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ThermaCork 4" Standard Grade Cork Insulation

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TC 100-3
0.00 LBS
  • Product Description








    4" thick panel of cork insulation; 3 boards/pack, 16.5 ft2/pack; dimensions: 4" x 39" x 19 5/8"

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    Insulation cork is a 100% natural, renewable, recyclable, and biodegradable product made from the outer bark of an oak tree, a species called Quercus suber. Cork trees grow primarily in the cork forests of the western Mediterranean. One of the most versatile materials on Earth, the use of cork as a building product is growing substantially. 


    The harvesting and production of insulation cork is not only sustainable, but it also serves to provide employment and economic purpose for many communities. Cork harvesting is an ancient tradition, thousands of years old. Nowadays, it's done by hand for two months a year - June and July - when a skilled cork harvester splits off the bark of a cork oak tree without damaging the rest of the tree. In fact, the trees flourish from this process. EAch tree can live between 150 and 250 years, and is harvested every nine years. After harvesting, the removed bark is dried in the sun, and handled differently depending on its use. Expanded Insulation Cork Board is produced from the natural cork granules which are steam-heated, causing the cork to expand. This activates suberin, a natural binder, requiring no added binders or chemicals during the production of insulation cork. Throughout this process, nothing is wasted. All waste is returned to the production process, making cork harvest and production one of the most sustainable business practices on the planet.


    • Cork is high on the insulating range at R-4 per inch depending density, meaning reduced heating costs
    • Dimensionally stable, with no appreciable shrinkage over time
    • Cork is incredibly stable and can cope with major thermal variations, between (-) 292 degrees F to (+) 248 degrees F. Thermal resistance does not decrease over time like man-made foam
    • Reduced mold risk in sheathing due to cork's permeability, allowing water to "dry through" layers, preventing mold and rot
    • More resistant than other rigid insulations to compression, creating a flat plain for a smooth wall
    • Excellent sound isolation
    • When applied to an exterior layer, cork drastically reduces thermal bridging at the wall and rim joist
    • Hypoallergenic and free of all domestic toxins. In the case of fire, it releases no toxic gases
    • Does not shrink or "off gas" like EPS, XPS, or Polyiso foam boards
    • Recyclable and reusable after deconstruction
    • Unlimited durability, maintaining its technical characteristics


    • Thermal Conductivity: 0.036-0.038 W/mk for a declared value of EU label of 0.04 W/mk
    • Thermal Resistance: R-4/inch
    • Density: 7.0-7.5 lbs/ft3
    • Perpendicular Face Resistance: 60 Kpa or 8.7 PSI
    • Compression Resistance: 10% at 100u Kpa or 14.5 PSI
    • Permeability:
      • 1 1/2" thickness: 2.15 US perms
      • 2" thickness: 2.04 US perms
      • 4" thickness: 1.26 US perms
    • Maximum Moisture Content: 8% with water absorption declared at 0.5 kg/m2
    • Longitude Tolerance: +/-0.1 to 0.2" or +/-3 to 5 mm
    • Thickness Tolerance: 0.04 to 0.1" or +/-1 to 2 mm
    • Fire Resistance: Euro Class "E"


    Thermal conductivity tested by the independent laboratories: CSTB (France) and LNEC (Portugal). Industrial quality/Quality control by CSTB (twice annually). Other certifications: MPA Stuttgart-Otto-Graf-institut (quality verification). ARGEKDR – Zertifikat no. –R0700144 “R” green vegetal. ACERMI by CSTB.

    Please call us at 1-855-FOR SIGA (855-367-7442) for a delivery estimate or visit

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