Can I Use Roofing Felt as a House Wrap?

Using roofing felt as a house wrap is not recommended although it is technically possible. The primary function of roofing felt is to protect the roof, while a house wrap serves a dedicated role in protecting the walls and preventing moisture build-up. Here is a detailed exploration of the differences and potential issues.

Differences Between Roofing Felt and House Wrap

Material Composition

Roofing Felt: Typically made from asphalt-saturated paper or fiberglass, engineered for water resistance on roofs. This material is not specifically designed for long-term exposure to weather and UV light, making it less durable over time.

House Wrap: Usually made from synthetic materials like polyethylene or polypropylene, designed to be breathable while providing moisture resistance. These materials are engineered to withstand long-term exposure to weather.

Breathability

Hole Wrap: House wraps are specifically engineered to allow moisture vapor to escape from the wall assembly, reducing the risk of mold and rot. They provide a necessary breathability that is often lacking in roofing felt.

Roofing Felt: While roofing felt does offer some level of moisture protection, it is less breathable. This means that moisture can potentially be trapped inside the walls, leading to issues such as mold and rot.

Durability

Hole Wrap: House wraps are designed for long-term exposure to weather and UV light. They are more durable and resistant to degradation over time.

Roofing Felt: Roofing felt may degrade faster when exposed to the elements, reducing its effectiveness over time.

Potential Issues

Moisture Management: The use of roofing felt can lead to moisture issues within the wall assembly due to its lower breathability. This means that trapped moisture can cause damage to the structure of the house, leading to potential mold and mildew problems.

Code Compliance: Local building codes may specify the use of approved house wrap materials. It is important to check your local regulations before using roofing felt as a house wrap. Non-compliance can lead to additional costs and potential legal issues.

Conclusion

While roofing felt can provide some level of moisture protection, it is not ideal for use as a house wrap. For optimal performance and compliance with building standards, it is best to use a product specifically designed for house wrapping. Options such as Tyvek and other breathable synthetic wraps are recommended for their superior breathability and durability.

Historically, many houses were built with roofing felt under lap siding, and it did work effectively. However, its drawbacks—such as poor breathability and the potential for moisture retention—make it less suitable for modern building practices.

Key Takeaways:

Use a product specifically designed for house wrapping for optimal moisture protection. Check local building codes to ensure compliance. Consider the breathability and durability of your chosen material.

By choosing the right material, you can ensure the long-term protection and durability of your home. If you need to use roofing felt for temporary purposes, ensure proper sealing and consider using it in conjunction with breathable synthetic materials.