Insulation. The difference between these two categories lay in how they respond to heat.

Firstly, let’s take a quick look at the different ways in which heat is transmitted.  After that, we will look at the different properties of the two.

There are 3 forms of thermal energy transference – conduction, convection and radiation.


3 forms of heat transfer

Share this Infographic On Your Site!

Bulk Insulation

Bulk insulation is made of low-density material. As a result, it acts as a resistant barrier to heat flow. It is this barrier that prevents heat from transferring through objects. This transference of thermal energy as mentioned above, is the process of conduction. By design, bulk insulation has millions of pockets of still, trapped air.  It is this trapped air which gives this type of insulation its thermal properties. Bulk insulation products include expanded polystyrene boards, polyester batts or glass wool batts. These products are designed to fit in between joists in walls and floors to stop the flow of air.



Reflective Insulation

As the name suggests, reflective insulation reflects radiant heat waves.  Foil insulation is a common reflective insulation product used in the Australian market.  Foil insulation on its own, doesn’t have an inherent R-value as bulk insulation does. In order for reflective insulation to work effectively, it requires a layer of trapped air of at least 25mm. This is why you commonly find that it needs to be bought in combination with bulk insulation to get the maximum effects of thermal efficiency. Additionally, foil insulation must be kept clear of dust and dirt. It needs to remain clean to be able to reflect radiant heat effectively. This is what makes it a good choice for roof and wall insulation. However, for underfloor insulation, bulk insulation products are best.


 More about EXPOL Underfloor insulation

Cleverly engineered for maximum thermal performance, EXPOL fits snugly between the joists of suspended timber floors. EXPOL is a rigid insulation board. As a result, it won’t sag over time like other underfloor insulation products in the market. Sagging insulation creates gaps, which reduces the thermal performance and efficiency.  Sagging insulation also creates nice warm pockets for furry little creatures! The unique design of EXPOL allows for installation within existing homes, and new home builds. Additionally, EXPOL is a DIY product that is easy to install, saving you $$ on expensive installation costs.

Find out if EXPOL underfloor insulation is right for your project.