Premium Quality Cork Underlayment

Our premium cork underlayment is for commercial and residential applications. Cork sheet and cork roll underlayment is a natural choice for sound control.   Cork Direct underlayment is an effective, economical means to provide an acoustic barrier for flooring materials. Cork underlayment is environmentally sound and quick and easy to install. Even after years of use, our premium quality cork underlayment will not deteriorate.

Cork Direct’s cork underlayment is recommended for sound reduction and stress crack protection. It has been independently tested using ASTM standards for acoustic values. All Cork Direct brand cork underlayment is made entirely of premium quality European cork.

All Cork Direct underlayment, up to container quantities,is available for time critical jobsite delivery.

Cork Direct brand cork underlayments with densities of 11.7 lb/ft3 – 12.5 lb/ft3 provide significant acoustic insulation.  See technical information below.


Cork Direct Underlayment Technical Specifications

Description: Composition cork underlayment for commercial and residential applications.
Sizes: Available in sheets and rolls of various sizes and thicknesses.
Binder: Resin of Polyurethane
Base: Composition cork granules sizes 1 – 3
Density: 11.7 lb/ft3 – 12.5 lb/ft3
Tensile Strength: 5 – 8 Kgs/cm2
Recovery: 75%
Flexibility F5: Pass
Disintegration: None after 3 hours immersion in boiling water.
Thermal Insulation: 0.042 Kcal/m3 h0 C


Acoustical Ratings: (1/4″ – 6mm cork underlayment)

Ceramic Finish Ceramic Finish Wood Finish Wood Finish
Concrete Slab 8″ 58 60 56 62
Concrete Slab 6″ 53 58 54 59
Concrete Slab 4″ & Steel Deck 60 64 60 65
Wood Joist Construction 54 59 54


Fire Behavior:
The underlayment is a fire inhibitor which neither spreads flame nor releases toxic gases on combustion
Dimensional Tolerance:Length & Width: +/- 0.5mm  Thickness: +/- 0.2mm



Cork Direct Underlayment Installation Instructions

Getting Help
Please read these instructions before beginning an installation. If you have any questions, or if you feel you need more information, please call technical support at (800) 344-CORK, or email:techinfo@corkdirect.com.

Surface Preparation.
Surfaces must be clean, dry and smooth, free of voids, projections, loose materials, oil, grease, sealers and other contaminants. Surface areas which require patching or leveling should be repaired with Portland based cement materials.

Maximum floor variation is 1/8” in 10 feet.

Creating an Isolation Barrier
Unroll the cork underlayment and cut sections approximately 2” wide from the roll. Adhere the 2” sections around perimeter of the entire floor with Cork Direct Fortane Urethane underlayment adhesive, to form an effective isolation barrier.  Never mechanically fasten the isolation barrier with screws, nails or staples. Fasteners of any kind will transmit sound and severely diminish the acoustical values of the barrier.

Installing Underlayment in Rolls
Unroll the cork underlayment and cut it to the desired length. Lay it loosely over area to be installed, with both ends of the roll curling down towards the subfloor. If the end curls up, flip material over. Abut the cork directly against the isolation barrier already installed.

Pull the loosely laid material back at least half the length of the roll. Using a 3/3 2” x  3/3 2” x 3/3 2” v-notch trowel, apply Natural Cork Underlayment Adhesive at a spread rate of 100 square feet per gallon. Gently return the pulled back material and roll in both directions with a 100 lb. roller.

Repeat this procedure for the other half of the roll. Cover the entire floor making sure all joints are butted together tightly. Allow the cork adhesive to take set firmly before installing hardwood or ceramic tile.

Installing Cork Direct Underlayment Sheets

Follow instructions as above, but without concern for curl, as the sheets will lay flat.

Wood Flooring Installation

  1. Follow industry standards and the wood floor manufacturer’s recommendations for subfloor moisture content, design, layout and application of wood flooring materials.
  2. Before the wood floor is installed, trim the isolation barrier 1/4” below the finished floor surface.
  3. Install the wood floor with a recommended  adhesive over the Cork Direct underlayment.

Ceramic Tile Flooring Installation

Install ceramic tile according to applicable ANSI standards and manufacturers’ instructions using Hydroment Single-Flex, Hydroment PM, or Tile-Mate Thin-Set Mortars mixed with #425 Multi-Purpose Acrylic Latex Admixture or #447 Flex-a-lastic Admixture.

  1. Before the tile floor is installed, trim the isolation barrier 1/4” below the finished floor surface.
  2. Caulk the trimmed areas with a bead of acoustical sealant, flush to the finished floor.
  3. Install the tile floor.

Carpet or Laminate Flooring installation

Lay cork underlayment loosely over the area to be installed. Before installing carpet or laminate flooring, trim the isolation barrier 1/4” below the finished floor surface.  

Cork Underlayment Warranty

Cork Direct warrants its products to be free of any and all manufacturing defects. No other warranty is expressed or implied.

Want More Information?

Questions, additional data or installation information email us at:info@corkdirect.com .  Or call us toll free at 1-800-344-2675 (CORK)