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Is Installing A Metal Roof Over Shingles A Smart Move Or A Recipe For Disaster?

Posted on August 19, 2023

Estimated Reading Time : 6 Min.

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Is Installing A Metal Roof Over Shingles A Smart Move Or A Recipe For Disaster?

Are you a homeowner in Wisconsin wondering if you can install a metal roof over your existing shingles? As experienced roofers, we have encountered this common question time and time again.

While you definitely can install a metal roof over shingles, whether you should be putting a metal roof over shingles is another question. 

However, our team of professional roofing contractors at BRH Enterprises has put together this guide to help you understand the pros and cons of installing a metal roof over shingles so you can make an informed choice for your home. 

Let’s dive in!

The Appeal of Installing a Metal Roof Over Shingles 

Metal Roof Over Shingles

Have you ever wondered about the pros and cons of installing a metal roof over shingles? In the next section, we will examine both in detail.

The Benefits of Installing a Metal Roof Over Shingles

1. Cost Savings and Time Efficiency

The potential cost savings of installing a metal roof over shingles is significant. By leaving the existing shingles in place, you could save a substantial amount on labor and disposal costs. Plus, it makes the installation process quicker, which can save you money on labor and materials. 

2. Additional Insulation and Energy Efficiency

On their own, metal roofs have great insulation properties and when you opt to install a metal roof over shingles, you’re effectively adding an extra layer of insulation to your home. This additional insulation serves to stabilize your indoor temperatures, allowing you to consume less energy, which in turn, noticeably lowers your utility bills. 

3. Enhanced Durability and Longevity

The durability and longevity of metal roofs are nothing short of remarkable. By simply installing a metal roof over your existing shingles, you could significantly extend the life of your entire roofing system. With the right care, a metal roof can stand strong for a whopping 50 years or more, offering enduring value for your investment. 

4. Environmental Benefits

By choosing a metal roof, you’re not just selecting a sturdy cover for your home, you’re also making a significant contribution to sustainable practices, as most metal roofs can be recycled at the end of their lifespan, or are made from previously recycled materials. Plus, by installing a metal roof over shingles, you are limiting the excess waste that would have ended up in the landfill. 

Considerations and Potential Drawbacks

While there are clear benefits to installing a metal roof over shingles, it is essential to be aware of the potential drawbacks.

1. Hidden Roof Deck Issues

One major obstacle that often goes unnoticed when installing a new roof over the old one is the difficulty in conducting a thorough inspection of the roof deck. 

The roof deck is the unsung hero of your roofing system – it’s the foundation that holds everything together. But, it has its vulnerabilities, such as susceptibility to rot or damage. 

These hidden issues could undermine your roof’s structural integrity, leaving you with major, expensive problems. And without removing the shingles, spotting these problems can be incredibly difficult.

2. Difficulty in Locating and Repairing Leaks

With two layers of roofing materials, finding the source of a leak can be near impossible. The water slips between the layers, making it a real challenge to trace its origin. This tricky situation not only delays your repair efforts but also inflates the overall cost. 

3. Continued Aging of the Underlying Shingles

When you decide to install a metal roof over an existing material, it doesn’t mean you can just forget about the shingles underneath. They will continue to deteriorate, even under the sturdy metal. Potential problems and maintenance needs could crop up over time for the shingles and will be hard to remedy. If you don’t remove the old shingles, you might overlook existing issues and miss the chance to start fresh.

4. Additional Weight Considerations

Have you ever considered the weight-bearing capacity of your roof before deciding to install a metal roof over shingles? It’s a crucial factor that often goes unnoticed. 

Yes, metal roofs are generally lightweight, but the cumulative weight of the new metal roof coupled with your existing shingles can add substantial stress to your roofing structure. 

For those with older homes, it might be necessary to reinforce the roof’s structure in order to help it bear the additional weight. It’s not just about the aesthetic appeal, but also the structural integrity of your home. 

Ensuring a Successful Metal Roof Installation Over Shingles

If you decide that installing a metal roof over shingles is the right choice for your home, there are essential steps to follow to ensure a successful installation:

1. Consult Local Building Codes and Regulations

Before embarking on your roofing project, make sure you have checked with your local building authority. Some regions have specific guidelines when it comes to roof overlays. Sticking to these regulations isn’t just about staying on the right side of the law, but also about ensuring the safety of everyone within the home. 

In Wisconsin, it is possible to install a metal roof over asphalt shingles, but not over other materials including wood shake, slate, clay, or cement tiles. There are also some regulations regarding the state of the existing shingles, so make sure to consult with a local roofing company to ensure compliance.

2. Assess the Condition of the Existing Shingles

Before you jump into this installation project, it’s crucial to take a good, hard look at the current state of your shingles. 

Are they in tip-top shape? Free from any telltale signs of damage, rot, or deterioration? If you answered no to any of these questions, you should not install a metal roof over the shingles. Your new roof needs a solid foundation, and faulty or aging materials will just lead to more problems later on.

Any necessary repairs or replacements should be addressed before you proceed with the installation. Think of it this way, you wouldn’t build a house on an unstable foundation. The same principle applies here. Ensuring that your shingles are in great condition is not just a recommendation – it’s a necessity. 

3. Choose the Right Metal Roofing System

Metal Roofing Over Shingles

Choosing the right metal roofing system to install over your existing shingles can feel like navigating a maze. The key lies in considering a few essential factors:

  • The desired aesthetics of your property
  • The weight of the material and the strength of your roof deck 
  • Warranty specifications of both the shingles and the new metal roof

But remember, you don’t have to do this alone. A reputable roofing contractor can be your compass, guiding you to the metal roofing system that fits your unique needs and integrates seamlessly with your existing shingles.

4. Proper Preparation and Installation Techniques

Installing a new roof over shingles begins with meticulous preparation and a contractor who’s committed to excellence when it comes to installation techniques. Before you dive into this project, your existing shingles should get a deep clean and a thorough inspection. 

When installing your metal roof, you’ll need to do more than just follow industry best practices. You’ll also need to heed the guidelines and recommendations provided by the manufacturer. This might seem like a lot to ask, but trust me, it’s the secret to a successful installation. 

5. Regular Maintenance and Inspections

Remember, the journey doesn’t end just because your new metal roof was installed. To guarantee the longevity and high performance of your new roof, regular maintenance and inspections are non-negotiable. 

Think of it as a regular health check-up for your roof. It’s always easier to fix small issues before they snowball into bigger problems.

Schedule periodic inspections with your local roofing contractor. Look out for any signs of damage, leaks, or troubles with the underlying shingles. Spotting these early on can save you a lot of stress and money down the line. And if you do find any issues, take care of them as soon as possible. 

Promptly addressing necessary repairs not only prevents further damage but also extends the lifespan of your beautiful metal roof.

Final Thoughts On Installing Metal Roofing Over Shingles

Installing Metal Roofing Over Shingles

So, is installing a metal roof over your existing shingles a smart move or a potential disaster waiting to happen? 

The answer varies, but it can be a very practical choice for those seeking to save on expenses while improving energy efficiency and durability. 

However, like all significant home improvement projects, it’s crucial to carefully weigh the pros and cons, considering the unique circumstances of your roof. 

Before making such a major decision, why not consult with a professional metal roofing contractor

BRH Enterprises is always available to homeowners in Mayville, and the surrounding areas of Wisconsin, to provide expert advice and services for all your roofing needs, including metal roofing over shingles. We believe in empowering our clients with information that will help them to make the smartest choices for their homes.

Call us today at (920) 249-4228!

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