Making decisions about your home’s roof can feel overwhelming. After all, it’s not just about aesthetics—your roof plays a critical role in:
- Protecting your home from the elements
- Maintaining energy efficiency
- Ensuring comfort for you and your family
If you’re considering a metal roof for your home, you may have come across the seemingly convenient option of installing a metal roof directly over an existing shingle roof.
At first glance, this might seem like a cost-effective solution that saves time and effort. However, installing a metal roof over shingles comes with potential drawbacks that can lead to costly repairs in the long run. Stick with us as we guide you through the details so you can make an informed decision.
What Is a Metal Roof Over Shingles?
Before we jump into the reasons why this option might not be ideal, let’s first clarify what it actually entails. Installing a metal roof over shingles means placing metal roofing panels directly on top of your existing asphalt shingle roof without removing the old roofing material. Instead of tearing off the existing shingles, the new metal roof is typically secured using furring strips (wood battens) or a similar setup layered onto the shingles.
While this method can save time and reduce the immediate mess of removing the old roof, it’s important to weigh these benefits against the potential risks.
Why Are Metal Roofs Popular?
First, let’s talk about why so many homeowners are drawn to metal roofs. Metal roofs offer numerous advantages over traditional asphalt shingles, including:
- Durability: Metal roofs are incredibly sturdy and can last 40 to 70 years, far longer than the average 20-year lifespan of shingles.
- Energy Efficiency: Metal reflects sunlight, helping to keep your home cooler during the summer months and reducing energy costs.
- Environmentally Friendly: Many metal roofs are made from recycled materials and are 100% recyclable at the end of their life.
- Low Maintenance: Metal roofs require less maintenance compared to other types of roofing materials, such as shingles or wood shakes.
- Modern Aesthetic: Metal roofing provides a sleek, contemporary appearance that’s becoming increasingly popular with homeowners.
Given these benefits, it’s easy to see why metal roofs are gaining traction. But does this mean adding a metal roof over shingles is a good way to enjoy these perks? Not necessarily. While metal roofing can be an excellent choice, how it’s installed can make all the difference.
Why Do People Consider Installing Metal Roofing Over Shingles?
Some homeowners and contractors may advocate for placing metal roofs over existing shingles due to the following reasons:
- Time Savings: Removing old shingles is labor-intensive. Placing a metal roof over them eliminates this step, speeding up the installation process.
- Cost Savings: With fewer labor hours required to strip the old roof, you save on labor costs.
- Reduced Waste: Avoiding a complete tear-off reduces the amount of waste sent to landfills—a benefit that can appeal to eco-conscious homeowners.
- Temporary Convenience: For homeowners on a tight schedule, the faster installation timeline can seem like an attractive solution.
While these points may seem convincing at first, it’s essential to understand the risks that can outweigh these temporary conveniences.
6 Reasons Why You Should Avoid Placing a Metal Roof Over Shingles
Although the idea of installing a metal roof over shingles has its appeal, there are several key reasons why experts—including our team at McCormick Roofing—strongly recommend removing shingles before installing a metal roof.
1. Hidden Structural Issues
When you leave old shingles in place, it’s difficult to inspect the condition of your roof deck—the foundation of your roof. If there are any rotting, leaking, or weakened areas in the roof deck, they will go unnoticed underneath the new metal roof.
Over time, these hidden issues can worsen, leading to structural damage that could have been avoided with a full roof replacement.
2. Reduced Lifespan of Your Roof
Adding a metal roof over shingles can trap heat and moisture between the two layers.
This trapped moisture can lead to the growth of mold or mildew, which may weaken both the roof deck and the underside of the metal roofing panels. Consequently, the lifespan and performance of your new roof may be compromised.
3. Uneven Surface and Poor Aesthetic Finish
Shingles create an uneven surface. When you install a metal roof over them, this unevenness can transfer to the metal panels, resulting in an irregular appearance. Over time, the weight and pressure of the metal can exacerbate the unevenness, reducing the roof’s visual appeal.
4. Excessive Weight on the Roof Structure
Metal roofing is lightweight, but when combined with the weight of existing shingles, the added burden can strain your roof’s structure. This is especially concerning for older homes that may not be designed to bear additional weight. Over time, the accumulated weight can lead to sagging or structural instability.
5. Code Compliance and Warranty Issues
Check your local building codes—some areas may actually prohibit installing a metal roof over shingles due to the potential risks.
Additionally, many manufacturers’ warranties for metal roofing may not cover installations done over existing shingles. This could leave you unprotected in the event of future issues.
6. Compromised Safety
Without a proper tear-off, it’s harder to identify and address any underlying issues with ventilation and insulation. Poor ventilation can lead to excessive heat buildup in your attic or living spaces, creating potential safety and energy-efficiency concerns.
What’s the Best Option? A Full Tear-Off Installation
To ensure the long-term success of your new metal roof, a full tear-off installation is the way to go. Here’s why:
- Comprehensive Inspection: Tearing off the old shingles gives your contractor the opportunity to thoroughly inspect the roof deck for any rot, leaks, or weak spots.
- Optimal Ventilation and Insulation: With a clean slate, your contractor can properly install ventilation and insulation systems, keeping your home comfortable and energy efficient.
- Flawless Appearance: Installing metal roofing on a smooth, clean surface ensures the panels lie perfectly flat, giving your home a polished and professional look.
- Longevity: A metal roof installed directly onto the roof deck without underlying shingles offers the best probability of lasting its full lifespan, providing you with years of reliable performance.
How McCormick Roofing Can Help
At McCormick Roofing, we specialize in providing high-quality roofing solutions tailored to your home’s specific needs. If you’re considering a metal roof, we’ll ensure it’s installed the right way—without cutting corners. Here’s how we go above and beyond:
Expert Inspections 🧠
Our team conducts thorough inspections of your existing roof to identify any underlying issues before we begin the installation.
Premium Materials 🧱
We use top-grade metal roofing panels that are designed for durability, energy efficiency, and aesthetic appeal.
Professional Craftsmanship 👷🏼♂️
Every installation is carried out by our skilled professionals, ensuring precision and attention to detail.
Transparent Pricing 💵
We provide clear, upfront pricing so you know exactly what to expect—no surprises.
Commitment to Customer Satisfaction 👍
Your satisfaction is our top priority. From the initial consultation to the final inspection, we’ll work with you every step of the way to ensure your new roof is exactly what you envisioned.
The Right Roofing Contractor For You
While installing a metal roof over shingles might seem like a quick fix, it’s a decision that can lead to significant challenges down the road. For a secure, durable, and visually appealing roof—and for peace of mind—it’s best to take the extra step of removing shingles before installing a metal roof. Your home is worth the investment.If you’re ready to explore your options or have more questions, McCormick Roofing is here to help. Get in touch with us today to schedule a consultation. Together, we’ll ensure your home is protected and looking its best for years to come.
