Underlay for solid wood flooring on concrete

Installing solid wood flooring on concrete surfaces can be a challenging yet rewarding task. The key to a successful and long-lasting installation lies in the choice of underlay. In this article, we will explore the importance of underlay for solid wood flooring on concrete, the types available, and the step-by-step installation process to ensure a durable and aesthetically pleasing result.

Understanding Solid Wood Flooring

Solid wood flooring adds timeless beauty and warmth to any space. However, when it comes to installing it on concrete, several challenges arise. Concrete subfloors can be uneven, prone to moisture issues, and lack the necessary cushioning. Without proper underlay, solid wood flooring may suffer from issues such as warping, cupping, and an uncomfortable feel underfoot.

Types of Underlay for Solid Wood Flooring on Concrete

Selecting the right underlay for solid wood flooring on a concrete subfloor is a critical decision that directly impacts the performance and longevity of the flooring. Here, we’ll explore three main types of underlay—Foam, Rubber, and Cork—each offering unique features and benefits to enhance the overall flooring experience.

Foam Underlay

Features and Benefits:

Foam underlay is known for its adaptability, making it suitable for various solid wood flooring applications.

As a cost-effective option, foam underlay appeals to budget-conscious homeowners without compromising on performance.

The inherent softness of foam provides a comfortable and gentle underfoot feel, contributing to a more pleasant walking experience.

Installation Process:

Foam underlay is recognized for its user-friendly installation, making it an attractive choice for both DIY enthusiasts and professionals.

Its pliable nature allows for easy cutting and shaping, ensuring a seamless fit against walls and obstacles.

Foam underlay is ideal for spaces with minimal moisture concerns. However, in environments with higher humidity levels, additional moisture protection measures may be necessary.

B. Rubber Underlay

Properties and Advantages

Rubber underlay excels in absorbing shocks, making it a preferred choice for areas with heavy foot traffic and the constant movement of furniture.

Known for its resilience, rubber underlay is highly durable, capable of withstanding the pressures of daily activities without showing signs of wear.

The dense composition of rubber provides effective sound insulation, making it an excellent option for reducing noise transfer between floors.

Installation Guidelines

Properly securing rubber underlay to the subfloor using adhesive or recommended methods ensures stability and prevents unwanted movement.

Despite its denser nature, rubber underlay is still manageable for cutting and trimming to achieve a precise fit.

Ideal Scenarios for Rubber Underlay

Rubber underlay is particularly suitable for spaces with significant foot traffic, such as hallways, living rooms, or commercial settings.

Given its exceptional sound insulation properties, rubber underlay is an ideal choice for environments where minimizing noise is a priority.

C. Cork Underlay

Environmental Benefits

Cork underlay stands out for its eco-friendly credentials, sourced from the bark of cork oak trees without harming the tree itself. Cork trees regenerate their bark, making cork a renewable resource that aligns with environmentally conscious flooring choices.

At the end of its lifecycle, cork is biodegradable, minimizing its environmental impact and contributing to sustainable living practices.

Installation Considerations

Cork underlay is best suited for smooth and even subfloors. Addressing any irregularities in the concrete subfloor is crucial before installing cork underlay.

How Cork Underlay Enhances Flooring Performance

Cork provides natural thermal insulation, promoting energy efficiency and creating a more comfortable living space. Similar to rubber, cork excels in sound absorption, effectively reducing noise transmission and creating a quieter indoor environment.

Cork’s inherent resilience adds a touch of luxury underfoot, making it an attractive choice for those seeking both comfort and sophistication.

Importance of Moisture Barrier

Concrete subfloors are susceptible to moisture, posing a significant risk to solid wood flooring. Without proper protection, moisture can lead to warping, mold growth, and a compromised installation. A moisture barrier, integrated into the underlay, acts as a protective shield, preventing moisture from reaching the solid wood flooring and ensuring its longevity.

Step-by-Step Installation Guide

Installing solid wood flooring on a concrete subfloor requires a systematic and careful approach. The following step-by-step guide outlines the key considerations and actions for a successful installation:

Preparing the Concrete Subfloor

  1. Clean the Subfloor: Before laying any underlay or flooring material, ensure that the concrete subfloor is clean and free from debris. Sweep and vacuum the surface thoroughly to create a smooth base for the underlay.
  2. Leveling the Subfloor: Address any uneven areas on the concrete subfloor. Use a leveling compound to fill in low spots and create a flat surface. This step is essential for preventing issues such as creaking and unevenness in the final flooring.
  3. Moisture Testing: Perform a moisture test on the concrete subfloor. High moisture levels can adversely affect solid wood flooring. If moisture is present, take appropriate measures, such as installing a moisture barrier, before proceeding with the underlay.

Installing the Moisture Barrier

  1. Selecting the Moisture Barrier: Choose a high-quality moisture barrier that suits the specific conditions of the room. The barrier should provide an effective shield against moisture while allowing for proper ventilation.
  2. Cutting and Placing the Barrier: Cut the moisture barrier to fit the dimensions of the room, leaving a slight overlap along the edges. Carefully lay the barrier over the prepared subfloor, ensuring full coverage. Secure the barrier in place using adhesive or tape, paying extra attention to seams.
  3. Securing the Seams: Properly secure and seal the seams of the moisture barrier. This step is crucial in preventing moisture from penetrating the subfloor and reaching the solid wood flooring.

