Can You Install a Metal Roof Over Shingles? Guide to Installation, Costs, and Benefits

Can you install a metal roof over shingles? Yes, but only if your existing roof is in good shape and meets local building rules. Many homeowners choose metal roofing because it lasts longer. It helps save energy and needs less upkeep. However, putting a metal roof over existing shingles isn’t always simple. If not done right, it can cause moisture buildup, an uneven surface, or long-term damage.

Before making a decision, you should know:

• When you can (and can’t) install a metal roof over existing shingles
• The benefits and drawbacks of putting a tin roof over shingles
• Best metal roofing materials, including steel roof over shingles
• How the installation process works step by step
• Estimated costs and common mistakes to avoid

A steel roof over shingles can be a smart and budget-friendly upgrade. If you skip crucial steps like adding a protective layer, ensuring proper airflow, or using the right fasteners then you could face costly issues down the line. Whether you’re thinking about doing it yourself or hiring a professional, this guide will help you decide what’s best for your home.

Let’s get started!

What is a Standing Seam Metal Roof?

A standing seam metal roof is a strong and long-lasting roofing option. It has metal panels that lock together and run from the top of the roof to the edges. These panels create a smooth and continuous surface that helps keep water out.

Why Choose a Standing Seam Metal Roof?

• No Visible Screws – Fewer chances of leaks compared to roofs with exposed fasteners.
• Built to Last – Stands up well to strong winds, heavy rain, and snow.
• Modern & Stylish – Gives homes a clean and polished look. It can boost property value.
• Keeps Your Home Cooler – Reflects sunlight, which can help lower cooling costs in hot weather.

Since standing seam metal roofing locks together tightly, it is a great choice for installing over shingles. It offers better leak protection, a neat appearance, and lasts longer than many other roofing styles.

Why More Homeowners Are Choosing Metal Roofs

Many homeowners are switching to metal roofing because it offers:

• Longevity – Lasts 40 to 70 years, compared to 15–30 years for asphalt shingles.
• Durability – Withstands strong winds, hail, snow, and extreme heat.
• Energy Efficiency – Reflects sunlight and reduces cooling costs by up to 30%.
• Low Maintenance – Unlike shingles, metal doesn’t rot, crack, or require frequent repairs.
• Eco-Friendly – Metal roofs are often made from recycled materials and are 100% recyclable.

But before installing a steel roof over shingles, you must check if your home’s structure can support it and whether local building codes allow it.

Can You Install a Metal Roof Over Existing Shingles?

Yes, you can, but only if certain requirements are met. These are:

• Building codes allow it – Some areas require the old roof to be removed before installing metal.
• Your shingles are in good shape – If they are cracked, uneven, or damaged then they can cause issues for the new metal roof.
• Your roof structure is strong – Adding metal over old shingles increases weight, which could put stress on weak roofs.
• Ventilation is in place – Without proper airflow, moisture can build up and cause problems.

Pros & Cons of Installing a Metal Roof Over Shingles 

Thinking about putting a metal roof over your existing shingles? It can save time and money, but it’s not always the perfect solution. Here’s what you need to know before making a decision.

✅ Advantages

✔ Lower Cost – Saves $2,000–$5,000 by skipping the shingle removal.

✔ Quick Installation – A metal roof over existing shingles is 50% faster to install.

✔ Energy Efficient – Metal reflects sunlight and cuts cooling costs by up to 30%.

✔ Weather Resistant – Stands up to rain, snow, and strong winds.

✔ Eco-Friendly – Metal roofs are made from recyclable materials and reduce landfill waste.

❌ Disadvantages

🚨 Uneven Roof Surface – Old shingles can create bumps or waves under the metal panels.

🚨 Metal Roof Over Shingles Condensation – Without proper ventilation, moisture can get trapped, leading to mold or wood rot.

🚨 Louder in Rain – Without insulation, rain-hitting metal can be noisier than shingles.

🚨 Fastener Issues – If the screws don’t go deep enough into the main roof structure, they will only hold onto the shingles. Over time, this can cause the roof to become loose.

Best Metal Roofing Materials for Installing Over Shingles 

Selecting the right metal roofing material is key to durability, cost, and performance. Each type has its pros and cons. Here’s a simple guide to help you choose.

How is a Metal Roof Installed Over Shingles? (Step-by-Step Guide) 

Installing a metal roof over shingles can make your roof last longer and help lower cooling costs, but it must be done correctly. Follow these steps to ensure a durable and problem-free roof installation.

Step 1: Check Your Existing Roof

• Check for low spots, soft areas, or rotting areas.
• Ensure your roof has only one layer of shingles.

Step 2: Install a Protective Underlayment

Prevents water damage and excess heat buildup.

Best Underlayment Options:

• Synthetic underlayment – Waterproof and lasts longer.
• Sticky waterproof layer – Great for areas with heavy rain or snow.

Step 3: Add Furring Strips (Highly Recommended!)

• Creates a smooth and even base for the metal panels.
• Allows airflow to reduce moisture buildup.

Step 4: Install Metal Roofing Panels

• Fasten steel or tin roof over shingles with galvanized screws.
• Ensure screws go into the roof deck (not just the shingles).

Fastener Placement Tip: Screws should go through the raised parts (ribs) of the metal panels. Avoid placing them in the lower sections (valleys) to prevent leaks.

Step 5: Ensure Proper Ventilation

• Use ridge vents or soffit vents to let air flow and keep moisture from getting trapped under the metal roof.
• Not having vents is a common mistake. Without airflow, moisture can build up and cause mold, rust, and damage.

Cost Breakdown: How Much Does It Cost?

If you want an exact estimate, try an online roofing cost calculator for a personalized quote. Here’s the estimated price.

Should You DIY or Hire a Professional?

Thinking about installing a metal roof over shingles on your own? While some homeowners can tackle this project, it’s not for everyone.

You Can DIY If:

✅ Your roof is small, simple, and in good shape (no major repairs needed).

✅ You have roofing experience, the right tools, and time to do it properly.

You Should Hire a Professional If:

❌ Your roof is steep, complex, or has structural issues.

❌ You need permits, warranty protection, or expert installation to meet building codes.

❌ You want to avoid expensive mistakes that could lead to leaks or long-term damage.

If you want a durable, professionally installed metal roof, A1 Oasis Roofing has you covered. Our team ensures high-quality workmanship, proper installation, and long-lasting results. So you won’t have to deal with unexpected repairs or extra costs later on.

Tips to Avoid Common Mistakes

1. “Skipping the Protective Layer” → Fact: Underlayment is essential to prevent water damage, heat buildup, and mold. It’s a standard requirement in roofing.
2. “Not Securing Screws into the Roof Deck” → Fact: If screws don’t reach the roof deck then panels will loosen over time. It leads to leaks and structural damage.
3. “Blocking Airflow” → Fact: Poor ventilation leads to condensation under the metal roof, which can cause rust, mold, and wood rot. This is a major roofing issue.
4. “Using the Wrong Metal Panels” → Fact: Some metal panels require a smooth surface, and using the wrong type can cause leaks, poor installation, or a shorter lifespan.
5. “Forgetting That Metal Expands and Contracts” → Fact: Metal roofs naturally expand and contract with temperature changes. If not installed correctly, panels can warp, loosen, or cause screw failures over time.

Final Thoughts

Can you install a metal roof over shingles? Yes, but only if your existing roof is strong, level, and meets building codes. A metal roof over shingles can stay strong for years and help lower cooling costs. But skipping important steps, like adding a protective layer, can cause problems. If screws aren’t tight or air can’t flow, moisture can build up.

If you’re putting a tin roof over shingles, following best practices is crucial. A steel roof over shingles is an excellent investment, but proper installation is the key to its durability.

Looking for expert installation? Get professional roofing services from A1 Oasis Roofing to ensure your metal roof is secure, weather-resistant, and built to last for decades.