Can You Install a Metal Roof Over Shingles?

September 6, 2024
construction worker on roof

Is your roof approaching the end of its life, but the thought of tearing it off sounds messy, expensive, and time-consuming? You’re not alone. Thousands of homeowners face the same dilemma every year. With the rising cost of home repairs, finding a cost-effective, efficient solution is more important than ever. 

But what if you didn’t have to tear off your old shingles? Could installing a metal roof directly over your existing shingles be the answer? Let’s explore whether this innovative approach could save you both time and money while giving your home a long-lasting, durable roofing upgrade.

Table of Contents

Understanding Metal Roofing

When you’re considering a new roof, metal might not be the first material that comes to mind, but it’s becoming an increasingly popular choice. Why? Because metal roofing isn’t what it used to be—think corrugated steel on barns or old industrial buildings. 

Today’s metal roofs are sleek, modern, and come with a host of benefits that make them an excellent option for homeowners looking for long-term durability and energy savings.

Benefits of Metal Roofs

So, why are more and more homeowners turning to metal roofs? The benefits are hard to ignore:

  • Durability: When you opt for a metal roof, you’re investing in a material that can last 50 years or more—far outlasting the typical 15-20 year lifespan of asphalt shingles. Whether you live in an area prone to high winds, heavy snow, or extreme temperatures, metal roofs are designed to stand up to the elements.
  • Energy Efficiency: With energy costs on the rise, anything that helps lower those bills is a win. Metal roofs reflect heat from the sun rather than absorbing it, keeping your home cooler in the summer and reducing your reliance on air conditioning. Some homeowners have reported savings of up to 25% on their cooling costs after switching to a metal roof.
  • Low Maintenance:If you’re not keen on the idea of regular roof repairs or replacing shingles every few years, a metal roof could be the answer. They require very little maintenance, often needing only occasional inspections and cleanings to stay in top condition.
  • Environmental Benefits: Concerned about your carbon footprint? Metal roofs are often made from recycled materials and are fully recyclable at the end of their long life. Compare that to asphalt shingles, which often end up in landfills, and it’s easy to see why metal roofs are the greener option.

Types of Metal Roofing

There’s no one-size-fits-all approach to metal roofing, so let’s talk options:

  • Standing Seam: If you’ve seen modern, high-end homes with sleek metal roofs, you’ve probably seen standing seam roofs. These have interlocking panels that give a smooth, contemporary look while providing superior water resistance. But they don’t come cheap—they’re among the more expensive options.
  • Metal Shingles: Want the look of traditional shingles but with the benefits of metal? Metal shingles mimic the appearance of asphalt, slate, or wood but come with the added perks of durability and energy efficiency. These are perfect for homeowners who want the aesthetic of a traditional roof with a twist.
  • Corrugated Panels: This might be the metal roofing you’re most familiar with—those wavy panels commonly seen on barns or industrial buildings. While they’re affordable and strong, they might not give the polished look you’re after for a residential home.

Each option has its own pros and cons, but all types of metal roofs can potentially be installed over your existing shingles—so let’s talk about why you might want to go that route.

Why Homeowners Consider Installing Over Shingles

Home repairs can be expensive, and replacing your roof is no exception. The thought of stripping off an entire roof’s worth of shingles can be overwhelming. That’s why the option to install metal roofing over existing shingles is becoming a popular alternative for homeowners who want to save money and avoid a massive teardown.

Cost Savings

By leaving the old shingles in place, you can cut down significantly on labor and disposal fees. If you’re working with a tight budget or simply looking for a way to avoid unnecessary expenses, installing metal roofing over shingles can be a game-changer.

Time Efficiency

No one wants a major home improvement project dragging on for weeks. The time it takes to remove shingles, haul them away, and then begin installing a new roof can be substantial. By skipping the tear-off process, you cut down on the time your home is exposed to the elements and drastically reduce the overall project timeline. 

