Expanded granulated cork for thermal and acoustic insulation 3-15mm - 1000l (1 m3) - 70kg

We offer four fractions: 2–4 mm, 2–9 mm, 4–8 mm, and 3–15 mm.

It's expanded cork broken into pieces – this natural, airy material offers even greater insulation performance than the classic cork.

Expanded cork comes from cork oak bark and gets its form through high-heat treatment. This heat makes natural cork expand and turn dark brown – all without using any chemicals. Cork contains suberin, a natural glue-like substance that’s released during the heating stage and helps everything stick together naturally.

It's primarily used in building and insulation work, such as:

• insulating lofts, walls, floors, or ceilings – ideal for spots that are hard to reach,
• filling voids in cavity walls, hollow spaces, and partition walls,
• pitched roof areas – poured loosely between rafters,
• underfloor gaps and empty cavities,
• levelling uneven sections of ceilings and floors,
• used in dry screed systems,
• creating lightweight flooring structures.

Outside of construction, they’re also handy for things like:

• terrariums – providing a clean, natural bedding for reptiles and similar pets,
• garden use – a sustainable alternative to bark under shrubs or as a ground cover,
• film and TV – to replicate dirt, rubble or debris in action scenes,
• modelling projects – great for tiny buildings and realistic dioramas.

The biggest advantage is its brilliant insulation qualities – it blocks heat and noise even better than standard cork.

It also has loads of other perks:

• Very light – easy on structural loads,
• Naturally fights off mould, bugs, and fungi,
• Won’t react chemically with other materials,
• Holds its shape – stays solid over time,
• Durable – keeps working well for decades,
• Biodegradable and all-natural,
• Handles temps from –180°C to +120°C,
• Fire rating of Euroclass E – and no harmful smoke if it burns.

Yes, they’re backed by a Polish health certificate from the National Institute of Public Health, proving they’re safe to use – non-allergenic, non-irritating, and without any side effects. We're currently the only certified provider in Poland to offer this assurance.

Yes, it is – cork is one of the most eco-friendly materials around. It’s taken from the bark of cork oaks, and there's no need to chop the tree down. The bark grows back every 9 to 12 years, so it can be collected multiple times with no harm done to the tree or surrounding nature. Cork oaks live long lives – some even reach 200 years or more.

On top of that, cork has a carbon-negative footprint. These trees can absorb as much as four times the CO₂ that other trees do!

Expanded cork granules deliver insulation that can last for as long as 50 years.

It has a dark brown tone, which comes from the high-temperature heating process. There’s no dye or colouring used. Compared to the usual beige cork, the expanded version looks a bit more raw.

For granules between 2–9 mm, the density usually falls in the range of 70–80 kg/m³.

Yes, we do offer expanded cork in panel form as well.

Cork definitely outperforms foam. Foam is man-made and breaks down over time – it can shrink, crack, or lose insulation properties. Also, making foam creates a large carbon footprint.

By contrast, cork:

• Keeps its shape and function much longer,
• Is eco-safe, non-toxic, and totally natural – safe for people, pets and the planet,
• Naturally resists mould, bugs, and mildew,
• Is fully biodegradable.

It’s best to store it in a dry and well-aired area. Don’t put them in damp basements or under outdoor covers. Also, steer clear of placing them near heat or in direct sunlight.

In short: keep them dry, ventilated, and out of the sun, and away from heaters.