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A Guide to Acoustic Flooring Underlay: What You Need to Know


When it comes to creating a peaceful and comfortable living or working environment, the role of acoustic flooring underlay cannot be overstated. This essential component not only enhances the acoustic performance of your flooring by reducing noise transmission but also contributes to overall building sustainability and occupant well-being.

  • Benefits: Improves sound insulation, enhances comfort, increases floor longevity.
  • Importance: Essential for high-density living areas, commercial spaces, and any environment where noise reduction is crucial.
  • Overview: Comprises materials like rubber that effectively dampen sound vibrations.

Acoustic flooring underlay is particularly vital in multi-story buildings, where foot traffic and machinery can easily transmit sound through floors, disturbing people on lower levels. By installing the right underlay, you can mitigate this issue significantly, making it an indispensable element of modern construction and renovation projects.

Detailed infographic explaining the types of materials used in acoustic flooring underlay and their benefits in noise reduction and comfort - acoustic flooring underlay infographic infographic-line-5-steps

What is Acoustic Flooring Underlay?

Definition: Acoustic flooring underlay is a specialized material placed between the floor covering and the subfloor. Its primary purpose is to reduce the transmission of impact noise and airborne sound. Think of it as a buffer layer that helps to keep floors quieter.

Types: Acoustic underlays come in various forms, each suited for different flooring types and noise reduction needs. Common types include:
Rubber Mats: Known for their durability and excellent sound absorption.
Foam Underlays: Lightweight and great for general noise reduction.
Fiberglass Mats: Provide both noise insulation and thermal insulation.
Cork Underlays: Natural and sustainable, cork helps in reducing sound and is also an eco-friendly option.

Materials: The choice of material in an acoustic underlay influences its effectiveness and suitability for different environments. Materials commonly used include:
Rubber: Dense and heavy, rubber underlays are effective at reducing impact noise and vibrations. They are particularly useful in high-traffic areas and places with heavy equipment.
Foam: Provides a lighter, often more cost-effective option that is easy to install. Ideal for residential spaces.
Cork: Besides being eco-friendly, cork naturally reduces sound transmission and offers a bit of thermal insulation as well.

Rubber Mat and Sound Mat: These are specific types of acoustic underlays.
Rubber Mat: Typically made from recycled rubber, these mats are robust and highly effective at dampening vibrations. They are ideal for gyms, studios, and anywhere heavy equipment is used.
Sound Mat: Often made from a combination of materials like foam and rubber, sound mats are tailored to reduce airborne noise and are perfect for multi-story buildings where foot traffic noise is a concern.

By choosing the right type of acoustic flooring underlay, you can significantly enhance the comfort and livability of any space by minimizing unwanted noise. Whether it’s in a home, office, or commercial setting, these underlays play a crucial role in creating a quieter environment.

Benefits of Using Acoustic Flooring Underlay

When considering renovations or new constructions, one often overlooked but crucial component is the acoustic flooring underlay. This addition to your flooring structure offers multiple advantages, from noise management to comfort enhancement. Here’s why incorporating an acoustic underlay is more than just a building requirement—it’s a substantial improvement to any living or working space.

Noise Reduction

One of the primary benefits of using an acoustic underlay is its ability to significantly reduce noise levels. Whether it’s the sound of footsteps, moving furniture, or ambient noise from external sources, an underlay helps in dampening these sounds, creating a quieter and more peaceful environment. This feature is particularly beneficial in multi-level buildings, such as apartments or office spaces, where noise from upper floors can be a disturbance.


Walking on a floor with acoustic underlay feels different—it’s more comfortable. The underlay provides a softer surface, which can be easier on your feet and joints. This added layer not only improves the feel of the floor underfoot but also adds a level of warmth, making it especially beneficial in colder climates.

Energy Efficiency

While often overlooked, acoustic underlays can contribute to the energy efficiency of a space. They act as an additional layer of insulation, keeping rooms warmer in the winter and cooler in the summer. This can help reduce the need for excessive heating and cooling, leading to lower energy bills and a smaller carbon footprint.

Impact Insulation

The ability of acoustic underlays to provide impact insulation cannot be understated. They absorb shocks and reduce the vibrations caused by walking or dropping objects on the floor. This quality is measured by the Impact Insulation Class (IIC) rating of the underlay; higher IIC ratings indicate better performance in minimizing sound transmission. High-quality underlays, like those made from rubber, boast excellent IIC ratings, making them ideal choices for high-traffic areas or in buildings where noise reduction is paramount.

By integrating an acoustic flooring underlay, you not only enhance the usability and comfort of your space but also contribute to its overall energy efficiency and sound quality. Whether you’re updating an old office or designing a new home, consider the long-term benefits of installing an effective underlay. It’s an investment in comfort, quiet, and sustainability.

How to Choose the Right Acoustic Flooring Underlay

Choosing the right acoustic flooring underlay can feel overwhelming, but it’s crucial for achieving the best performance in terms of soundproofing and comfort. Here’s how you can make an informed decision based on thickness, material, density, compatibility, and specific products like Iso-Step® and Impact Barrier QT™.