For homeowners who want to minimize disruption to their daily lives, installing a metal roof over shingles is an appealing option.

Environmental Benefits

We’re all trying to be a bit more eco-conscious these days. Did you know that every year, millions of tons of asphalt shingles end up in landfills? By installing a metal roof over your existing shingles, you’re reducing your waste contribution while also improving your home’s energy efficiency. 

Plus, since metal roofs are made from recyclable materials, you’re making an environmentally sound and sustainable choice.

Benefits of Installing a Metal Roof Over Shingles

Beyond saving money and time, there are several other reasons you may want  to opt for installing a metal roof over your existing roof with shingles. These benefits might surprise you.

Cost Savings on Tear-Off

The most obvious benefit is skipping the cost of tearing off old shingles. The labor involved in tearing off and hauling away old roofing material can get pricey fast, especially for large homes. By eliminating this step, you can pocket that money or invest it in higher-quality materials for your new metal roof.

Added Insulation and Noise Reduction

Here’s an unexpected perk: leaving the old shingles in place provides an extra layer of insulation. That’s right—your existing shingles can help keep your home warmer in the winter and cooler in the summer. 

Plus, if you are concerned that metal roofs can get noisy during rainstorms, you’ll be pleased to know that the extra layer of shingles can help reduce that noise. With two layers between you and the elements, you’ll likely hear less noise than you would with a single-layer roof.

Faster Installation Process

If you’ve ever had a home improvement project take twice as long as expected, you know how disruptive it can be. Installing a metal roof over your existing shingles speeds up the process considerably. Fewer steps mean fewer days of your home being a construction site, which is especially important if you live in a region with unpredictable weather.

Avoids the Hassle and Mess of Roof Tear-Off

Let’s face it—tearing off a roof is messy. The debris, dust, and general mess that comes with stripping off shingles can be overwhelming. By opting for an installation over your existing shingles, you avoid the mess entirely. No dumpsters sitting in your driveway, no stray nails scattered across your yard, and no headaches.

Potential Risks and Challenges

Like any major home improvement project, installing a metal roof over shingles isn’t without its challenges. Before moving forward, it’s important to weigh the risks to determine if this is the right choice for your home.

Structural Weight Concerns

While metal roofs are typically lighter than traditional roofing materials, adding a second layer of roofing means adding extra weight to your home’s structure. This can be a concern for older homes or those with structural vulnerabilities. 

If your home’s framing isn’t built to handle the additional load, you could be looking at issues like sagging or even structural failure down the line. Before you make any decisions, it’s essential to have a structural engineer or roofing expert assess whether your home can support the weight of a new metal roof over existing shingles.

Hidden Roof Damage

One of the biggest concerns with leaving old shingles in place is the possibility of hidden damage. If your current shingles are covering up rot, leaks, or other issues, installing a new roof on top won’t solve the underlying problem. 

Over time, hidden damage can worsen and lead to costly repairs inside your home, such as water damage or mold. The key is to thoroughly inspect the existing roof for any signs of damage before proceeding with a metal installation. In some cases, a partial tear-off might be necessary to address problem areas.

Warranty Issues

Another potential roadblock? Warranties. Many metal roofing manufacturers offer warranties that cover their products for decades, but those warranties often come with conditions. Some manufacturers may void the warranty if the roof is installed over existing shingles, as this can affect the integrity of the new roof. 

Be sure to check the fine print before making your decision. You’ll want to confirm that the installation method you choose won’t jeopardize your warranty protection.

Reduced Ventilation

Proper roof ventilation is crucial to maintaining a healthy roofing system. Without adequate airflow, moisture can build up under the roof, leading to mold, mildew, and even rot. Installing a metal roof over existing shingles can potentially reduce ventilation, especially if the shingles were already part of a poorly ventilated roof. 

To avoid this, many roofing professionals install furring strips between the old roof and the new metal roof, creating a ventilation gap. It’s an extra step, but one that can protect your roof from future moisture problems.

