If you’re about to dive into an insulation project, then it’s essential to have a good understanding of R-value. You can use it to quickly make comparisons between the different types of insulation on offer. More importantly, you’ll be able to select a product that’s right for your needs. If you want to arm yourself with knowledge on this topic then keep reading. We’ve created the ultimate guide to insulation R-value in Australia. Let’s get started!

What does R-value mean?

The primary role of insulation is to regulate temperature and increase thermal efficiency. In other words, it needs to keep hot air out in summer and cold air out in winter.

Different types of insulation, like spray foam or batts, offer different levels of thermal efficiency. This is measured using R-value; it calculates the insulation’s effectiveness at resisting heat flow.

  • If you want to get technical, an R-value is calculated by dividing the insulation thickness (m) by thermal conductivity (W/mK).
  • For those who like to keep it simple, just remember that the higher the R-value, the better the heat transfer resistance.

What’s a good R-value?

An insulation’s R-value will fall somewhere between 1.5 and 7. Although insulation with an R-value of 7 will provide the best thermal efficiency, it may not be the best option for your project. The local climate will also influence insulation choice. In warmer climates like Western Australia, the highest R-value may be overkill.

The Australian Building Codes Board has set minimum insulation levels for building new homes. Locations throughout Australia have different requirements based on climate. In Perth, roof and ceiling should have a minimum R-value of 4.1 while walls require a value of 2.8.

Are there different types of R-value?

Three specific types of R-value help us to better understand the insulation’s efficiency during different times of the year.

Up R-value: Measures how well the insulation keeps heat from escaping the space. Warm air escaping is more of an issue in the colder months, which is why the up R-value is also referred to as the winter R-value.

Down R-value: Measures how effective the insulation keeps heat out during the warmer months. It is also known as the summer R-value. 

Total R-value: This is the sum of the up and down R-values. When you hear insulation providers quoting R-values, this is generally what they’re referring to.

Which insulation is best for R-Value?

Not only do different types of insulation have varying R-values, but each brand has its own specifications as well. In a “real world” environment, polyurethane spray foam insulation has a higher R-value than other options like foil insulation or fibreglass batts. That’s because it does such a good job of stopping airflow , effectively reaches hard-to-reach places and doesn’t degrade as as other insulation products do.

Does R-value decrease over time?

It is normal to expect insulation to suffer from wear and tear over time, which results in a lower R-value. Spray foam insulation is currently the most robust product available in Australia.

A major benefit of using this type of insulation is that it outlasts other products and maintains its R-value more effectively over the years. Practically speaking, that means you’ll enjoy consistently lower power bills for longer.

Whether you’re building a new structure or have existing insulation that’s reaching the 20-year mark, we suggest getting in contact with our team. We have highly experienced spray foam insulation providers who will complete the job to the highest standard.