When selecting insulation materials, it's wise to consider more than just upfront costs. Budget-friendly options might look appealing, but over time, they often lead to hidden problems and extra repair expenses. Not every product is designed to effectively seal spaces or provide reliable protection. One material that truly stands out is expanded cork granules – naturally resilient, moisture-resistant, dimensionally stable, and completely eco-friendly.
Lightweight & strong
100% Natural Origin
High Insulation Value
Durable & Long-Lasting
Lower Carbon Footprint
Safe for Everyday Use
Curious about the details? Here's what you should know.
WHAT ARE EXPANDED CORK GRANULES?
Expanded cork granules are the result of heating natural cork, which causes the material to expand and darken. This process is entirely natural—no synthetic additives involved. The heat activates suberin, a compound found in cork that acts as a natural binder, holding the granules together effectively.
HOW CAN THEY BE USED?
Thanks to their versatility, cork granules can be applied across various industries and DIY projects:
- Insulating hard-to-reach spaces in attics, walls, floors, and ceilings,
- Filling cavities in wall assemblies, partitions, and floor voids,
- Used between rafters in pitched roofing structures,
- Leveling uneven surfaces prior to flooring,
- Perfect for dry screeds and lightweight flooring systems.
Beyond the construction world, cork granules serve well in:
- Terrariums – safe bedding for reptiles and exotic pets,
- Landscaping – natural mulch alternative to pine bark,
- Film productions – to mimic soil, debris, or rubble for visual effects,
- Scale models – excellent for architectural or hobbyist displays.
WHAT MAKES EXPANDED CORK SPECIAL?
Cork is widely praised for its superior insulation properties—it effectively resists both heat and sound. But there's more:
- Incredibly lightweight without compromising strength,
- Naturally resists mold, mildew, and pests,
- Maintains shape and density over time,
- Free from toxic chemicals or volatile compounds,
- Biodegradable and planet-friendly,
- Stands up to extreme temperatures from –292°F to +248°F,
- Tested fire behavior with Euroclass E rating—doesn't emit toxic fumes.
IS IT SAFE TO USE?
Absolutely. Our expanded cork granules are backed by a certified hygienic rating from the National Institute of Public Health in Poland. They are non-toxic, non-allergenic, and do not cause irritation—making them a safe option for households and construction professionals alike. We are currently the only brand in Poland with this certification.
IS CORK A GREEN MATERIAL?
Yes, and in more ways than one. Cork is harvested from the outer bark of cork oak trees, which naturally regenerates every 9 to 12 years. There's no need to cut the tree down—just remove the bark and allow it to regrow. That makes cork a renewable, sustainable, and tree-friendly resource.
On top of that, cork trees absorb significantly more CO₂ than other trees, giving this material a negative carbon footprint.
HOW LONG DOES IT LAST?
Expanded cork granules are engineered to last. You can count on their insulating performance for up to 50 years, with no significant degradation in quality.
WHAT DOES IT LOOK LIKE?
The granules are a dark brown color—this occurs naturally during the heating process. They are not painted, stained, or chemically treated, giving them a rustic and organic appearance compared to lighter cork products.
WHAT'S THE MATERIAL DENSITY?
The bulk density for the 2–9 mm fraction is approximately 70–80 kg/m³, which equals around 4.4–5.0 lb/ft³.
DO YOU ALSO OFFER CORK SHEETS?
Yes, we do. Expanded cork panels are also available as part of our product range, perfect for flat-surface insulation projects or interior applications.
HOW DOES IT COMPARE TO FOAM INSULATION?
While foam insulation is popular, it tends to deteriorate over time. It can shrink, become brittle, or break down chemically. Cork, on the other hand, maintains integrity over decades and doesn’t rely on synthetic binders or petrochemicals.
- Longer-lasting and more dimensionally stable than foam,
- Non-toxic and free from VOCs,
- Naturally mold and insect resistant,
- Zero harm to the planet—fully biodegradable.
HOW SHOULD IT BE STORED?
Store expanded cork granules in a dry, ventilated area. Avoid damp basements, sealed bags, or outdoor areas exposed to sun or rain. Proper airflow helps prevent any moisture buildup and keeps the material in optimal condition.
In short: keep it dry, cool, and well-aired—no heat sources, no humidity, no direct sunlight.
A lot of people assume that being eco-conscious means sacrificing performance. But let’s face it – your home’s not a lab for trial-and-error. Thankfully, expanded cork isn't a gamble – it's a reliable, time-tested natural material that beats synthetic fillers hands down. You don’t have to choose between sustainability and functionality – this stuff delivers both, effortlessly.
#1 NATURE VS SYNTHETICS – CORK TAKES THE CROWN
If you've ever used bargain-bin synthetic insulation, you already know the headaches: poor longevity, hidden costs, and weak performance. Sure, they’re cheap – but you get what you pay for. Expanded cork flips the script. It’s dependable, consistent, and long-lasting. Install it once and forget about it. No adhesives, no binders, no nonsense – just years of peace of mind.
Not every material is cut out for granular insulation. Some crumble, clump, or collapse under pressure. Expanded cork stays intact – its stable, featherlight structure doesn’t change over time. Because filling a gap is one thing. Making sure it holds up a decade later? That’s real value.
#2 GREEN SHOULDN’T BE A FAD – IT SHOULD BE THE STANDARD
We’re surrounded by single-use plastics, foams, and synthetic junk – most of which ends up in dumps or polluting our natural spaces. What’s worse, their production burns through energy and adds to carbon emissions. And what do we get in return? Short-lived products that stick around in landfills for centuries. Expanded cork flips the narrative – it’s clean, earth-friendly, and naturally biodegradable.
Here's the kicker: cork oak trees grow back without being chopped down. They naturally regenerate their bark, offering a sustainable source for insulation. Yet we still lean on polluting synthetics. Why? Because they’re “cheap”? The planet pays the price. Natural cork changes the game – no toxic waste, plus it helps capture CO₂ from the atmosphere. A win for your home and the environment.
#3 CORK – MOTHER NATURE’S VERSION OF POPCORN
Think of popcorn: heat a kernel and it puffs into something light and airy. Cork acts the same way when exposed to high temps (minus the butter and microwave).
It all starts with the cork oak's bark, gently harvested by hand without harming the tree. When heated, the cork cells expand – puffing up and turning dark. This natural process releases suberin, a plant-based binder that holds everything together like glue, but without chemicals.
The result? Expanded cork boasts insulation properties that leave raw cork in the dust. It’s more porous, traps heat better, and blocks out noise more effectively. Basically, it’s cork – but upgraded.
#4 LIGHTWEIGHT, MULTI-PURPOSE & NON-TOXIC
Expanded cork granules are light as air – easy to carry, pour, and fit into tight spaces where rigid insulation doesn’t cut it. No back strain, no heavy lifting.
Unlike many synthetic options that can off-gas or irritate your skin and lungs, expanded cork is totally safe. No VOCs, no allergens, no harsh chemicals – just a clean, breathable solution for any home.
| Fraction | 2-9 mm |
| Volume | 250 l (0,25 m³) - 18 kg |
| Color | Dark brown |
| Material | Expanded cork |
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