The Installation Process

If you’ve weighed the pros and cons and decided that installing a metal roof over shingles is the right choice for your home, here’s what to expect from the installation process. While faster than a traditional roof replacement, there are still several key steps involved.

Laying Down Underlayment

Before the metal panels go up, a layer of underlayment is placed over the existing shingles. This is a critical step in protecting your roof from moisture. The underlayment acts as a barrier, preventing any water that might seep through the metal panels from reaching your home’s structure. High-quality synthetic underlayments are often preferred for their durability and water resistance.

Installing Furring Strips

To avoid ventilation problems, furring strips (also known as battens) are typically installed over the underlayment. These strips create a gap between the old shingles and the new metal roof, allowing air to circulate and preventing moisture buildup. They also provide a solid surface for the metal panels to be attached to, ensuring a secure installation.

Securing Metal Roofing Panels

Once the furring strips are in place, the metal panels are installed. Proper alignment and secure fastening are crucial here to ensure the roof is watertight and durable. Depending on the type of metal roofing you’ve chosen—whether standing seam or corrugated panels—the installation process may vary slightly, but the goal is always the same: to create a roof that stands up to the elements.

Ensuring Adequate Flashing

Flashing is a crucial part of any roofing system. Installed around chimneys, vents, and skylights, flashing helps prevent leaks where the roof meets these structures. When installing a metal roof over shingles, it’s essential that the flashing is done correctly to avoid water damage and ensure a long-lasting, leak-free roof.

Cost Consideration

When it comes to roofing projects, cost is always top of mind. Installing a metal roof over existing shingles can save you money, but it’s important to understand the full cost picture before jumping in.

Cost Comparison

The biggest savings come from avoiding the tear-off process, but how much will it really save you? Labor costs for tear-offs can range from $1 to $5 per square foot, depending on your location and the complexity of the job. 

By skipping this step, you could save thousands of dollars. However, you’ll still need to factor in the cost of materials (metal roofing tends to be pricier than asphalt shingles) and any additional work needed, such as installing furring strips or repairing problem areas under the shingles.

Potential Savings

While metal roofs are more expensive upfront, they pay off in the long run. Not only will you save on energy costs thanks to metal’s reflective properties, but you’ll also avoid the frequent maintenance and replacement costs that come with asphalt shingles. In the long term, a metal roof can add value to your home and save you money.

Conclusion

Installing a metal roof over existing shingles might seem like a shortcut, but in many cases, it’s a smart, cost-effective solution. You save money on labor, avoid the mess of a tear-off, and get the durability and energy efficiency of a metal roof. 

However, it’s essential to weigh the potential risks—such as structural concerns and hidden damage—before making your final decision. With the right preparation and professional guidance, you can enjoy a long-lasting, beautiful metal roof without the hassle of starting from scratch.

FAQs

Can you put on a metal roof without removing shingles? 

Yes, in most cases, metal roofs can be installed over shingles. However, it’s important to inspect the existing roof for damage and ensure that your home’s structure can support the additional weight.

How much more expensive is a metal roof over shingles? 

While metal roofing materials are generally more expensive than shingles, the cost savings from skipping the tear-off process can offset some of the higher upfront costs.

How long does a metal roof over shingles last? 

A properly installed metal roof can last 40-70 years, depending on the materials used and the quality of the installation.

What is the biggest problem with metal roofs? 

The most common concerns with metal roofs include noise during rainstorms and the potential for denting. However, these issues can often be mitigated with proper insulation and the use of higher-quality materials.

Can installing a metal roof over shingles void my home insurance? 

It’s possible that installing a metal roof over shingles could affect your insurance coverage. It’s best to check with your insurance provider to ensure you’re still fully covered.

Does a metal roof increase home resale value? 

Yes, a metal roof can increase your home’s resale value, as many buyers see it as a durable, low-maintenance option.

Sources

Additional Roofing Resources