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When you're selecting insulation, it’s smart to think long-term. Bargain options can seem like a win at first, but they often turn into a costly mistake down the road. Plus, not all insulation fits snugly or is entirely safe. But there are materials that break the mould – like expanded cork granulate. Long-lasting, resists damp, holds up well, and comes straight from nature.
Durable Yet Lightweight
Natural
Top Insulation Qualities
Durable
Eco-Conscious Material
User-Friendly and Safe
Wondering about something? We’ve already got the answers!
WHAT IS EXPANDED CORK GRANULATE ?
Small pieces of expanded cork – this lightweight, nature-made material actually performs better than regular cork in insulation.
Expanded cork is produced by heating cork oak bark until it expands and turns a rich brown. No artificial additives are used – the method is entirely natural. It contains suberin, a plant-based resin that acts as a glue when heated, holding the cork together organically.
HOW IS EXPANDED CORK GRANULATE TYPICALLY USED?
It's used most often in building work, including:
- insulating lofts, floors, ceilings, and walls – especially tricky or tight spaces,
- filling gaps in cavity walls, hollow walls, and thermal insulation partition systems,
- roof insulation – poured between rafters in pitched roofs,
- underneath floors or inside structural voids,
- level-adjusting uneven floor or ceiling sections,
- dry screed applications,
- creating lightweight base layers for floors.
But it's not just for building – other uses include:
- terrariums – a safe, natural bedding for exotic animals and reptiles,
- gardening – as a mulch or decorative layer under plants, instead of pine bark,
- film work – simulating soil, rocks or debris for action scenes,
- model construction – ideal for miniature builds and creative dioramas.
WHY IS EXPANDED CORK SUCH A GREAT MATERIAL?
Mainly because of its excellent insulating ability – it blocks heat and noise better than traditional natural cork.
Other useful traits include:
- Lightweight – won’t strain building structures,
- Naturally defends against mould, pests, and fungi,
- Inert – doesn’t react with chemicals,
- Keeps its shape long-term,
- Long-lasting and reliable,
- Naturally biodegradable and environmentally friendly,
- Can tolerate extreme cold and heat – from –180°C to +120°C without damage,
- Fire-safe with Euroclass E rating – no harmful gases when exposed to flames.
ARE CORK GRANULES RISK-FREE TO USE?
Yes, these cork granules are certified with a Polish hygienic approval from the National Institute of Public Health. They’ve been verified as non-allergenic, non-irritant, and safe to use. We're proud to be the only company in Poland currently holding this certificate.
IS NATURAL CORK A TRULY ECO MATERIAL?
Yes indeed – cork is one of the greenest materials available. It's harvested from the bark of cork oaks, so there’s no need to cut down any trees. The bark regrows naturally every 9 to 12 years, making it a renewable resource that doesn't harm the tree or the environment. These trees can live for centuries – even over 200 years!
Even better, cork is known for its carbon-negative impact. In fact, cork oaks can absorb up to four times more CO₂ than other tree species.
HOW LONG DO CORK GRANULES KEEP THEIR QUALITIES?
Expanded cork granules are built to last – their performance can remain effective for up to 50 years.
WHAT’S THE COLOUR OF EXPANDED CORK?
It has a rich dark brown look, created through high-heat treatment. There’s no added colouring or paint involved.
WHAT IS THE DENSITY PER CUBIC METRE?
For grain sizes ranging between 2 and 9 mm, the density falls around 70–80 kilograms per cubic metre.
DO YOU PROVIDE CORK IN SHEETS?
Yes, we also have expanded cork available in sheet form.
HOW DOES CORK STACK UP AGAINST FOAM INSULATION?
Overall, cork comes out on top. Foam is synthetic and tends to break down with time – it can shift, crack, or lose its insulating seal. Plus, producing foam has a pretty large environmental impact.
Meanwhile, cork:
- Has much better long-term durability,
- Is completely natural and harmless – safe for health and the planet,
- Resists mould, pests, and fungal growth,
- Is biodegradable and contributes positively to CO₂ absorption.
WHAT’S THE BEST WAY TO STORE EXPANDED CORK GRANULATE?
Store them in a place that’s dry and has good air circulation. Don’t leave them in damp basements or under plastic sheeting outside. Keep them away from heaters and direct sunlight too.
To keep it simple: they should stay dry, well-ventilated, and away from any heat sources or sun exposure.
We sometimes assume that choosing eco options means compromising on quality. And let’s be real – no one wants to test that theory at home. But expanded cork isn’t some wild experiment – it’s a solid, well-proven material that actually performs better than many synthetic alternatives. It gives you both sustainability and efficiency – no need to sacrifice one for the other.
#1 NATURAL CORK VS SYNTHETICS – NO CONTEST
Anyone who’s dealt with budget synthetic insulation knows it doesn’t take long before the problems begin. It might seem like a bargain at first – but later on, it often leads to headaches. Expanded cork tells a completely different story. You apply it once, and it keeps delivering – no top-ups, no fixing, just long-term reliability without the need for chemical enhancers.
Some materials just don’t hold up when turned into granules – they clump, break down, or lose shape. Expanded cork doesn’t do that. It stays loose, stable, and lightweight. Because insulating properly isn’t about a quick fix – it’s about trusting that what’s inside your walls will hold up year after year.
#2 BEING GREEN IS JUST BEING SMART
Modern life is filled with plastics, foams and synthetic materials that, after a short life, become waste – sometimes dumped in nature, sometimes burned. Their production also drains resources and emits loads of carbon. The outcome? Short-lived materials that leave a lasting impact. Expanded cork doesn’t add to the problem – it’s a solution that’s kind to the planet and fits right in with natural systems.
Here’s the irony: cork is a renewable material – it regenerates without the need to cut down trees – and still, we fall back on man-made options. While they might seem budget-friendly, their hidden environmental toll is high. Cork changes the equation. It leaves no trace behind, and cork oaks help the Earth by absorbing large volumes of CO₂, actively reducing emissions.
#3 POPCORN? CORK WORKS IN A SIMILAR WAY
Just like popcorn kernels puff up under heat, cork goes through a similar expansion process. It all begins with the outer bark of cork oak trees. It’s hand-harvested gently, keeping the tree intact, and then heated at high temperatures. At that stage, the cork cells expand – becoming larger and more porous. The heat also darkens the cork and activates suberin – a natural plant resin that binds everything together.
This natural transformation gives expanded cork much better insulation power than raw cork. It becomes more breathable, holds warmth longer, and blocks out sound more effectively.
#4 EASY TO HANDLE, SAFE TO USE
Expanded cork granules are super light – you can carry and pour them without any hassle. They’re especially handy in spots where traditional insulation boards just won’t work.
And here’s a big plus: expanded cork is completely non-toxic. It won’t irritate your skin, it’s allergy-friendly, and it doesn’t release harmful chemicals or fumes. It’s clean, simple and safe to use anywhere.
| Fraction | 2-9 mm |
| Volume | 2000 l (2 m³) - 140 kg |
| Colour | Dark brown |
| Material | Expanded cork |