Placing the Chosen Underlay

  1. Selecting the Underlay: Based on the type of underlay chosen (foam, rubber, or cork), follow the manufacturer’s recommendations for the specific installation process. Each underlay type may have unique features, and understanding these will contribute to a successful installation.
  2. Rolling Out the Underlay: Roll out the underlay across the entire floor, starting from one corner and working towards the opposite end. Ensure a snug fit against walls and corners, and trim any excess material if necessary.
  3. Securing the Underlay: Secure the underlay in place using the recommended methods. This may involve adhesive, double-sided tape, or another securing mechanism, depending on the underlay type. Proper attachment ensures stability and prevents movement during the solid wood flooring installation.
  4. Overlap and Seam Sealing: If using multiple rolls or sheets of underlay, overlap them according to the manufacturer’s guidelines. Seal the seams securely to maintain the integrity of the underlay system.

Securing and Acclimating the Solid Wood Flooring

  1. Placing the Solid Wood Flooring: Once the underlay is in place, carefully lay out the solid wood flooring, starting from the reference point designated during the planning phase. Follow the installation guidelines provided by the flooring manufacturer.
  2. Securing the Flooring: Secure the solid wood flooring according to the chosen installation method, which may involve nailing, gluing, or clicking the planks into place. Follow the manufacturer’s recommendations for spacing and expansion gaps.
  3. Acclimating the Flooring: Allow the solid wood flooring to acclimate to the room’s temperature and humidity. This is a critical step in preventing future issues such as warping or buckling. Follow the recommended acclimation period specified by the flooring manufacturer.

Final Installation Steps

  1. Completing the Installation: Finish the solid wood flooring installation by ensuring all planks are securely in place. Use appropriate tools to cut and fit the final pieces, paying attention to corners, doorways, and other intricate areas.
  2. Expansion Gaps and Trim Installation: Leave the necessary expansion gaps around the perimeter of the room to accommodate the natural expansion and contraction of the wood. Install baseboards or other trim to cover these gaps and provide a polished finish to the flooring.
  3. Finishing Touches: Perform any final touches, such as cleaning the installed flooring and removing any excess adhesive or debris. Follow the care and maintenance guidelines provided by both the underlay and solid wood flooring manufacturers.

Common Mistakes to Avoid

Proper execution of the step-by-step installation guide is crucial to a successful outcome. Avoid common mistakes such as skipping the moisture barrier, choosing an incompatible underlay, utilizing incorrect installation techniques, and overlooking environmental factors. Following these guidelines and avoiding pitfalls will contribute to a durable and aesthetically pleasing solid wood flooring installation on a concrete subfloor.

A. Skipping moisture barrier

Neglecting to install a moisture barrier can lead to irreversible damage to the solid wood flooring. Always prioritize this crucial step to protect against moisture-related issues.

B. Choosing the wrong type of underlay

Each type of underlay has its unique advantages and considerations. Selecting the wrong underlay for the specific environment and flooring type can compromise the overall performance and longevity.

C. Incorrect installation techniques

Improper installation of underlay and solid wood flooring can result in an uneven surface, squeaks, and other issues. Follow manufacturer guidelines and best practices to achieve a professional finish.

D. Ignoring environmental factors

Environmental conditions, such as temperature and humidity, can impact the performance of solid wood flooring. Ignoring these factors during installation may lead to future problems. Always acclimate the flooring and follow recommended environmental guidelines.

Benefits of Using Underlay for Solid Wood Flooring

A. Improved insulation

Underlay enhances the insulation properties of solid wood flooring, providing a comfortable and energy-efficient living space.

B. Enhanced sound absorption

The underlay acts as a sound buffer, reducing noise transfer between floors and rooms. This is particularly beneficial in multi-story buildings or shared living spaces.

C. Increased comfort underfoot

Walking on solid wood flooring with underlay feels more comfortable compared to direct installation on a concrete subfloor. The cushioning effect adds a touch of luxury to the overall experience.

D. Prolonged lifespan of solid wood flooring

Properly installed underlay acts as a protective layer, shielding the solid wood flooring from potential damage caused by moisture, impact, and uneven subfloors. This contributes to a longer lifespan for the flooring.

Maintenance Tips

A. Cleaning and caring for underlay

Regular cleaning of the underlay helps maintain its performance. Depending on the material, vacuuming or spot cleaning may be recommended.

B. Addressing potential issues

Keep an eye out for signs of wear, damage, or moisture-related issues. Promptly address any problems to prevent them from affecting the solid wood flooring.

C. Regular inspections and upkeep

Schedule regular inspections to ensure the underlay and solid wood flooring remain in optimal condition. Address any issues promptly to extend the life of the flooring.


In conclusion, choosing the right underlay is crucial for the successful installation and long-term performance of solid wood flooring on concrete. By understanding the challenges, selecting the appropriate underlay type, and following a meticulous installation process, homeowners can enjoy the beauty of solid wood flooring with enhanced durability and comfort. Investing time and effort into proper underlay selection and installation is a wise decision that pays off in the form of a luxurious and enduring living space.