6mm Cork Underlayment Overview
Forna’s 6mm cork underlayment provides both comfort and performance by reflecting natural body heat, keeping floors pleasantly warm underfoot. As a mid-range option in thickness, this product strikes the perfect balance between thermal insulation and sound control.
Each sheet is supplied in its natural cork form, pre-cut to 2ft x 3ft (24” x 36”), and conveniently packaged 25 sheets per carton. One box covers approximately 150 square feet and weighs about 44 lbs.
Crafted from 100% agglomerated cork, it is free of toxins and formaldehyde. Even the binders used are water-based, ensuring a healthier, eco-conscious product. From responsible bark harvesting in Portugal to final production, every step is designed to minimize environmental impact while delivering long-lasting quality.
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 a renewable material harvested without harming the cork oak tree. Each tree can live up to 200 years and provide around 15 harvests in its lifetime. Using cork supports healthy forests while delivering a greener, smarter alternative to synthetic underlayments.
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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Weight: 44 lbs per carton
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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.