An underlayment is a layer of material placed directly beneath the outer surface of a floor, roof or even within walls, serving a multitude of purposes depending on the specific type and location. This essential element in construction provides various essential functions including moisture control, insulation, sound reduction, and structural reinforcement, among other things. It helps to ensure durability and longevity of the outer surface, such as shingles, tiles, or hardwood.

The materials used for underlayment can range from plywood to more advanced substances like silicone and acoustic underlayment, each offering unique advantages suited for different needs. Understanding the role of underlayment can significantly impact the quality and effectiveness of construction and renovation projects and even in the installation of hardwood floors.

Read more as we’ll delve into the details about hardwood floor underlayment in today’s article.

The Definition And Purpose

A hardwood floor underlayment is a semi-flexible, often cushion-like material that is installed beneath hardwood flooring to provide a supportive and protective layer. The primary purpose of an underlayment is to provide a smoother, more durable surface for the hardwood flooring. It helps to reduce noise, prevent moisture ingress, and offer thermal insulation by creating a barrier between the floor and subfloor.

The underlayment can offer a significant improvement to the overall longevity and performance of the hardwood flooring. Moreover, it adds a degree of comfort to the walking surface by providing a slight ‘give’. Hence, installing underlayment is a critical process in the installation of hardwood flooring.

Why Is Underlayment Important For Hardwood Floors?

Placing a layer of underlayment before installing hardwood flooring is essential because of the following reasons:

1. Protecting The Subfloor

Protecting the subfloor is a vital aspect of home maintenance often overlooked. The subfloor acts as a foundation to the visible flooring, effectively bearing the weight of furniture and regular traffic. Protecting it from moisture, pests, and structural damage not only extends the lifespan of the entire floor but can prevent costly replacements.

Methods such as vapor barriers, underlayment, or sealants can be used effectively. Also, regular inspections for signs of damage, like warping or sagging, ensure the subfloor remains structurally sound and aids in keeping the charm and strength of your home intact.

2. Enhancing The Performance Of Hardwood Flooring

Underlayments play a crucial role in enhancing the performance and longevity of hardwood flooring. They provide an essential foundation, reducing sound, providing insulation, and offering a certain level of comfort underfoot.

More importantly, underlayments facilitate a smoother installation process because they create an even base for the hardwood flooring. They also protect the flooring from moisture damage, which is a common problem in floor installations.

In essence, using an underlayment not only guarantees a top-quality hardwood floor finish, but it also prolongs its lifespan, ensuring that its aesthetic appeal remains intact.

3. Improving Sound Absorption

Installing an underlayment can significantly improve a room’s sound absorption characteristics. This thin layer of material, typically made from foam or rubber, is placed beneath the main flooring surface and acts as a sound barrier.

Not only does it minimize the transmission of sound waves through the floor, creating a quieter living environment, but it can also reduce the hollow and echoey sounds often experienced with hard floors such as laminate or wood.

4. Minimizing Moisture Damage

Underlayments are a crucial component in hardwood flooring installations. These are specially designed layers positioned between the floor and the hardwood that offer a myriad of benefits. Primarily, they serve to minimize moisture damage, thus considerably extending the lifespan of the floor.

They achieve this by providing a barrier that prevents moisture from seeping up into the hardwood, which can cause warping, rotting, and other forms of damage. Consequently, underlayments help maintain the beauty of the hardwood while simultaneously protecting your investment from potential harm.

5. Providing Thermal Insulation

Underlayment offers significant thermal insulation benefits. This insulation helps in maintaining a consistent temperature across the floor during temperature fluctuations, by reducing heat loss in winters and heat gain in summers. The underlayment acts like a barrier, preventing heat from directly penetrating through the hardwood, therefore promoting energy efficiency.

The use of a quality underlayment not only enhances the lifespan of your hardwood floor but also contributes to a more comfortable and energy-efficient home environment.

Types Of Underlayment For Hardwood Flooring

Cork Underlayment

This is a material designed to provide added comfort, thermal insulation, and sound control under a wood flooring system. It’s derived from the bark of the cork oak tree, making it a sustainable and eco-friendly option. Customarily, it comes in sheets or rolls and is installed directly on the subfloor before the hardwood slabs are laid. This extra layer absorbs shock, reduces noise transmission, helps to insulate your floors and can even prevent damage from minor subfloor irregularities.

Foam Underlayment

This material is a protective layer inserted between the subfloor and hardwood flooring during installation. Typically, it’s made of a thin, foam-like material which helps to absorb sound, reduce wear and tear, and provide a small amount of insulation. This underlayment works as a shock and moisture absorber, protecting the hardwood from potential damages and increasing its longevity.

Furthermore, it smoothens minor subfloor imperfections, ensuring a flat, stable base for the hard floor above.

Plywood Underlayment

A plywood underlayment is a layer of material that is installed directly beneath the surface hardwood floor covering in a building or house, such as tile, carpet, linoleum, or wood. The primary purpose of this underlayment is to provide a smooth, flat surface for the floor covering. It assists in absorbing the pressure and wear inflicted on the floor due to everyday usage, thus extending the life of the floor.

The plywood underlayment also acts as a moisture barrier and helps reduce any sound transmission. It is essential to choose the right thickness and type of plywood to ensure durability and prevent visible seams or ridges on the finished flooring. 

Engineered Hardwood Flooring Underlayment

This is a crucial element in the installation process of engineered hardwood flooring. This underlayment, often made of foam, cork, or rubber, serves multiple functions. Firstly, it acts as a cushioning barrier between the hardwood and the subfloor, helping to reduce noise and vibration, making your flooring more comfortable to walk on. Secondly, it provides thermal insulation, keeping the room warmer during cold weather.

A quality underlayment also offers a protective layer that can prevent moisture damage, extending the life of your flooring. It can help to smooth out minor subfloor imperfections, ensuring a flawless finish for your engineered hardwood flooring.

Choosing The Right Installer To Work On The Underlayment For Your Hardwood Flooring

Choosing the right installer for your hardwood flooring underlayment is pertinent to the longevity and aesthetics of your floors. This job requires expertise and precision, and therefore demands the services of a seasoned professional. The ideal installer should have vast experience working with various types of hardwood floors and underlayments. They should understand the functionality of different underlayments and their influence on the flooring above. It’s wise to look for customer testimonials and reviews before choosing your installer.

Remember, the quality of the workmanship is directly proportional to the performance of your flooring. So, don’t rush this decision – take your time to research, verify, and then hire the best installer for your needs.


In conclusion, the underlayment material is a crucial component in the installation of hardwood flooring. It performs several essential roles, including providing stability, noise reduction, moisture protection and underfoot comfort. The right underlayment can also significantly enhance the longevity and performance of the hardwood flooring, as well as alleviate minor imperfections of the subfloor.

With a variety of types available, the choice significantly depends on the specific requirements of the flooring and the conditions of the installation site. Therefore, careful selection and installation of underlayment material is an indispensable step towards ensuring the durability and functionality of hardwood flooring.