The thickness of the underlay impacts its ability to absorb sound. Generally, thicker underlays provide better sound insulation. For instance, Iso-Step® underlayment is available in various thicknesses ranging from 2 mm to 12 mm. Thicker options are particularly beneficial in areas where high levels of noise reduction are needed.


The material of the underlay also plays a significant role in its effectiveness. Rubber is a popular choice due to its natural sound-dampening properties. Both Iso-Step® and Impact Barrier QT™ are made from recycled rubber, which not only helps in soundproofing but also contributes to environmental sustainability.


Density is another critical factor. Higher density underlays are better at reducing noise because they can absorb and block more sound waves. Products like Impact Barrier QT™ offer variations in density, allowing you to choose the best option based on the level of noise reduction you need.


Ensure the underlay is compatible with your flooring type. Whether you have hardwood, vinyl, or carpet, the underlay should work in tandem with the floor to provide the best results. For example, Iso-Step® underlayment is compatible with a wide range of flooring finishes including ceramic tile, hardwood, and luxury vinyl tile.

Iso-Step® and Impact Barrier QT™

When considering specific products, Iso-Step® and Impact Barrier QT™ are among the top choices for acoustic underlays. Iso-Step® is engineered to provide superior impact sound insulation and can be installed over wood or concrete subfloors. It’s also fast to install and compatible with most floor finishes.

Impact Barrier QT™ is designed to offer exceptional noise reduction and is easy to install. It’s available in different densities to meet varying needs and is made from non-toxic, recycled rubber, making it a safe and eco-friendly option.

By considering these factors—thickness, material, density, and compatibility—and choosing between top-notch products like Iso-Step® and Impact Barrier QT™, you can effectively enhance the acoustic performance of your flooring. This not only improves the comfort and usability of your space but also contributes to a quieter and more peaceful environment.

Installation Techniques for Acoustic Flooring Underlay

Proper installation of acoustic flooring underlay is crucial for maximizing its effectiveness in noise reduction and durability. Here’s how you can ensure that your underlay is installed correctly, whether you’re doing it yourself or hiring a professional.


Before you begin the installation, it’s important to prepare the area thoroughly:

  • Clear the Area: Remove all furniture and any existing flooring if necessary. This includes pulling up old carpet, laminate, or tiles.
  • Clean and Dry: Ensure the subfloor is clean, dry, and smooth. Any dirt, moisture, or debris can affect the adhesion and performance of the underlay.


There are generally two main techniques for installing acoustic flooring underlay: glued and loose laid.

Glued Installation

  1. Apply Adhesive: Using a recommended adhesive, apply it evenly across the subfloor. For products like Iso-Step®, specific adhesives such as Iso-Step® Quick Cure Soundproofing Underlayment Adhesive may be recommended.
  2. Lay the Underlay: Roll out the underlay carefully over the adhesive, ensuring there are no creases or bubbles.
  3. Pressure: Once laid, press down on the underlay to ensure it bonds well with the adhesive and the subfloor.

Loose Laid Installation

  1. Roll Out: Simply roll out the underlay across the subfloor. Make sure the edges meet but do not overlap.
  2. Cut to Fit: Trim any excess material at the edges and around obstacles like columns or doorways.
  3. Secure the Seams: Tape the seams between rolls with a strong, durable tape to prevent shifting and to keep moisture from penetrating the underlay.

Professional Tips

  • Subfloor Compatibility: Always check that the underlay is compatible with the type of subfloor you have, whether it’s concrete or wood.
  • Acclimatization: Allow the underlay material to acclimatize to the room’s temperature and humidity before installation to prevent expansion or contraction post-installation.
  • Overlapping: For some types of underlay, overlapping the edges slightly before taping them together can provide better sound insulation.
  • Testing: After installation, it’s a good idea to test a small area by walking over it and listening for any movement or noise that might indicate the underlay isn’t securely installed.

By following these steps and tips, you can effectively install your acoustic flooring underlay to enhance the comfort and soundproofing qualities of your living or workspace. This preparation and careful installation ensure that the underlay performs at its best, reducing noise and making your environment more enjoyable.

Common Applications and Best Practices

When selecting and installing acoustic flooring underlay, it’s crucial to consider its application across various settings such as home gyms, apartments, hotels, and different types of flooring like vinyl, laminate, and hardwood. Here’s how to apply acoustic flooring underlay effectively in these common scenarios:

Home Gyms

In home gyms, the underlay must withstand heavy equipment and high-impact activities. A thicker, denser underlay, like the dB4 Max Acoustic Floor Underlayment, is ideal as it reduces the noise from dropped weights and intense workouts, protecting the floor beneath and minimizing disturbance to other rooms.


For apartment dwellers, acoustic flooring underlay is essential in minimizing footfall noise and music that can easily transmit to units below. The use of a high-performance underlay like Impact Barrier QT™ ensures a significant reduction in sound transmission, enhancing privacy and comfort for all residents.


In hotels, where guest comfort is paramount, reducing noise between floors can significantly enhance guest satisfaction. An effective acoustic underlay not only improves sound quality but also adds a luxurious feel underfoot, crucial for areas with high foot traffic like hallways and rooms.

Vinyl, Laminate, and Hardwood Floors

  • Vinyl: For vinyl flooring, choose a moisture-resistant underlay that also provides sound insulation. The underlay should be thin enough to not raise the floor height excessively while providing stability.

  • Laminate: Laminate floors benefit from a dense, foam-based underlay that reduces the tapping sound inherent in this type of flooring. It also helps in smoothing out minor subfloor imperfections.

  • Hardwood: Hardwood floors require a high-quality underlay to prevent moisture and to reduce the hollow sound that can occur. Rubber-based underlays are often recommended for their superior sound dampening properties and long-term durability.

Best Practices

  • Proper Measurement and Installation: Ensure that the underlay fits perfectly to avoid gaps and overlaps, which can compromise its effectiveness. It’s often best to have a professional installer do the work to ensure optimal performance.

  • Choosing the Right Thickness and Density: The effectiveness of an acoustic underlay often depends on choosing the right thickness and density for the specific application. Thicker and denser underlays generally offer better soundproofing, especially in high-impact areas.

  • Consider the Environment: In areas with high humidity or risk of moisture, opt for underlays with built-in moisture barriers to prevent mold and mildew growth.

By understanding the specific needs of each setting and choosing the right acoustic flooring underlay, you can significantly enhance the functionality and comfort of any space. Whether it’s a bustling hotel or a private home gym, the right underlay not only improves acoustics but also extends the life of the floor above.

Frequently Asked Questions about Acoustic Flooring Underlay

What Underlayment Is Best for Soundproofing?

When it comes to soundproofing, not all underlayments are created equal. The Impact Barrier QT™ and Iso-Step® are top choices for their superior soundproofing qualities. Impact Barrier QT™ is particularly effective due to its composition of 92% recycled rubber, which helps to dampen noise and reduce sound transmission. This makes it an excellent option for both residential and commercial settings.

Iso-Step® underlayment is another robust option designed to minimize impact noise and airborne sound. It works well over various subfloors and under numerous types of floor finishes, making it versatile for different installation scenarios.

How Do I Reduce Footstep Noise From Upstairs?

To reduce footstep noise from an upper floor, consider two effective strategies: installation methods and rug placement. Installing a high-quality acoustic underlayment like Iso-Step® directly beneath the flooring can significantly diminish noise by breaking the sound transmission path. Additionally, placing rugs or carpets over the floor can absorb sound, further reducing the noise heard from footsteps upstairs. Combining both underlayment and rugs provides a dual layer of soundproofing that is particularly effective.

How Can I Reduce Noise In My House With Hardwood Floors?

Hardwood floors can amplify sounds, making actions like footsteps or dropped objects sound much louder. To combat this, you have several options:

  • Underlayment choices: Installing a dense, sound-absorbing underlayment such as Impact Barrier QT™ beneath your hardwood floors can dramatically reduce noise levels. This underlayment not only softens the sounds of footsteps but also helps in minimizing the transfer of sound to rooms below.

  • Floor joist isolators: These are specially designed to decrease vibrations by creating a buffer between the floor joists and the subflooring. By installing these isolators, you can significantly cut down on the sound vibrations that travel through the building’s structure, which is often the cause of creaking and other noise issues associated with hardwood floors.

By addressing these key areas with the right products and installation techniques, you can enjoy quieter, more peaceful living spaces. Whether you’re dealing with noisy upstairs neighbors or your own family’s foot traffic, the right acoustic flooring underlay can make a significant difference.


As we wrap up our guide on acoustic flooring underlay, it’s clear that this isn’t just about noise reduction—it’s about creating sustainable and comfortable environments. At Rubcorp, we are committed to sustainability in every aspect of our business, from the products we create to the methods we recommend for installation.

Acoustic flooring underlay plays a crucial role in building sustainable environments. By mitigating noise pollution and enhancing the livability of spaces, these solutions contribute significantly to the well-being of occupants. This is especially important in densely populated settings like apartments, hotels, and commercial buildings, where the quality of life can be heavily impacted by noise.

Moreover, our commitment to sustainability is reflected in our choice of materials. Many of our products, like the acoustic rubber flooring, are made from recycled materials, reducing waste and promoting the reuse of resources. This not only supports environmental sustainability but also ensures that our customers are installing products that are safe for both their health and the planet.

At Rubcorp, we believe that sustainable practices don’t just end at the product level. We encourage all our customers to consider the full lifecycle of their building materials. From selection and installation to long-term maintenance, every step is an opportunity to make choices that benefit both the immediate environment and the broader world.

In conclusion, choosing the right acoustic flooring underlay is more than a technical decision—it’s a step towards a more sustainable and quiet lifestyle. By selecting Rubcorp products, you’re not just installing a floor; you’re investing in a solution that respects the environment and enhances the quality of life for all occupants. Connect with our team to find out how we can help you achieve the results you desire, and join us in building a more sustainable, quieter world.

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Creative Director, Rubcorp Distribution, LLC

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