Roofing felt is traditionally used as a protective layer under shingles for roofs, but it also serves as a practical underlayment option for flooring projects. When used as floor underlayment, roofing felt offers moisture resistance, cushioning, and a barrier against dust and debris. This article explores the advantages of using roofing felt for floor underlayment, its types, installation methods, and how it compares to other flooring underlayment materials.
| Aspect | Description |
|---|---|
| Purpose | Moisture barrier, cushioning, and protection under flooring |
| Material Types | Organic felt, fiberglass-reinforced felt |
| Common Uses | Under hardwood, laminate, engineered wood, and some tile floors |
| Benefits | Water resistance, sound dampening, affordability |
| Installation Tips | Ensure clean surface, overlap seams, secure properly |
What is Roofing Felt and Why Use It as Floor Underlayment?
Roofing felt is a heavy-duty protective fabric saturated with asphalt or bitumen, designed to protect roofs from moisture and environmental damage. When repurposed as floor underlayment, it serves multiple functions, including moisture resistance, cushioning between the subfloor and the finished flooring, and reducing wear and tear on flooring materials.
For flooring applications, roofing felt offers a low-cost and effective alternative to specialized floor underlayments. Its moisture barrier properties are especially valuable in areas prone to humidity or occasional water exposure. Additionally, roofing felt provides some sound insulation, helping to soften footsteps and decrease sound transmission.
Types of Roofing Felt Suitable for Floor Underlayment
Roofing felt comes in several grades and compositions, making it important to choose the right type for floor underlayment:
- Organic Roofing Felt: Made from natural fibers like wood pulp or rag, saturated in asphalt. It provides excellent moisture resistance and is more flexible but may absorb more moisture over time.
- Fiberglass-Reinforced Felt: Combines fiberglass mats with asphalt saturation for added strength and durability. It is more resistant to tearing and less likely to absorb moisture but is stiffer and can be more difficult to handle.
For floor underlayment, fiberglass-reinforced felt is typically preferred due to its durability and moisture resistance. However, organic felt remains a popular choice for many residential flooring projects due to its ease of installation and affordability.
Key Benefits of Using Roofing Felt for Floor Underlayment
Using roofing felt as a floor underlayment offers various advantages that benefit both the installation process and the longevity of the floor:
- Moisture Barrier: Roofing felt creates a protective layer that reduces moisture migration from the subfloor, which is critical for hardwood, laminate, or engineered wood flooring.
- Cushioning Effect: It provides a minor cushioning effect, reducing floor squeaks and making walking on the floor more comfortable.
- Sound Dampening: Helps to decrease noise transmission between floors, enhancing the acoustic comfort of indoor spaces.
- Cost-Effective: Roofing felt tends to cost less than specialized foam or rubber floor underlayments while still offering essential protective features.
- Easy Installation: Lightweight and flexible, it can be quickly rolled out and cut to fit, speeding up the preparation phase of flooring projects.
How Roofing Felt Compares to Other Floor Underlayment Materials
| Underlayment Type | Moisture Resistance | Sound Dampening | Cushioning | Cost | Typical Use Case |
|---|---|---|---|---|---|
| Roofing Felt | Good | Moderate | Moderate | Low | Basic moisture protection under hardwood, laminate |
| Foam Underlayment | Good | High | High | Medium | Laminates, engineered floors, noise-sensitive areas |
| Cork Underlayment | Good | High | Moderate | High | Eco-friendly, sound reduction, thermal insulation |
| Rubber Underlayment | Excellent | Excellent | High | High | Hard floors requiring heavy soundproofing |
Roofing felt offers reasonable protection and performance at a lower cost than many specialty flooring underlayments. However, for floors requiring advanced soundproofing or cushioning, foam or rubber underlayments may be more suitable.
Installation Guidelines for Roofing Felt Floor Underlayment
Proper installation of roofing felt as a floor underlayment is critical to maximize its moisture barrier and cushioning properties. Follow these step-by-step guidelines for an effective setup:
- Prepare the Subfloor: Ensure the subfloor is clean, dry, and free of debris or nails that could puncture the felt.
- Measure and Cut: Roll out the roofing felt and cut it to fit the flooring area, allowing slight overlaps (typically 2-4 inches) at seams to maintain continuous protection.
- Apply Adhesive if Needed: For installations over plywood or concrete, applying a floor-appropriate adhesive under the felt can help prevent shifting.
- Secure the Felt: Use staples or roofing nails with wide heads (for wood subfloors) to attach the felt, taking care not to create punctures that could lead to moisture intrusion.
- Seal Seams: Overlapped seams should be sealed with waterproof tape designed for roofing or flooring applications to enhance moisture protection.
- Install Flooring: Once the felt is securely installed and seams sealed, proceed with installing hardwood, laminate, or other flooring materials as usual.
It is essential to avoid walking on the roofing felt excessively before the flooring is installed to prevent tearing or displacement of the underlayment.
Best Practices and Considerations
- Climate Considerations: In environments with high humidity or moisture concerns, roofing felt can be a cost-effective moisture barrier but might be supplemented with vapor barriers for enhanced protection.
- Compatibility with Flooring Types: Roofing felt is best suited for hardwood, engineered wood, and laminate floors. It is not recommended for use under vinyl or carpet flooring, which require different underlayments.
- Environmental Impact: Some roofing felts contain asphalt or bitumen, which are petroleum-based. For eco-conscious projects, consider recycled or alternative underlayments.
- Thickness Matters: Roofing felt comes in different thicknesses, usually measured in pounds per square (e.g., 15-lb or 30-lb felt). Heavier felts offer better durability but are less flexible.
- Check Building Codes: Always verify local building codes and flooring manufacturer recommendations before selecting roofing felt as an underlayment.
Common Questions About Roofing Felt as Floor Underlayment
Can Roofing Felt Be Used Under All Flooring Types?
No, roofing felt is most suitable for hardwood, laminate, and engineered wood floors. It is not ideal for vinyl, tile, or carpeted floors because those materials typically require specialized underlayments tailored to their installation and performance needs.
Is Roofing Felt Moisture-Resistant Enough for Basements?
Roofing felt provides a moderate moisture barrier. In basements or damp areas, combining it with a vapor barrier or using specialized moisture-resistant underlayments is recommended for better protection.
How Thick Should the Roofing Felt Be for Floor Use?
15-lb roofing felt is sufficient for most residential flooring underlayment. For enhanced durability or commercial applications, 30-lb felt may be used, but it can be less flexible and harder to install.
Does Roofing Felt Help Soundproof Flooring?
Roofing felt offers some sound dampening but is not specialized soundproofing underlayment. For significant noise reduction, foam or rubber underlayments perform much better.
Summary
Roofing felt is a versatile, affordable option for floor underlayment, providing essential moisture resistance and cushioning for hardwood, laminate, and engineered wood floors. While it may not offer advanced soundproofing or cushioning compared to specialized underlayments, its ease of installation and moisture protection make it an excellent choice for many flooring projects. Proper installation, seam sealing, and adherence to local codes are essential to maximizing its benefits in flooring applications.