Can Metal Roof Go Over Shingles?

Last updated on January 30, 2024

Yes, a metal roof can be installed over shingles, provided that local building codes and regulations are followed, and appropriate underlayment and ventilation measures are in place.

Are you considering installing a metal roof over your existing shingles? Well, you’re not alone. Many homeowners are opting for this option as it can save time and money.

However, before making any decisions, it’s important to understand if a metal roof can indeed go over shingles. In this article, we’ll explore the advantages and disadvantages of installing a metal roof over shingles and provide you with all the information you need to make an informed decision for your roofing project.

So let’s dive in!

Can Metal Roofs Be Installed Over Shingles?

can metal roof go over shingles

If you’re wondering whether a metal roof can be installed over shingles, the answer is yes. However, there are some important factors to consider before making this decision.

One of the main advantages of installing a metal roof over shingles is that it can save time and money on labor costs since there’s no need to remove the existing roofing material. Adding another layer of protection on top of your old shingle roof will provide extra insulation and soundproofing.

However, compatibility issues between different types of roofing materials must be taken into account when considering this option. The weight factor also needs consideration as two layers may exceed building codes’ maximum load capacity for your home’s structure.

It’s essential to consult with an experienced roofer who has expertise in installing metal roofs over existing ones before proceeding with any installation project involving multiple layers or materials.

Shingle Roofing Overview

Shingles are made from various materials, including asphalt, wood, slate, and clay. