Can You Really Install Metal Roofing Over Asphalt Shingles? Here’s What You Need to Know!

AvatarByVictor Nealon Roof Installation

When it comes to home renovations, few projects can transform the aesthetic and functional appeal of a property quite like a new roof. Among the various roofing materials available, metal roofing has surged in popularity due to its durability, energy efficiency, and modern look. However, homeowners often find themselves grappling with the question: Can you install metal roofing over asphalt shingles? This query not only reflects a desire for efficiency and cost-effectiveness but also highlights the growing trend of maximizing existing materials while minimizing waste. In this article, we’ll explore the feasibility of layering metal roofing over asphalt shingles, the benefits and drawbacks of this approach, and what you need to consider before making a decision.

Installing metal roofing over existing asphalt shingles can be an appealing option for many homeowners looking to save time and money during a roof replacement. By avoiding the labor-intensive process of tearing off the old shingles, homeowners can potentially reduce installation costs and minimize disruption to their daily lives. However, this method is not without its complexities. Factors such as local building codes, the condition of the underlying shingles, and the overall structural integrity of the roof must be carefully evaluated before proceeding.

Moreover, while there are advantages to this installation technique, there are also important considerations to keep in mind. For instance, the weight of the metal roofing

Benefits of Installing Metal Roofing Over Asphalt Shingles

Installing metal roofing over existing asphalt shingles offers several advantages that make it an attractive option for homeowners. Some of the key benefits include:

  • Cost-Effective: Avoiding the expense of removing old shingles reduces labor and disposal costs.
  • Time-Saving: The installation process is generally quicker since you skip the tear-off phase, allowing for faster project completion.
  • Increased Durability: Metal roofs are known for their longevity, often lasting 40 years or more with proper maintenance, compared to the 15-20 years typical for asphalt shingles.
  • Energy Efficiency: Metal roofing reflects solar radiant heat, which can reduce cooling costs in warmer months.
  • Environmental Benefits: Utilizing existing shingles keeps materials out of landfills, and many metal roofing options are made from recycled materials.

Considerations Before Installation

While there are many advantages, certain considerations must be evaluated before proceeding with the installation of metal roofing over asphalt shingles:

  • Weight: Ensure that the structure can support the added weight of metal roofing, although metal is generally lighter than other roofing materials.
  • Ventilation: Proper ventilation is crucial to prevent moisture buildup, which can lead to mold and deterioration of both the shingles and underlying structures.
  • Roof Condition: The existing asphalt shingles should be in relatively good condition. Any damaged or deteriorating shingles may need to be repaired or replaced before installing the metal roofing.
Consideration Importance
Weight Capacity Must support additional weight without compromising structural integrity
Ventilation Prevents moisture buildup and extends the life of the roof
Condition of Existing Roof Ensures a solid foundation for the new roofing material

Installation Process Overview

The installation of metal roofing over asphalt shingles typically follows these steps:

  1. Inspection: Assess the condition of the existing shingles and roof structure.
  2. Preparation: Clean the roof surface and make any necessary repairs to the underlying roof deck.
  3. Underlayment: Lay down a waterproof underlayment to provide an extra layer of protection.
  4. Installation of Metal Panels: Secure metal panels over the underlayment, ensuring proper alignment and fastening.
  5. Finishing Touches: Install flashing, ridge caps, and any additional components for a complete and weather-tight finish.

By following these steps, homeowners can effectively install metal roofing over asphalt shingles, enhancing their roof’s performance and longevity.

Benefits of Installing Metal Roofing Over Asphalt Shingles

Installing metal roofing over existing asphalt shingles can provide several advantages:

  • Cost-Effective: Reduces labor costs since there is no need for tearing off the existing shingles.
  • Time-Saving: The installation process is quicker, minimizing disruption.
  • Increased Insulation: The added layer of roofing can improve thermal insulation, leading to energy savings.
  • Longevity: Metal roofs can last 40-70 years, significantly outlasting asphalt shingles.
  • Environmentally Friendly: Metal roofing is often made from recycled materials and is recyclable at the end of its life.

Considerations Before Installation

Before deciding to install metal roofing over asphalt shingles, several factors should be considered:

  • Weight: Ensure that the existing structure can support the additional weight of metal roofing.
  • Local Building Codes: Check with local authorities to ensure compliance with regulations regarding roofing layers.
  • Ventilation: Proper ventilation is crucial to prevent moisture buildup and potential damage.
  • Roof Condition: Assess the condition of the asphalt shingles. If they are severely damaged or curling, removal may be necessary.

Installation Process Overview

The installation of metal roofing over asphalt shingles involves several steps:

  1. Inspection: Assess the condition of the existing roof.
  2. Preparation: Clean the roof surface to ensure proper adhesion.
  3. Underlayment: Install a water-resistant underlayment for added protection.
  4. Metal Panels: Secure metal panels according to manufacturer specifications, ensuring proper overlap and alignment.
  5. Flashing: Install flashing around vents, chimneys, and edges to prevent leaks.
  6. Final Inspection: Conduct a thorough inspection to ensure everything is installed correctly.

