How to Install a Metal Roof Over Shingles: A StepbyStep Guide for Longlasting Weatherproofing

How to Install a Metal Roof Over Shingles?

To install a metal roof over shingles, it is important to first ensure that local building department regulations allow for this type of installation.

Checking with the building department will help determine if there are any specific requirements or restrictions in place.

Additionally, the existing shingled roof should be in good shape without leaks or damage.

The slope and shape of the current roof should be assessed to ensure a smooth and even surface for the metal roof installation.

If the shingles were installed over another roof, or if they are too bulky or thick, it is recommended to remove them or apply an approved underlayment before installing the metal roof.

The installation should follow manufacturer specifications and warranty, and fasteners should be applied as instructed, with screws being preferred over nails.

Proper ventilation is crucial to prevent trapped water vapor, which can lead to rot and mold.

Venting the metal roof or using furring strips to create airflow are recommended solutions.

While metal roofs do have advantages such as longevity, resistance to fire and hail damage, and energy efficiency, it is important to address any existing leaks and replace damaged rafters or sheeting before installation.

Taking safety measures during the installation process is also important.

It is recommended to consult with professionals, such as Legacy Service, who have experience in installing metal roofs and can offer custom-made panels and a lifetime warranty.

Key Points:

  • Check local building department regulations and requirements for installing a metal roof over shingles.
  • Ensure the existing shingled roof is in good shape and free from leaks or damage.
  • Assess the slope and shape of the current roof for a smooth and even surface for the metal roof installation.
  • Remove shingles or apply an approved underlayment if necessary.
  • Follow manufacturer specifications and use screws instead of nails for fastening.
  • Provide proper ventilation to prevent water vapor build-up and consider consulting professionals for installation and custom-made panels.


Did You Know?

1. In the United States, metal roofs are experiencing a resurgence in popularity due to their durability and energy efficiency.
2. Historically, metal roofing can be traced back to ancient Rome, where copper was used to cover important structures such as the Pantheon.
3. Did you know that installing a metal roof over shingles can actually help to reduce the heat entering your home by reflecting sunlight? This can result in lower energy costs for cooling your home during hot summer months.
4. Metal roofs are also highly resistant to fire, making them an excellent choice for areas prone to wildfires.
5. An interesting fact about metal roofs is that they can often last two to three times longer than traditional asphalt shingles, averaging a lifespan of 50-70 years.

Checking Local Building Department Regulations

Before installing a metal roof over shingles, it is crucial to check with your local building department to ensure compliance with regulations. Different areas have specific requirements, and failing to adhere to them can lead to legal issues and potential problems down the line.

Related Post:  Foot: Calculating Roofing Materials for Your Home Renovation

In most cases, metal roof installation over shingles is allowed. Section 1511.3.1 of the 2018 International Building Code permits the installation of metal roofing over existing shingles. However, it’s always important to verify this information with your local authorities, as some areas may have additional regulations or restrictions.

By familiarizing yourself with the local building department requirements, you can ensure that your metal roof installation is compliant and safe. It is important to note that failure to follow these regulations could result in fines, delays, or even having to remove and reinstall the roof.

Advantages Of Metal Roofs

Metal roofs offer numerous advantages that make them an excellent option for any building, including homes. These advantages include their durability, ability to withstand various weather conditions, resistance to fire and hail damage, and the availability of a wide variety of colors.

One of the most significant advantages of metal roofs is their longevity. While traditional shingle roofs typically last for 20-30 years, metal roofs have a lifespan of 40-70 years. This extended lifespan not only saves homeowners money in the long run but also reduces the need for frequent replacements.

In addition to durability, metal roofs can also have the appearance of natural materials such as cedar shakes or stone. This allows homeowners to achieve a desired aesthetic without sacrificing the benefits of metal roofing. Furthermore, metal roofs can improve energy efficiency by reflecting solar radiant heat, potentially reducing cooling costs by 10-25%.

Another advantage of installing metal roofing over shingles is the ability to save on labor costs and prevent shingles from ending up in landfills. Instead of completely removing the existing shingles, metal roofs can be installed directly over them, reducing both cost and environmental impact.

Considerations Before Installation

Before installing a metal roof over shingles, there are several important factors to consider. Addressing any existing leaks, roof damage, or structural issues is necessary before proceeding with the installation. This may involve repairing damaged rafters or sheeting and ensuring that the existing shingled roof is in good shape.

It is also essential to follow the manufacturer’s specifications and warranty guidelines to ensure proper installation and maintain the validity of any potential warranty claims. This includes using the recommended fasteners, with screws often being preferable to nails, and paying attention to trim for both appearance and protection against the elements.

Additionally, it is crucial to prioritize safety during the installation process. This involves taking appropriate safety measures, such as using proper safety equipment and following established safety protocols. Installing a metal roof requires working at heights, so precautions should be taken to avoid accidents and ensure the well-being of everyone involved.

Proper Installation Techniques

When installing a metal roof over shingles, following proper installation techniques is key to ensure a long-lasting and weatherproof result. The metal roof must be laid flat on a vapor barrier to prevent condensation. Proper ventilation is also crucial to prevent trapped water vapor, which can lead to rot and mold.

While some homeowners choose to install the metal panels directly over the existing shingles, it is recommended to either remove the shingles or apply an approved underlayment before installation. This provides a smoother and more even plane for the metal roof and enhances its overall performance and longevity.

Another installation technique is to install 1×4 purlins over the shingles as a more expensive but higher-quality method. Purlins create a solid base for the metal roof, offering added stability and improved insulation. This option may be preferred in areas with extreme weather conditions or for those looking for the utmost quality and durability in their metal roof installation.

Related Post:  How to Make Ridge Cap With Architectural Shingles: StepbyStep Guide

Addressing Existing Issues

Before installing a metal roof over shingles, it is crucial to address any existing issues with the roof. This includes checking for leaks, damaged shingles, or compromised structural components. Failure to address these issues can lead to further problems down the line and potentially compromise the integrity of the metal roof.

If there are leaks or damage present, it is essential to repair them before proceeding with the installation. This may involve replacing damaged rafters or sheeting, as well as addressing any issues with flashing or other critical components.

Taking the time to properly address existing issues ensures a solid foundation for the metal roof and maximizes its potential lifespan and performance. It is always recommended to consult with a professional roofing contractor if you are unsure about the condition of your current roof or the necessary repairs.

  • Address any existing issues with the roof before installing a metal roof over shingles.
  • Check for leaks, damaged shingles, or compromised structural components.
  • Repair any leaks or damage present before proceeding with the installation.
  • Consider replacing damaged rafters or sheeting if necessary.
  • Consult with a professional roofing contractor if unsure about the condition of your current roof or the necessary repairs.

“Taking the time to properly address existing issues ensures a solid foundation for the metal roof and maximizes its potential lifespan and performance.”

Ventilation And Airflow Considerations

Proper ventilation and airflow are crucial considerations when installing a metal roof over shingles. Without sufficient airflow, moisture can become trapped, leading to problems such as rot and mold. Venting the metal roof or using furring strips to create airflow are recommended solutions.

Venting the metal roof involves creating openings or using vents that allow air to circulate under the metal panels. This helps to remove any trapped moisture and maintain an optimal environment. Furring strips, on the other hand, are wooden or metal strips that create a small gap between the metal roof and the shingles, allowing for airflow.

Both methods help prevent moisture buildup and ensure the long-term durability and performance of the metal roof. Proper ventilation is especially crucial in areas with high humidity or significant temperature fluctuations.

In conclusion, installing a metal roof over shingles offers numerous advantages, including durability, energy efficiency, and an extended lifespan. However, it is crucial to check local building department regulations and follow proper installation techniques. Addressing existing issues and ensuring proper ventilation are also important considerations. By carefully considering these factors and following manufacturer guidelines, homeowners can enjoy a long-lasting, weatherproof metal roof that provides both aesthetic appeal and peace of mind.

Related Post:  What Is Sheathing on a Roof and Why is it Important in Construction?

Frequently Asked Questions

Can I install metal roofing directly over shingles?

While it is technically possible to install metal roofing directly over shingles, it is generally not recommended. The constant expansion and contraction of the shingles can lead to long-term damage beneath the metal roof. To ensure the longevity and integrity of the metal roof, it is advised to remove the shingles before installation. This will provide a smoother and more stable surface for the metal roofing, reducing the risk of potential issues in the future.

What is the best way to put a metal roof over a shingle roof?

One effective method for installing a metal roof over a shingle roof is by following a specific process. Firstly, it is crucial to remove any damaged or loose shingles and repair the roof’s underlying structure as needed. Next, a synthetic underlayment should be applied on top of the shingle roof to provide a protective barrier against potential damage caused by metal expansion and contraction. This underlayment acts as a buffer that prevents the metal roof from directly contacting the shingles. By implementing this approach, the metal roof can be securely installed while minimizing the risk of long-term damage and ensuring its durability over time.

Additionally, it is essential to carefully place the metal roofing panels over the underlayment, ensuring a proper overlap and fastening the panels securely. Adhering to manufacturer guidelines and industry best practices is crucial to ensure a successful installation. Regular maintenance and inspection of the metal roof further enhance its longevity, providing a reliable and aesthetically pleasing roofing solution for years to come.

What is the problem with installing a metal roof over shingles?

One of the main problems with installing a metal roof over shingles is the difficulty in tracking and repairing future leaks. Even for professionals, identifying the source of a leak can be challenging. However, with a metal roof installed over shingles, this task becomes even harder. If water manages to seep under the metal panels, it can then travel down the old asphalt roof, finding its way into your home. This makes it more complicated to locate and fix the origin of the leak, potentially leading to further damage and inconvenience.

Do you need underlayment for metal roof over shingles?

Having underlayment for a metal roof over shingles is highly beneficial, especially in areas prone to thunderstorms or snow. The underlayment serves as a waterproofing layer, preventing any potential issues that may arise from installing metal roofing over wet shingles. Additionally, it adds an extra layer of protection against the elements, ensuring the longevity and durability of the roof.

References: 1, 2, 3, 4