Underlayment is used in flooring to provide a smooth surface for the top floor materials. The flooring underlayment is installed over the subfloor and plays many vital roles when installed properly. The type and quality of the underlay can have an impact on how long the top flooring materials will last.
What types of underlayment are there?
The different types of underlay are appropriate for different top flooring materials.
- Plywood: Sheets made of this material can be cut to size. They have one smooth side for hardwood, laminate, and other dry floor materials.
- Underlayment panels: These come in 2-by-2-foot panels and make floor installation faster.
- Soft underlay: Cork, foam, felt, and other soft underlayment materials come in rolls. They generally are not attached to the top floor materials.
- Cement board: This board is designed to be used under tile or stone flooring, but not wood flooring.
- Orient-strand board: This material is similar to plywood.
What does the underlayment do?
This material has several purposes.
- Smooths base for the top materials: It smooths out the base so that laminate flooring, hardwood flooring, and other types of top floor materials lay flat. It can keep the floor from rippling or peeling up.
- Adhesion: For ceramic tiles and stone, the underlayment provides a surface for the floor to stick to.
- Lateral stability: It adds material to the structure of the home, making a tile, vinyl, and laminate floor more sound.
- Moisture control: Moisture can travel up through the subfloor, potentially affecting hardwood flooring, vinyl, and tile. Adding a layer over the subfloor can act as a moisture barrier or a vapor barrier.
- Soften noises: Adding an additional layer between the top floor materials and the subfloor can reduce the amount of sound that gets carried through the room or home.
What types of flooring need an underlayment?
Most flooring, including laminate, vinyl, and wood, needs some sort of underlay to keep the top materials in good condition.
- Tile: This type of flooring requires solid support to prevent cracking. Cement board or CBU made from cellulose is recommended.
- Laminate: Laminate flooring should be installed over an acoustical laminate underlay, like cork or felt. Both products are designed for easy installation.
- Wood: Felt is most commonly used, though some homeowners use cork and rubber materials designed for use with wood flooring. Foam may also be recommended for areas that have high humidity, as it can keep moisture at bay.
- Engineered hardwood: For engineered wood floors, cork is recommended because it acts as a moisture barrier.
- Vinyl: Plywood is recommended for vinyl flooring.
- Carpet: Cork or rubber padding is most commonly used. There are a large variety of additional options available, including memory foam for comfort or slab rubber for high-traffic areas.