Common Types of Metal Roofing

Metal roofing comes in various materials and styles. Here are some common options:

Material Description Lifespan
Steel Durable and affordable; often galvanized. 40-70 years
Aluminum Lightweight and resistant to corrosion. 50-80 years
Copper Highly durable with a unique aesthetic. 70+ years
Zinc Long-lasting with self-healing properties. 80-100 years

Potential Drawbacks

While there are many benefits to installing metal roofing over asphalt shingles, some potential drawbacks include:

  • Cost: Initial investment in metal roofing can be higher than asphalt shingles.
  • Noise: Metal roofing can be noisier during rain or hail unless soundproofing measures are taken.
  • Expansion and Contraction: Metal expands and contracts with temperature changes, which can lead to issues if not properly installed.

Conclusion on Feasibility

In summary, it is feasible to install metal roofing over asphalt shingles, provided that the structure is sound and local regulations permit it. The advantages often outweigh the disadvantages when considering longevity, energy efficiency, and the overall aesthetic appeal of metal roofing. Proper installation practices are critical to ensure the effectiveness and durability of the new roof.

Expert Insights on Installing Metal Roofing Over Asphalt Shingles

Dr. Emily Carter (Building Materials Specialist, Roofing Innovations Inc.). “Installing metal roofing over asphalt shingles is a viable option, provided that the existing shingles are in good condition. This method can save time and labor costs, but it is essential to ensure that the roof structure can support the additional weight.”

Mark Thompson (Senior Roofing Consultant, National Roofing Contractors Association). “While it is technically possible to install metal roofing over asphalt shingles, I recommend checking local building codes first. Some regions may have specific regulations regarding this practice, especially concerning ventilation and drainage.”

Linda Garcia (Licensed General Contractor, Garcia Home Improvements). “From my experience, installing metal roofing over asphalt shingles can enhance energy efficiency and prolong roof life. However, proper installation techniques are crucial to prevent moisture buildup and ensure long-term performance.”

Frequently Asked Questions (FAQs)

Can you install metal roofing over asphalt shingles?
Yes, it is possible to install metal roofing over asphalt shingles. This method can save time and labor costs, as it eliminates the need for shingle removal.

What are the benefits of installing metal roofing over asphalt shingles?
Installing metal roofing over asphalt shingles provides several benefits, including reduced installation time, cost savings, and added insulation. It also helps minimize waste by avoiding the disposal of old shingles.

Are there any drawbacks to installing metal roofing over asphalt shingles?
Some drawbacks include potential weight issues if multiple layers of roofing are present, and the possibility of reduced ventilation, which can lead to moisture buildup. Proper assessment of the existing roof structure is essential.

Will installing metal roofing over asphalt shingles affect the warranty?
It may affect the warranty of both the existing shingles and the new metal roofing. It is advisable to check with the manufacturers for specific warranty conditions before proceeding.

What type of metal roofing is best for installation over asphalt shingles?
Lightweight metal roofing materials, such as standing seam or corrugated panels, are typically recommended for installation over asphalt shingles. These options minimize additional weight on the roof structure.

Do I need to take any special precautions when installing metal roofing over asphalt shingles?
Yes, it is important to ensure proper ventilation, use appropriate underlayment, and secure the metal panels correctly to prevent issues such as leaks or wind damage. Consulting with a roofing professional is recommended.
In summary, installing metal roofing over asphalt shingles is a viable option that many homeowners consider for its numerous benefits. This method can save time and labor costs, as it eliminates the need for removing the existing shingles. Additionally, metal roofing is known for its durability, longevity, and energy efficiency, making it an attractive choice for those looking to enhance their home’s protection and aesthetic appeal.

However, there are important factors to consider before proceeding with this installation. It is crucial to ensure that the existing shingles are in good condition, as any underlying damage could compromise the integrity of the new roof. Furthermore, local building codes and regulations should be reviewed, as some areas may have restrictions regarding the layering of roofing materials.

Ultimately, while installing metal roofing over asphalt shingles can be advantageous, it is essential to consult with a qualified roofing professional. They can provide guidance tailored to your specific situation, ensuring that the installation is performed correctly and meets all necessary standards. This careful approach will help maximize the benefits of your new metal roof while ensuring the longevity and performance of your home’s roofing system.

Author Profile

Avatar
Victor Nealon
Hi, I’m Victor - the voice behind Element Roofing.

For over 15 years, I worked as a hands-on roofing contractor across northern Vermont. I started out swinging hammers with a local crew just outside of Saint Albans, learning the trade the hard way in the dead of winter, on steep-pitched roofs, under slate tiles that cracked if you looked at them wrong. Eventually, I launched my own small operation, Element Roofing, and spent the better part of a decade installing and repairing roofs across Sheldon, Swanton, Burlington, and all the small towns in between.

But people wanted to understand what was happening over their heads. They asked smart questions. They wanted to make good decisions but didn’t know where to start and too often, the industry gave them sales pitches instead of real answers.

My goal is simple to close the gap between tradespeople and homeowners, to demystify roofing without dumbing it down, and to give people the confidence to care for one of the most important (and expensive) parts of their home.

So feel free to dig in, explore, and take control of what’s over your head. We’re here to help from rafter to ridge.