Foam Insulation vs Fibreglass Insulation - Which Insulation is Best for My Home?

Whether you’re building a new home or renovating an existing home, insulation is one of the most important factors to get right from the beginning of the project. The right insulation will keep you comfortable year-round, improve your home’s energy efficiency and save you money on your power bills. Fibreglass insulation and foam insulation are two of the most popular products on the market. But which one is right for your home? In this guide to fibreglass insulation vs foam insulation, we compare the two insulating materials for Australian homes. By weighing up factors like R-Value, longevity and cost, we’ll help you make the best choice for your project.

Fibreglass insulation vs foam insulation

Fibreglass insulation

Fibreglass insulation, also known as glasswool insulation, is made from glass that is melted down and spun into long fibres. It’s a type of bulk insulation that works by trapping thousands of tiny air pockets between the fibres. These air pockets break up the flow of heat, slowing down heat transfer. Fibreglass insulation is used all over the world as a reliable and high performing thermal insulation. It’s most commonly sold as rolls or batt insulation, and comes in a range of thicknesses depending on the R Value you need. Fibreglass or glasswool also has excellent sound proofing properties. For projects where reducing sound transfer is a priority, you can use specialised acoustic insulation batts. Find out more: How does fibreglass insulation work?

Foam insulation

Foam insulation is typically made from polystyrene or polyisocyanurate, and can have an open-cell or closed-cell structure. The most common closed-cell foam insulation products are made from extruded polystyrene (XPS) or expanded polystyrene (EPS). Foam insulation products are generally quite thin for the R Value they can achieve. They typically have high compressive strength and excellent resistance to moisture. Foam insulation is commonly sold as rigid panels, boards or rolls of flexible wrap. Some products combine a foam core with reflective foil facing which helps manage radiant heat. Foam boards are not the same as spray foam or expanding foam insulation. Check out our guide to expanding foam vs insulation batts for more information.

Which is better foam insulation or fibreglass insulation?

Both foam insulation and fibreglass insulation are highly versatile and reliable insulation materials. They are both suitable for residential use in hot, cold and temperate climate zones across Australia. Overall, neither is better than the other. However, one might be a better choice for your project, depending on the particular application and what you’re wanting to achieve. Below we compare fibreglass vs foam across a number of different categories.

Performance / R-Value

Both fibreglass and foam are high performing insulation products that will improve energy efficiency and indoor comfort. Foam products can typically achieve a higher R-Value for a given thickness. Fibreglass insulation is available in a wide range of R-Values from R1.5 to R7.0.

Cost

Fibreglass batts tend to be cheaper per m2 compared to foam insulation. On average, fibreglass batts cost $6-$10 per m2, while acoustic batts cost $10-$18 per m2. Foilboard rigid foam board insulation starts from $8 per m2, while reflective foam wall wrap starts from $12 per m2. More premium foam products such as Kingspan Kooltherm start from $26 per m2. Also read: How much does insulation cost per m2?

Handling and installation

Both foam and fibreglass products are easy to handle and suitable for DIY applications. They can be cut easily using a sharp utility knife and are safe to use, although we recommend wearing safety glasses, long sleeves and enclosed shoes for any DIY installation.

Rigid foam insulation is non-toxic, non-itchy and contains no breathable fibres. In the past, fibreglass products have had a notorious reputation for being itchy to work with. However modern products like Knauf Earthwool insulation use special technology to reduce the itch factor to virtually nothing. An advantage of fibreglass batts is that they’re flexible and can be moulded around shapes and awkward gaps if needed.

Longevity

The foam and fibreglass products we sell at Pricewise Insulation are designed to last the lifetime of your house. We recommend checking the specific warranty of a product to compare longevity. Fibreglass products typically have a longer warranty than foam insulation. On average, our fibreglass insulation products come with manufacturer warranties over 50-70 years, while many of our foam products are backed by 10-25 year manufacturer warranties.

Sustainability

Foam insulation and fibreglass insulation will both help make your home more environmentally friendly by reducing heat loss and gain throughout the year. The higher the R-Value you insulate with, the greater the energy efficiency you can achieve. Fibreglass products are often made from over 80% recycled glass materials, and many of the fibreglass products we sell can be recycled. For more information about the sustainability of fibreglass vs foam, we recommend researching the particular companies that produce the products. Many companies have sustainability measures in place to reduce greenhouse gas emissions and cut down on waste. Also read: Environmentally friendly insulation options for Australian homes.

What type of insulation is best for my project?

Foam insulation applications

Foam insulation is best suited to applications such as:

Exterior wall sheathing
Garage doors and floors
Underneath floors, particularly floors with a radiant heating system
Concrete slab insulation
Around trenches and edge beams and in between pods

Our top foam insulation products include:

Fibreglass insulation applications

Fibreglass or glasswool batts are a good option for applications such as:

Exterior and interior wall cavities
Ceilings and attic spaces
Under floors
Between floors of a multi-storey house
Soundproofing rooms

Our top fibreglass insulation products include:

The right insulation for your home

Still not sure what the best insulation is for your project? Ask our friendly team of experts at Pricewise Insulation. We can help you choose the right product to get the best performance and a great return on your investment. Place an order for fibreglass insulation or foam insulation today. Or call us on 1300 729 639 for more information.