Substrate

Underlayment for Floor Coverings and Sound Insulation for Floors

Introduction

When installing modern floor coverings in residential or commercial spaces, underlayment plays a critical role in ensuring long-term performance and comfort.

Besides acting as a stabilizing layer beneath decorative flooring such as laminate, vinyl, or engineered wood, underlayments also serve as effective soundproofing and thermal insulation barriers.

With growing demand for acoustic comfort in multi-story buildings and open-plan spaces, the choice of underlayment materials can directly affect the functionality and aesthetics of the finished flooring system.

This article explores various types of sound insulation and underlayment materials used beneath floor coverings, focusing on their composition, application, and benefits in industrial, residential, and commercial settings.

1. Types of Sound Insulation for Floor Coverings

Sound insulation under floor coverings serves two primary purposes: reducing impact noise (such as footsteps and dropped items) and airborne noise (like voices or television sound).

There are multiple materials used as underlayments for sound insulation, each with different performance properties and installation methods.

1.1. Foam-Based Underlayments

Foam underlayments are among the most common solutions used in residential flooring projects.

These are typically made from polyethylene (PE) or expanded polystyrene (EPS).

They offer basic impact sound absorption and are easy to install under floating floors like laminate.

Key benefits:

Lightweight and inexpensive
Available in rolls or sheets
Moisture-resistant options available

1.2. Rubber Underlayments

Recycled rubber underlayments are preferred in commercial and high-traffic areas due to their superior sound-dampening properties.

They are more robust than foam and provide excellent impact and airborne noise reduction.

Key benefits:

High-density composition
Long-lasting performance
Suitable for under tile, hardwood, or vinyl

1.3. Cork Underlayments

Natural cork offers excellent acoustic insulation and is environmentally friendly.

It is often used under engineered hardwood and tile flooring, delivering both thermal insulation and soundproofing benefits.

Key benefits:

Renewable and eco-friendly
Resistant to mold and mildew
Excellent for reducing impact sound transmission

1.4. Composite Underlayments

Composite underlayments combine different materials (foam, rubber, cork) to offer multi-functional performance. Some are specifically engineered to include vapor barriers or thermal insulation layers for comprehensive floor protection.

2. Foam Polyethylene Underlay for Laminate Flooring

One of the most widely used solutions in residential construction is foam polyethylene underlayment, particularly under laminate flooring.

Laminate is a floating floor system, which means it is not glued or nailed to the subfloor.

As a result, it requires a cushioning layer underneath to absorb shock, reduce sound, and smooth out minor subfloor imperfections.

2.1. Characteristics of PE Foam Underlay

Polyethylene foam underlay comes in various thicknesses and densities, typically between 2 mm and 5 mm.

Some versions are laminated with foil or include an integrated moisture barrier to prevent water vapor from damaging the laminate boards.

2.2. Benefits of Foam Underlay

Impact Sound Reduction: Helps soften footstep noise, improving acoustic comfort.
Thermal Insulation: Adds a small degree of warmth and helps reduce heat loss through the floor.
Moisture Protection: When combined with a vapor barrier, it prevents subfloor moisture from reaching the laminate.
Easy Installation: Lightweight and simple to cut, roll out, and position.

2.3. Applications

Foam underlays are suitable for bedrooms, living rooms, and light commercial areas where moderate sound insulation and floor leveling are needed.

3. Cork Underlayment for Floor Coverings

Cork underlayments are becoming increasingly popular in both residential and commercial flooring projects due to their excellent sound absorption, thermal properties, and sustainability.

3.1. Composition and Types

Cork is harvested from the bark of cork oak trees, making it a renewable resource.

It is available in rolls or sheets, typically 2 mm to 6 mm thick, and can be installed beneath hardwood, laminate, and tile floors.

3.2. Acoustic and Thermal Performance

Cork naturally absorbs sound and vibration, making it highly effective in reducing both impact and airborne noise.

It also acts as a thermal barrier, which is particularly beneficial in cold climates.

3.3. Advantages of Cork Underlay

Excellent Sound Dampening: Ideal for apartments, offices, and high-rise buildings.
Eco-Friendly: Biodegradable, renewable, and recyclable.
Durable and Long-Lasting: Maintains performance over time.
Mold and Mildew Resistant: Naturally resistant to biological degradation.

3.4. Limitations

Cost: Generally more expensive than foam alternatives.
Installation Sensitivity: Requires a smooth, clean subfloor to perform optimally.

4. Advantages of Using Sound Insulating Materials Under Floor Coverings

Properly selected underlayments not only enhance sound control but also improve the longevity and performance of floor coverings.

Here are the primary advantages of using sound insulation materials:

4.1. Acoustic Comfort

Sound insulation dramatically improves acoustic comfort, especially in multi-family residential buildings, offices, and hotels.

It helps create a quieter, more peaceful environment by reducing floor impact noise and sound transmission between levels.

4.2. Subfloor Imperfection Correction

Underlayments can help compensate for small imperfections or unevenness in the subfloor.

This reduces stress on the floor covering and prevents premature wear or cracking.

4.3. Moisture Protection

Many underlayments include moisture barriers or are moisture-resistant by design.

This is critical in areas where dampness from the subfloor could damage sensitive decorative floor materials.

4.4. Thermal Insulation

Underlayment can help reduce heat loss, particularly in rooms with concrete floors. This contributes to energy efficiency and occupant comfort.

4.5. Flooring Stability and Durability

An appropriate underlay enhances the mechanical stability of floating floors, minimizes movement, and extends the lifespan of the installed flooring.

Conclusion

Choosing the right underlayment and sound insulation for floor coverings is an essential part of modern construction and renovation projects.

Whether installing laminate in a residential apartment or tile in a commercial office, underlayments made of foam polyethylene, cork, rubber, or composite materials provide valuable benefits in sound absorption, moisture protection, and thermal insulation.

For homeowners and builders aiming to achieve acoustic comfort, energy efficiency, and flooring longevity, selecting the appropriate underlayment can make all the difference.

Among the top options, cork stands out for its sustainability and soundproofing capabilities, while foam offers an affordable and easy-to-use solution for residential needs.

Always consider the specific requirements of the space—such as foot traffic, humidity, and acoustic expectations—when choosing underlayment products for floor coverings.

With proper planning and materials, you can ensure a durable, quiet, and comfortable floor for years to come.