Understanding the Role of Underlay in Flooring Installation

May 9, 2023

Installing flooring is a crucial aspect of home construction and renovation projects. One key component of this process is the underlay, which plays a role in the floor's overall performance, durability, and aesthetics. In Malaysia, the underlay is especially important, given the country's tropical climate, which can affect the lifespan of the floor. In this article, we will delve into the role of underlay in Malaysian flooring installations, the types of underlay available, and how to properly install them to avoid common mistakes and optimise your flooring's lifespan.


The importance of underlay in flooring installation

Underlay serves several purposes in a flooring installation. Some of the main benefits include:

  • Providing a smooth and even surface: Underlay helps to create an even and level surface for the flooring materials to be installed on. It can correct minor imperfections in the subfloor, ensuring a uniform surface for the finished floor.
  • Enhancing comfort: Underlay can provide additional cushioning and support for the flooring, contributing to a more comfortable underfoot experience.
  • Improving acoustics: Quality underlay can help reduce sound transmission between floors, providing a quieter living environment.
  • Enhancing thermal insulation: Underlay can help insulate the floor, keeping the room warmer in cold weather and cooler during the hot Malaysian climate.
  • Protecting the floor: Underlay acts as a barrier between the subfloor and the flooring material, preventing moisture, dirt, and other damaging elements from reaching the finished floor.
  • Extending the lifespan of the floor: The additional support and protection provided by the underlay can help extend the life of your flooring materials, reducing the need for frequent replacements.


Types of underlay for flooring installations

Several types of underlay are available for use in Malaysia. Some of the most common types include:

  • Foam underlay: This is a popular and affordable option, offering basic cushioning and support for various flooring types. Foam underlay is suitable for laminate and engineered wood flooring.
  • Rubber underlay: Rubber underlay is denser and more durable than foam, providing excellent sound absorption and thermal insulation. It is suitable for various flooring types, including carpet, laminate, and engineered wood flooring.
  • Felt underlay: Felt underlay is made from recycled fibres and offers a high level of sound absorption and thermal insulation. It is suitable for carpet, laminate, and engineered wood flooring.


Tips for proper underlay installation

To maximise the benefits of your underlay and avoid common mistakes, follow these tips for proper installation:

  • Choose the right underlay: Select an underlay that is compatible with your flooring material and suitable for the specific needs of your space, such as sound absorption or moisture resistance.
  • Prepare the subfloor: Before installing the underlay, ensure the subfloor is clean, dry, and level. Repair any cracks or uneven areas, and remove any debris or dust that could affect the underlay's performance.
  • Measure and cut the underlay: Measure your room carefully and cut the underlay to fit the space, leaving a small gap around the edges for expansion. Using the correct underlay thickness is crucial, as too thick or too thin can negatively impact the flooring's performance.
  • Install the underlay: Unroll the underlay across the subfloor, starting at one corner of the room and working your way across. If you're using multiple rolls, make sure to butt the seams together without overlapping. Use a suitable adhesive or tape to secure the seams and prevent them from shifting during the flooring installation.
  • Install a moisture barrier: In humid climates like Malaysia, it's essential to install a moisture barrier, such as a polythene sheet, between the underlay and the subfloor. This will help prevent moisture-related issues, such as mould and mildew growth, that can damage your floor.
  • Install the flooring: Once the underlay is in place, you can proceed with installing your chosen flooring material. Be sure to follow the manufacturer's instructions for proper installation techniques and spacing.


Common mistakes to avoid when installing underlay

To ensure the best results from your underlay installation, be aware of these common mistakes and take steps to avoid them:

  • Overlapping seams: As mentioned earlier, overlapping the seams of the underlay can create an uneven surface and cause issues with the flooring installation. Always butt the seams together and secure them with adhesive or tape.
  • Inadequate expansion gaps: Failing to leave an expansion gap around the edges of the room can cause the flooring to buckle or warp over time. Ensure there is a small gap around the perimeter to accommodate natural expansion and contraction.
  • Skipping the moisture barrier: Neglecting to install a moisture barrier in humid environments can lead to moisture-related problems down the line. Always include a moisture barrier to protect your flooring investment.
  • Using the wrong type or thickness of underlay: Using an incompatible or incorrect thickness of underlay can compromise the performance and lifespan of your floor. Be sure to select the appropriate underlay for your flooring type and follow the manufacturer's recommendations for thickness.


Maintenance and care for your underlay and flooring

To keep your floor looking and performing its best, it's essential to maintain both the flooring material and the underlay beneath it. Here are some tips for maintaining and caring for your floor:

  • Regular cleaning: Sweep, vacuum, or mop your flooring regularly to remove dirt, dust, and debris. Use cleaning products specifically designed for your flooring material and avoid harsh chemicals or abrasive tools that can damage the surface.
  • Address spills promptly: Clean up any spills or moisture immediately to prevent damage to the flooring and underlay. Be particularly mindful of this in humid climates like Malaysia, where moisture can quickly lead to mould and mildew issues.
  • Use appropriate furniture protectors: Place felt pads or furniture protectors under the legs of heavy furniture to prevent dents and scratches on your floor. This will also help distribute the weight evenly and protect the underlay from excessive compression.
  • Manage humidity levels: Use a dehumidifier or air conditioning to maintain a comfortable indoor humidity level. This will help protect your floor and underlay from moisture-related problems and prolong their lifespan.
  • Inspect your floor periodically: Regularly check your floor for signs of wear, damage, or moisture issues. If you notice any problems, address them promptly to prevent further damage and maintain the integrity of your flooring and underlay.
  • Follow manufacturer's guidelines: Adhere to the manufacturer's recommendations for maintaining and caring for your specific flooring material and underlay. This will help ensure optimal performance and longevity.



The role of underlay in Malaysian flooring installations cannot be overstated. By understanding its importance and purpose, selecting the correct type of underlay for your flooring material, and following proper installation and maintenance techniques, you can significantly enhance your floor's performance, durability, and aesthetics. Remember the tips and common mistakes to avoid when installing underlay, and you'll be on your way to a comfortable, functional, and long-lasting floor.