When installing wooden flooring, one of the most important accessories to consider is the underlayment. Underlayment is a thin, foam or felt material that is installed between the subfloor and the wooden planks, providing a range of benefits including moisture protection, sound insulation, and added stability. But with so many different types of underlayment available, how do you choose the right one for your wooden installation? In this insightful blog post, we’ll explore the key factors to consider when selecting underlayment for your wooden flooring project.

Factor 1: Moisture Protection

One of the primary functions of underlayment is to provide moisture protection for your wooden flooring. Even though wood is moisture-resistant, it’s not completely waterproof, and excess moisture can cause issues like warping, cupping, or even mold growth over time. When choosing an underlayment for your wooden flooring, look for options that feature a moisture barrier or vapor retarder to prevent moisture from seeping through the subfloor and into the wooden planks.

If you’re installing wood in a high-moisture area like a bathroom or kitchen flooring, it’s especially important to choose an underlayment with excellent moisture protection. Look for options that feature a high-quality moisture barrier, such as a polyethylene film or a rubberized membrane, to ensure maximum protection against moisture damage.

Factor 2: Sound Insulation

Another important function of underlayment is to provide sound insulation for your wooden flooring. wooden planks can be noisy underfoot, especially in multi-story homes or apartments, and the right underlayment can help to reduce noise transmission and create a quieter, more peaceful living environment.

When choosing an underlayment for sound insulation, look for options with a high Sound Transmission Class (STC) rating, which indicates how well the material reduces airborne noise. A higher STC rating means better sound insulation, so aim for an underlayment with an STC rating of at least 50 for optimal noise reduction.

Factor 3: Thermal Insulation

In addition to moisture protection and sound insulation, some underlayments also provide thermal insulation for your wooden flooring. This can be especially beneficial in colder climates or in rooms with poor insulation, as it can help to keep your floors warm and comfortable underfoot.

When choosing an underlayment for thermal insulation, look for options with a high R-value, which indicates the material’s resistance to heat flow. A higher R-value means better thermal insulation, so aim for an underlayment with an R-value of at least 2.0 for optimal warmth and comfort.

Factor 4: Compatibility with Radiant Heating

If you’re installing wooden flooring over a radiant heating system, it’s essential to choose an underlayment that is compatible with the system. Some underlayments can interfere with the heat transfer from the radiant heating tubes or wires, reducing the system’s efficiency and effectiveness.

When choosing an underlayment for use with radiant heating, look for options that are specifically designed for this purpose. These underlayments typically feature a lower thermal resistance, allowing heat to pass through easily and efficiently, while still providing the necessary moisture protection and sound insulation.

Factor 5: Thickness and Density

Finally, when choosing an underlayment for your wooden flooring, it’s important to consider the thickness and density of the material. A thicker underlayment can provide better sound insulation and thermal insulation, but it may also raise the height of your flooring and create issues with transitions or door clearance.

On the other hand, a denser underlayment can provide better stability and support for your wooden planks, preventing any issues with unevenness or sagging over time. Look for an underlayment with a density of at least 25 pounds per cubic foot (PCF) for optimal stability and performance.


By considering these key factors and choosing the right underlayment for your specific needs and preferences, you can ensure a successful and long-lasting wooden flooring installation. Whether you’re looking for maximum moisture protection, optimal sound insulation, or enhanced thermal insulation, there’s an underlayment out there that can help you achieve your goals and create a beautiful, comfortable, and durable flooring surface.