Can You Use Roofing Felt Under Laminate Flooring

Laminate flooring requires an effective underlayment to provide moisture protection, sound dampening, and a smooth, stable surface. Roofing felt, a durable mineral-saturated asphalt product, is sometimes considered as an underlayment. This article examines whether roofing felt is suitable for laminate, the risks involved, and better alternatives that align with modern installation practices in the United States.

What Is Roofing Felt

Roofing felt, also known as tar paper, is traditionally used in roofing and some construction applications as a moisture barrier. It comes in various weights and weatherproofing qualities, often made from asphalt-saturated organic fibers or fiberglass. In roofing, its role is to shed water and provide a base for shingles. When considered for laminate flooring, the material’s properties—rigidity, breathability, and moisture behavior—do not align with typical underlayment requirements for indoor flooring.

Is Roofing Felt Suitable for Laminate Flooring

In most cases, roofing felt is not recommended as an underlayment for laminate flooring. Laminate flooring relies on a specifically engineered underlayment to manage moisture, reduce noise, and create a stable, smooth surface. Roofing felt can introduce moisture retention, odor, or chemical interactions with the laminate’s backing and adhesive, potentially compromising the floor over time. Manufacturer guidelines for laminate products commonly specify materials such as foam underlayment, cork, or film-faced poly underlayment, rather than roofing felt.

There are exceptions where a protective layer or certain blends might be used briefly during construction, but these are not intended for long-term residential use. Homeowners should consult the laminate manufacturer’s installation instructions to confirm compatible underlayment options. Ignoring these guidelines can void warranties and lead to performance issues such as squeaks, gaps, or delamination.

Moisture and Vapor Considerations

Moisture management is crucial for laminate flooring, which is more sensitive to humidity and moisture than many other flooring types. Proper underlayment acts as a vapor barrier and helps prevent moisture from seeping into the core and subfloor. Roofing felt’s moisture handling characteristics are not optimized for indoor humidity control and may allow trapped moisture in some installations. Additionally, the felt’s thickness and compressibility can affect the laminate’s surface feel and stability, creating unevenness or a soft underfoot sensation.

• Vapor retarders: Many laminate products require a vapor barrier to protect the subfloor and to prevent swelling of the core. The underlayment should provide an appropriate vapor retardency without trapping moisture.
• Humidity considerations: In basements or humid climates, using an underlayment specifically designed for laminate is essential to maintain long-term integrity.
• Radiant heat: If a radiant heat system is present, manufacturer-approved underlayments are necessary to ensure compatibility and performance.

Alternatives To Roofing Felt

Several underlayment options are widely recommended for laminate flooring in U.S. homes. Each serves moisture control, sound reduction, and comfort in different ways:

• Foam underlayment: A common choice for typical installations, offering sound dampening and a small amount of cushioning. Ensure it includes a moisture barrier if the subfloor is concrete or prone to moisture.
• Cork underlayment: Natural sound insulation and comfortable feel; often suitable for quieter rooms and HVAC conditions. Some cork products include vapor barriers for added protection.
• Foil-faced poly or film underlayment: Provides an effective vapor barrier and is compatible with many laminate products, particularly where a dry, stable surface is needed.
• Combination underlayment: Some products combine moisture protection, sound dampening, and slight thermal insulation, designed specifically for laminate floors.
• Self-adhesive or tacky underlayment: Useful for quick installs on plywood subfloors but verify compatibility with the laminate brand and climate.

Installation Tips for Laminate Flooring

Following best practices in installation helps maximize performance and warranty coverage. The core principles include planning, moisture assessment, and proper seam treatment.

• Check subfloor conditions: The subfloor should be dry, clean, and level. Address any moisture sources before laying the underlayment.
• Choose manufacturer-approved underlayment: Always select underlayment recommended by the laminate manufacturer for your specific product and climate zone.
• Leave expansion gaps: Maintain the specified expansion gaps around walls and fixed objects to accommodate seasonal movement.
• Seal moisture-prone spaces: Use appropriate sealants around plumbing penetrations and in basements to minimize moisture migration into the underlayment.
• Store materials properly: Acclimate laminate products per manufacturer guidelines and avoid storing them in damp or humid environments before installation.

Common Mistakes to Avoid

Avoid these missteps that can undermine laminate performance when considering underlayment options.

• Using roofing felt as a long-term underlayment: It is generally not designed for indoor flooring and may lead to moisture retention or insufficient vapor control.
• Overlooking climate considerations: Regions with high humidity or basements require specific underlayments with reliable vapor barriers.
• Ignoring warranty requirements: Using an unapproved underlayment can void the laminate warranty and expose homeowners to potential repair costs.
• Neglecting door and trim alignment: Inadequate underlayment thickness can affect doors, thresholds, and baseboard placement.

Conclusion Without Conclusion

While roofing felt has historical uses in construction, it is generally not suitable as a long-term underlayment for laminate flooring in modern U.S. homes. The preferred approach is to use underlayments specifically designed for laminate, chosen based on the product’s requirements, climate, and subfloor type. By selecting an appropriate underlayment and following the manufacturer’s installation guidelines, homeowners can achieve a durable, quiet, and moisture-controlled laminate floor installation.