Every batt of insulation carries a number on its packaging. That number is measured under ideal conditions, in a laboratory, at full thickness.
The cavity in a real house is less forgiving. Insulation is compressed into packaging, carted across the country, dragged through a manhole, and pushed into a space between studs by someone working at height on a hot afternoon.
What matters is not the number on the bag. It is the thickness the product reaches once it is in the wall.
That gap between rated performance and installed performance is one of the least discussed problems in Australian construction. It is also the problem we set out to solve when we designed SupaCell.
This article explains why compression recovery matters, how we engineered for it, and the testing work now underway to prove it.
Compression Is the Quiet Enemy of Thermal Performance
Bulk insulation works by trapping still air. The fibre itself does relatively little. The pockets of air held within its structure are what slow the movement of heat.
Squash the fibre and those pockets disappear. The material becomes denser, thinner, and less able to do the one job it was installed for.
The Australian Government’s YourHome guidance is direct about this, listing compression of bulk insulation among the factors that reduce the total R value of a building element. Its installation advice is blunter still: do not compress bulk insulation, and make sure there is enough space for it to retain its normal thickness.
Gaps compound the problem. Even a small gap can significantly reduce insulating value, which is why a batt that holds its shape and fills the cavity edge to edge is doing more than one job at once.
Insight: Installing roof and ceiling insulation can save up to 45 percent, or more, on heating and cooling costs, while wall insulation typically saves around 15 percent (YourHome). Those savings assume the product performs at its rated thickness. Anything less is money left in the cavity.
What Happens Between the Factory and the Cavity
Compression is not an installation error. It is built into how insulation reaches site.
Batts are compressed for packaging so they can be transported and stored efficiently. That is sensible logistics, and every manufacturer does it. The question is what happens next.
So does compression during transport actually matter, if the product is eventually unpacked? It matters entirely, because a product that never returns to full thickness and retains its shape never delivers full performance.
Some materials recover well. Others stay partly flattened, sit loose in the cavity, or settle over time. The homeowner sees a completed wall. What they do not see is a building envelope quietly underperforming from the day the linings went up.
This is why loft recovery became a design requirement for us rather than a happy accident of the manufacturing process.
Designing a Fibre Structure That Springs Back
Recovery is a material science problem before it is a product feature. It depends on how the fibres are conditioned, how they are blended, and how they are bonded together.
Our nonwoven manufacturing line blends cellulose fibres and processed soft plastics into a consistent mat, with ovens running at around 160 degrees Celsius. That is enough to activate the binder and lock the structure in place, while leaving the cellulose bonded rather than degraded.
The resilience of that structure is what allows the batt to open back out. A bonded fibre network has memory. A poorly formed one does not.
Getting there took repeated trials on feedstock conditioning, blend ratios, and density targets, all measured against how the finished batt behaved once it was unpacked.
For a closer look at the technology behind that process, read here: Inside the Machine: How Nonwoven Technology Turned Kerbside Waste into SupaCell Insulation
SupaCell was engineered so that it:
- Recovers to full loft after being compressed for packaging and transport
- Holds its shape in the cavity, reducing sagging, slumping, and gap formation
- Fits snugly against framing, supporting continuous coverage without forced compression
- Can be fixed in place, including screwed into, for difficult cavity conditions
Testing the Claim Rather Than Repeating It
A design intention is not evidence. Builders, certifiers, and homeowners are entitled to ask what the data actually shows.
That is why we are working with the University of Newcastle through TRaCE, the Trailblazer for Recycling and Clean Energy, to independently examine SupaCell’s compression recovery behaviour and benchmark it against insulation products already on the Australian and imported market.
TRaCE is an Australian Government funded program delivered by the University of Newcastle and UNSW Sydney, established to move recycling and clean energy technologies out of the laboratory and into manufacturing. Its focus on commercialising circular economy research makes it a natural home for a product built entirely from recovered kerbside material.
The research is led by Associate Professor Thomas Fiedler of the University’s School of Engineering. His field is cellular and porous materials, thermal conductivity, and mechanical and thermal material testing. In 2025 he co-authored a study on hemp based insulation that measured exactly this relationship, finding that greater compression produced both higher bulk density and higher thermal conductivity in loose fibre mixtures (Fiedler and Pedersen, Materials, 2025).
That expertise matters here. Compression recovery is not a marketing question. It is a materials engineering question, and it belongs with people who measure this behaviour for a living.
The study examines how SupaCell responds to compression, how completely it recovers, and how that recovery compares with conventional products tested under the same conditions.
This approach is consistent with how SupaCell has been developed from the beginning. Every performance claim has been put through testing, including third party testing against AS/NZS 4859.1 for thermal performance, the standard covering materials for the thermal insulation of buildings.
For the full story of how that four year development journey began, read here: Building the Future, One Fibre at a Time: The SupaCell Story of Australian Innovation
Performance That Has to Last Decades
Insulation is installed once and then forgotten. Nobody lifts the plasterboard in year fifteen to check whether the batts are still doing their job.
That makes long term stability as important as day one performance. YourHome advises checking that loose fill insulation does not settle more than a few percent of its thickness over time, and suggests asking contractors for a guaranteed settled R value. The underlying concern applies to every bulk product: performance measured at installation means little if the material slumps afterwards.
A batt that recovers fully and then holds its position addresses both ends of that timeline. It reaches its designed thickness at installation, and it stays there.
The benefits accumulate quietly:
- Consistent thermal performance across the life of the building
- Fewer gaps and voids, which also supports fire and acoustic performance
- Lower heating and cooling demand, year after year
- Compliance you can rely on, given insulation requirements flow through the National Construction Code administered by the Australian Building Codes Board
Proof Beats Promise
Recycled content is often assumed to mean compromise. We have never accepted that framing, and compression recovery is one of the clearest places to test it.
A batt made from kerbside paper, cardboard, and soft plastics should not have to apologise for its origins. It should be able to stand next to conventional products, under the same test conditions, and be judged on the results.
That is what the TRaCE research is for. Not marketing language, but measured behaviour, compared honestly against the alternatives.
For a closer look at how this collaborative model was built, read here: Engineering the Circular Economy: How Regional Collaboration Redefined Manufacturing
Because insulation is only as good as the thickness it reaches in the wall.
And the thickness it holds for the next thirty years.
Have questions about this article, or anything else about SupaCell? We would love to hear from you. Get in touch with our team today.