The Role of Underlayment in Moisture Control for Malaysian Buildings

May 12, 2023

Malaysia is known for its hot and humid climate, with high humidity levels and heavy rainfall throughout the year. Thus, moisture control is a critical consideration for buildings to ensure the structures' safety, comfort, and durability. One effective way to manage moisture in buildings is by using an underlayment system. This article will discuss the importance of underlayment in moisture control for Malaysian buildings, its various types, and how it can protect against moisture intrusion and help prevent mould and other moisture-related problems.


Importance of Moisture Control in Buildings

In a country like Malaysia, where the relative humidity often exceeds 80%, moisture control is a crucial aspect of building design and construction. Failure to address moisture-related issues can lead to several problems, including:

  • Mould and mildew growth: Excessive moisture encourages the growth of mould and mildew, which can cause unpleasant odours, trigger allergies, and even lead to structural damage.
  • Material deterioration: Prolonged exposure to moisture can weaken building materials, such as wood and metal, reducing their lifespan and compromising the structural integrity of the building.
  • Reduced thermal comfort: High humidity levels can make indoor spaces feel hotter and more uncomfortable, increasing the demand for air conditioning and raising energy costs.
  • Condensation: When warm, moist air comes into contact with colder surfaces, it can lead to condensation, causing water damage and promoting the growth of mould and mildew.


Underlayment: A Solution for Moisture Control

Underlayment is a layer of material installed beneath the primary flooring material, designed to provide additional protection against moisture intrusion. Underlayment can be made from various materials, including synthetic polymers, rubber, and felt, each offering different levels of water resistance and other benefits. The primary functions of underlayment in moisture control include:

  • Providing a barrier against moisture infiltration: By acting as a barrier between the primary building materials and the external environment, underlayment prevents the entry of moisture, ensuring the durability and longevity of the structure.
  • Regulating indoor humidity: Underlayment can help regulate indoor humidity levels by preventing excessive moisture from entering the building, thus maintaining a comfortable indoor environment.
  • Protecting the primary building materials: As an additional layer of protection, underlayment helps prevent the primary building materials from coming into direct contact with moisture, reducing the risk of material deterioration.


Types of Underlayment for Moisture Control

Several types of underlayment materials are available, each with its unique characteristics and benefits:

  • Synthetic Underlayment: This type of underlayment is made from synthetic polymers, such as polythene or polypropylene, and offers excellent moisture resistance, durability, and strength. Synthetic underlayment is lightweight and easy to install.
  • Rubber Underlayment: Made from recycled rubber materials, rubber underlayment provides excellent moisture resistance, sound absorption, and thermal insulation. It is an environmentally friendly option that can be used in a wide range of applications.


Choosing the Right Underlayment for Your Building

Here are some key considerations to help you select the appropriate underlayment for your building:

  • Compatibility with primary building materials: Ensure that the underlayment is compatible with the primary materials used in your building, such as wood, metal, or concrete. Some underlayment materials may react negatively with certain primary materials, leading to decreased performance or even damage.
  • Application and location: Consider the specific application of the underlayment and the location of the building, as areas with higher rainfall or humidity may require more robust moisture protection.
  • Building regulations and standards: Be aware of the building regulations and standards applicable in Malaysia, which may dictate specific underlayment requirements for moisture control.
  • Cost and installation: Evaluate the cost of the underlayment material and the installation process. Some materials may be more expensive or challenging to install but may provide better moisture protection in the long run.


Preventing Mould and Moisture-related Problems with Underlayment

Underlayment is vital in preventing mould and other moisture-related problems in buildings by providing an effective barrier against moisture intrusion. By preventing excessive moisture from entering the building, underlayment reduces the risk of mould, mildew growth, and material deterioration. In addition to using underlayment, proper building design and maintenance are essential in preventing moisture-related problems. Some strategies to consider include:

  • Adequate ventilation: Ensuring proper ventilation throughout the building helps regulate indoor humidity levels and prevents moisture accumulation.
  • Proper drainage: Designing a suitable drainage system around the building can help prevent water from pooling and infiltrating the structure.
  • Regular maintenance: Conducting regular inspections and maintenance of the building's envelope, including the roof, walls, and foundation, can help identify and address any potential moisture issues before they escalate.


Challenges in Implementing Underlayment Systems in Malaysian Buildings

While underlayment systems offer significant benefits for moisture control in buildings, there are also several challenges in implementing these systems:

  • Awareness and education: Many building owners, designers, and contractors may not be fully aware of the importance of underlayment in moisture control or the specific requirements for their projects. Increased education and awareness efforts are necessary to ensure that underlayment systems are correctly specified and installed.
  • Regulatory compliance: It is essential to comply with local building regulations and standards when selecting and installing underlayment systems. Ensuring compliance can sometimes be challenging, especially if regulations are complex or frequently updated.
  • Installation expertise: Properly installing underlayment systems is crucial for their effectiveness in moisture control. Building professionals must be adequately trained and experienced in installing various underlayment materials to ensure the desired performance.



By understanding the importance of underlayment, its various types, and how to select the right underlayment for your building, you can ensure the longevity and performance of your structure in Malaysia's challenging climate conditions. Remember, proper building design, maintenance, and the use of appropriate underlayment materials are critical components in the fight against moisture-related issues in buildings.