SPECIFICATION GENERATOR
Find out which low impact materials are right for your building project.
Why Do We Use Wood Fibre Insulation? – Can I Just Ask? | Ep.17
Wood fibre insulation has become a staple in sustainable construction – but not just because it’s a low-carbon material. At Back to Earth, we specify wood fibre time and again not for its popularity or its environmental story (though those help), but because it’s one of the most technically capable, reliable, and pragmatic insulation materials available. Here’s why.
Check out why we think this, in this weeks episode of Can I Just Ask? Chris and Andy from our technical team go through this question. Watch Now!👇
More Than Just a Green Choice
It’s easy to assume that wood fibre insulation earns its place in our specifications purely for environmental reasons. After all, it’s made from waste timber, stores carbon, and avoids the petrochemical footprint of conventional insulants. These are compelling credentials in the context of climate-conscious construction.
But increasingly, the environmental angle is just the starting point. What truly sets wood fibre apart is its ability to meet a demanding set of performance criteria – thermal, moisture, and acoustic – consistently and effectively.
Thermal Performance Where It Counts
One of wood fibre’s standout features is its high specific heat capacity, which gives the material substantial thermal mass. This makes it extremely effective at slowing the transfer of heat, especially important in the context of summer overheating, which is fast becoming one of the most pressing design challenges in both new-build and retrofit.
Unlike lightweight insulants that might meet the same U-value on paper, dense wood fibre boards can delay heat ingress significantly, increasing the building’s thermal phase shift. This helps keep internal spaces cooler during hot spells, reducing reliance on active cooling systems and improving occupant comfort.
Airtight, Gap-Free, Reliable
In real-world construction, achieving designed performance targets often hinges on installation quality. Here, wood fibre shines again. Its density and friction-fit capability make it easier to install without gaps or voids, reducing thermal bridging and air leakage.
That’s especially true with dense pack or rigid board formats, where friction-fitting into stud bays or across rafters gives a snug fit that holds its shape over time. For designers and contractors looking to close the performance gap, this reliability is a major win.
Hygrothermal Performance and Breathability
Wood fibre isn’t just thermally robust, it’s also one of the best performers in terms of moisture buffering and vapour permeability. It allows vapour to pass through the structure safely, reducing the risk of condensation build-up, mould, or long-term material degradation.
This breathable characteristic makes wood fibre an ideal match for natural plasters and other vapour-open materials, enabling holistic, healthy building assemblies that regulate internal humidity and support fabric durability.
Installer- and Occupant-Friendly
From a health perspective, wood fibre is also a safe, low-toxicity product. It’s pleasant to handle, without the skin irritation, off-gassing, or hazardous fibres associated with many synthetic alternatives. That’s better for the people installing it and for those living with it long term.
Its inherent practicality – from ease of cutting to robustness on site – adds to its appeal. For contractors, it’s a material that performs well not just in theory, but in the everyday realities of construction.
The Pragmatic Specifier’s Choice
At Back to Earth, we write specifications to solve real-world challenges. We’re not tied to any one manufacturer, and we don’t choose materials because they’re trendy. Wood fibre consistently makes the cut because it works – technically, practically, and environmentally.
In an industry rightly focused on reducing carbon, it’s worth remembering that not all “green” products are high-performance – and not all high-performance products are green. Wood fibre, rare among insulants, ticks both boxes. That’s what makes it a standout material in modern, sustainable construction.