putting metal roof over asphalt shingles

Putting Metal Roof Over Asphalt Shingles A Comprehensive Guide

In recent years, homeowners have increasingly turned to metal roofing as a popular alternative to traditional asphalt shingles. One of the more convenient methods of installation is placing metal roofing directly over existing asphalt shingles. This approach not only saves time and labor costs but also offers several advantages. Here’s a detailed look at the process, benefits, and considerations of putting a metal roof over asphalt shingles.

Benefits of Metal Roofing

1. Longevity and Durability Metal roofs are renowned for their longevity, often lasting 40 to 70 years compared to asphalt shingles, which typically last 15 to 30 years. This durability makes metal roofing a solid investment for homeowners.

2. Energy Efficiency Metal roofing reflects solar radiant heat, which can reduce cooling costs by up to 25%. This is particularly advantageous in warmer climates. Moreover, many metal roofing products are now available with high reflectivity and emissivity ratings, enhancing energy efficiency further.

3. Environmentally Friendly Metal roofs are 100% recyclable at the end of their life cycle, making them an eco-friendly choice. In contrast, asphalt shingles can contribute significantly to landfill waste.

4. Reduced Installation Time and Labor Costs By installing a metal roof over existing shingles, you can avoid the time-consuming process of tearing off the old roof. This not only lowers labor costs but also minimizes disruption to your household.

5. Improved Aesthetics Metal roofing comes in a variety of styles and colors, allowing homeowners to choose an appealing appearance that complements their home’s architecture.

Installation Process

The process of installing a metal roof over asphalt shingles is straightforward, but it’s essential to follow proper steps to ensure a successful installation.

1. Inspection Before installation, check the existing shingles for any damage, such as cracked or missing pieces. Address any structural issues, as the metal roof will need a solid foundation.

2. Preparation Clean the roof surface to remove any debris, such as leaves or dirt. Ensure any loose asphalt shingles are secured down.

3. Install a Membrane It is advisable to install a breathable underlayment over the shingles. This acts as a moisture barrier and helps protect against condensation. Additionally, it provides an extra layer of insulation.

4. Installing Furring Strips Some installations may require furring strips (1x4 or 1x6 lumber) to provide a solid foundation for the metal panels. These strips create a gap that allows for airflow, reducing the chances of moisture buildup and enhancing the roof’s durability.

5. Positioning the Metal Panels Begin at the lower edge of the roof and work upwards. Align the metal panels securely, ensuring they overlap appropriately to prevent water infiltration. Use screws specifically designed for metal roofs to fasten each panel, ensuring a tight seal.

6. Finishing Touches Install ridge caps and any other necessary accessories to complete the installation and provide additional protection against the elements.

Considerations

While installing metal roofing over asphalt shingles offers many benefits, there are some factors to keep in mind

- Weight Although most metal roofs are lightweight compared to other roofing materials, it's crucial to ensure that the underlying structure can support the added weight.

- Local Building Codes Check local building regulations before proceeding, as some areas may have restrictions on roofing materials and installation techniques.

- Aesthetic Changes While metal roofs can enhance a home’s appearance, the texture and height difference of layers may affect the visual appeal. Ensure you select panels that fit well with your home’s style.

- Potential for Moisture Buildup If not installed correctly, moisture could become trapped between the layers, leading to potential damage. Proper ventilation and installation techniques can mitigate this risk.

Conclusion

Putting a metal roof over asphalt shingles can be an efficient and cost-effective roofing solution that delivers impressive long-term benefits. By understanding the installation process and considering essential factors, homeowners can confidently embark on this project, enhancing their home’s value and aesthetic appeal while enjoying the practical advantages of metal roofing. If you’re considering this upgrade, consulting with a roofing professional can ensure a seamless transition to your new roofing system.