6mm Cork Underlayment Overview
Forna 6mm cork underlayment provides thermal insulation and sound control. Check compatibility with the finished floor and the required acoustic assembly.
Each sheet measures 2ft x 3ft (24” x 36”). A carton contains 25 sheets and covers approximately 150 square feet. See packing details for shipping weight.
Made from 100% agglomerated cork with water-based binders. Review the emissions and sourcing documentation for this Portugal-made product.
Performance & Benefits
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Acoustic Insulation: Effectively reduces both airborne and impact noise thanks to cork’s unique cellular structure (40 million cells per cubic cm).
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Elastic Support: Provides natural cushioning and resilience, protecting the surface floor and improving walking comfort.
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Moisture Resistance: Suberin, cork’s natural wax, offers resistance to mold, mildew, and microbial growth, adding protection to flooring systems.
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Thermal Barrier: Prevents cold transfer from the subfloor and retains room temperature, improving energy efficiency and enhancing underfloor heating performance.
This versatile underlayment is suitable beneath hardwood, engineered wood, bamboo, cork flooring, laminate, and tile. It not only supports your flooring structurally but also improves indoor comfort, well-being, and energy savings.
A Truly Sustainable Choice
Cork is harvested from cork oak bark. Published product background describes a tree lifespan of up to 200 years and around 15 harvests. Review the complete underlayment’s construction and project requirements.
Key Product Details
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Material: 100% Agglomerated Cork
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Thickness: 6mm (¼”)
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Sheet Size: 24” x 36” (2ft x 3ft)
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Density: 220kg/m³ ±10%
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Coverage: 150 sq. ft. per carton (25 sheets)
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See packing details for shipping weight.
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Origin: Portugal
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Certifications: MSDS, Resin Statement
Acoustical Ratings (Field Tested):
- IIC 50 (on 6” concrete without suspended ceiling)
- IIC 64 (on 6” concrete with suspended ceiling)
- STC 51 (on 6” concrete without suspended ceiling)
- STC 65 (on 6” concrete with suspended ceiling)

Info & Guides
HOA approval? Download the HOA Flooring Approval Kit — per-thickness test statements, assembly ratings, certificates, and a cover-letter template your board can file.














Chelsea Zhang –
Very nice material that easily cuts with a utility knife. Comes in sheets are easy to lay. You will need a vapor barrier in install in a basement. We got this because our base floors are concrete, we wanted laminate flooring and my wife wanted something a little softer and warm to walk on. This provided all we needed. It has nice cork smell when I opened box.
Andrew KRIENING –
Flooring to an up stairs floor where the sound was quite loud before application of this cork underlayment. Once it was layered I added 1/2 “ cork floating flooring which really made a difference of the noisy sound.