Cork Underlayment Installation Guide

Quite easy to install, environmentally friendly cork underlayment does not deteriorate after years of use. Natural cork underlayment is recommended for sound reduction and stress crack protection. It has been independently tested according to ASTM standards for acoustical values.

Installation:
Read and understand this data sheet completely before you begin your installation

Surface Preparation:
Surfaces must be clean, dry and smooth, free of voids, projections, loose materials, oil, grease, sealers and all other surface contaminants. Maximum floor variation is 1/8” in 10 feet. Surface areas requiring patching or leveling should be repaired with cement materials.

Creating an Isolation Barrier:
Unroll cork and cut sections approximately 2” wide off roll. Adhere this 2” isolation barrier around perimeter of the entire floor with any of the entire products: Urethane Adhesives, Natural Rubber Latex Adhesives, Cartridge Filled Urethane and Acrylic Bead Mastics. Never mechanically flatten the isolation barrier with screws, nails or staples. This will severely diminish acoustical values of the barrier.

Installing the Sound Control Underlayment:
Unroll cork and cut to desired length. Lay cork loosely over area to be installed. Both ends of the roll must curl down towards the subfloor. If the ends curl up, flip material over. Butt cork directly against the isolation barrier already installed.

Pull the loose laid material back at least half the length of the roll.
Using a 3/16” x 5/32” v-notch trowel, apply any of the Bostik products listed above to the subfloor. Gently return the pulled back material ad roll in both directions with a 100 lb. roller. Repeat this procedure for the other half of the roll. Proceed to cover the entire floor making sure all joints are butted together tightly. Note: If BossTack adhesive is used, allow it to flash until dry, and then apply cork and roll with a 100 lb. roller (refer to BossTack data sheet)
Allow cork adhesive to take a firm set prior to installing hardwood or ceramic tile flooring. Read adhesive manufactures instructions to determine adhesive set time.

Wood Flooring Installation: Apply to cork as follows:
Follow industry standards and wood floor manufacturer recommendations for subfloor moister content, design, layout and application of wood flooring materials.
Refer to Bostik’s Best, BST Urethane, or BossTack adhesive data sheets for full wood flooring installation instructions.
After the wood floor is installed, trim the isolation barrier ¼” below the finished floor surface.

Natural Cork
Underlayment is available in 4’x 50’ x 6mm rolls. Other thicknesses available are 1/8” and 5/64”. Also available in 3’ x 2’ sheets ½” thick and ¼” thick.

Ceramic Tile Flooring Installation: Apply to cork in the following method:

1. Install ceramic tile according to applicable ANS standards using Hydriment Single-Flex; Hydroment PM; or Tile-Mate thin set Mortars mixed with #425 Multi-Purpose Acrylic Latex Admixture or #447 Flex-a-lastic Admixture.
2. Refer to setting mortars data sheets for complete instructions.
3. After the tile floor has been installed, trim the isolation barrier ¼” below the finished floor surface.
4. Caulk the trimmed areas with a bead of acoustical sealant; flush to the finished floor.