If you’ve come across wood fibre insulation, chances are you’ve heard it described as “eco-friendly.” And that’s true. But if that’s where your understanding stops, you’re missing out on what really makes it such a standout material.
This isn’t just about sustainability. It’s about performance. In this article, we’ll look at how wood fibre behaves in a building: how it deals with heat, handles moisture, and makes life easier for the people who install it. Whether you’re just starting out or already working on your own projects, this is a material worth knowing properly.
Check out Episode 17 of the Can I Just Ask? video series where Chris Brookman and Andy Banister talk through this topic.👇
Yes, it’s green—but that’s just the beginning
Let’s start with the obvious. Wood fibre insulation is made from leftover timber—often waste from sawmills or forest management. So instead of going up in smoke or being dumped, that material gets turned into something useful. It also stores carbon, because the CO₂ captured by the tree stays locked inside the insulation for decades. So it’s a low-impact, renewable product with a genuinely positive story.
But that’s not why we use it. At least, not mainly.
Keeps heat out as well as in
What really makes wood fibre insulation interesting is how well it manages heat. Most people think insulation is just about keeping heat in during winter. And yes, wood fibre does that. But it also performs brilliantly in hot weather.
The science behind it comes down to something called specific heat capacity. In plain terms, that’s how much heat a material can absorb before it starts to feel warm. Wood fibre can soak up a lot of heat before its temperature rises, which means it slows down the movement of heat through walls and roofs. That makes buildings feel cooler, for longer, during hot spells.
This is especially useful in homes with lots of glazing or in parts of the country where summer temperatures are creeping up. Passive cooling is becoming just as important as heating performance—and wood fibre delivers on both.
Helps the building breathe
Another big benefit is moisture control. Wood fibre is vapour-permeable, which means it allows water vapour to move through it rather than trapping it. That’s important in any building, but especially in older ones or in retrofits where moisture movement is a real concern.
It also buffers humidity. If the air inside is too moist, the insulation will absorb some of that vapour and release it gradually when things dry out. This helps prevent issues like condensation and mould, and supports better indoor air quality. In short, it’s a smart, responsive material that contributes to a healthier building environment.
Easy to work with, and forgiving on site
There’s also a lot to be said for how it behaves during installation. Wood fibre boards can be cut easily, they don’t itch or off-gas, and in their dense formats, they’re designed to friction-fit snugly between studs or rafters. That means fewer gaps, better air tightness, and a lower chance of thermal bridging—where heat slips through cracks or joints in the insulation layer.
And because it’s breathable and tolerant of small construction errors, it’s a forgiving material. If you’re learning the ropes or working on a tricky retrofit, that flexibility can make a huge difference.
So why do we keep choosing it?
Simple. Because it works. Over the years, we’ve tried all kinds of insulation materials, and wood fibre keeps rising to the top—not just because of its sustainability, but because it performs consistently well across all the metrics that matter: thermal control, moisture management, ease of use, and durability.
It’s natural, yes. But it’s not old-fashioned or basic. It’s technically robust, rigorously tested, and well-suited to the way we build today.
If you’re looking to create buildings that are comfortable, efficient, and built to last, wood fibre insulation deserves a spot in your toolkit.