Installation Guide

Whisper Step® Plus
Installation Instructions
Whisper Step® Plus is the most versatile acoustical underlayment available today. Not only does it help reduce in-room and
between-story noise but also acts as a breathable moisture barrier. Whisper Step® Plus is guaranteed to perform over the life
of the floor. It offers different installation methods making any project worry free.
Always consult with the flooring and adhesive manufacturers for their product conditioning and installation requirements. Vinyl Composition
Tile is specifically excluded.
Suitable Substrates -- Concrete Slab and Wood Subfloor
1. Floor must be clean, dry, flat, and structurally sound.
2. Always test for moisture before installing flooring. For concrete, test using the anhydrous calcium chloride test (ASTM
F2170) and for wood, use either an invasive or non-invasive pin probe. If the wood subfloor indicates moisture, check for
proper vapor barrier and venting below the subfloor and correct. Do not add a vapor barrier on top of a wood subfloor.
Note: Whisper Step® Plus has a Water Vapor Emission rate of 0.511 lbs. per 1,000 square feet per 24 hours and a Permeance of 2.329.
Installing Whisper Step® Plus to Substrate
Floating Method
Luxury Vinyl Tile (incl. attached back), Engineered Wood, Laminate, Carpet Tiles, Sheet Vinyl (perimeter glued/fastened)
1. Floated—may be loose-laid.
2. Cut material to fit the room leaving 1/8” gap around perimeter of the room.
3. Run underlayment perpendicular to plank flooring or at a 45-degree angle for square tile flooring.
4. Join seams by butting material and seam joints with clear 2” packing tape.
Glue Down
Luxury Vinyl Tile, Engineered Wood, Laminate, Carpet Tiles, Ceramic/Porcelain Tile, Sheet Vinyl (felt backed)
1. Adhesive bond – Use a premium pressure-sensitive or multipurpose adhesive.
2. Run underlayment perpendicular to plank flooring or at a 45-degree angle for square tile flooring.
3. Use the roll core which came with the Whisper Step Plus® roll to press the underlayment evenly into the adhesive.
4. Join seams by butting material.
Ceramic & Porcelain Tile
1. Thin-set bond– may be used where ceramic tile will be installed.
2. Use a 1/8” x 1/8” square notched trowel if not specified by thin-set instructions.
3. Run underlayment perpendicular to plank flooring or at a 45-degree angle for square tile flooring.
4. Use the roll core which came in the roll to press the underlayment evenly into the thin-set.
5. Allow proper set time before moving to the next step.
Check with thin-set manufacturer to determine if modified or unmodified thin-set is required.
Subfloor must meet local code requirements and deflection load requirements for the specific job; refer to the TCNA handbook for other
requirements and limitations.
Install Flooring over Whisper Step® Plus
Floating Method
Luxury Vinyl Tile (incl. attached pad), Engineered Wood & Laminate – follow manufacturer’s installation instructions.
Glue Down
Luxury Vinyl Tile (incl. attached pad), Engineered & Solid Hardwood, Carpet Tiles, Sheet Vinyl (felt backed): Adhesive bond – For
LVT, use a premium pressure-sensitive adhesive. For other flooring, refer to installation instructions for adhesive requirements.
Sheet Vinyl: Perimeter glued (fastened method) – refer to the sheet vinyl installation instructions.
Ceramic & Porcelain Tile: Thin-set bond – may be used where ceramic tile will be installed. Use a 1/8” x 1/8” square notched
trowel if not specified by thin-set instructions. Allow proper set time before moving to the next step.
Check with thin-set manufacturer to determine if modified or unmodified thin-set is required. Subfloor must meet local code requirements
and deflection load requirements for the specific job; refer to the TCNA handbook for requirements and limitations.
Nail Down
Engineered & Solid Hardwood: Nail-down – Suitable in nail/staple down applications. Refer to the flooring installation
instructions.
During noticeable changes to temperature and humidity, pay especially close attention to the adhesive recommendations and adjustments
which may be required. Underlayment may not prevent the flooring from contracting or expanding because of temperature and humidity
changes. Consult with the flooring manufacturer for questions regarding the installation, care, and maintenance of your new floor.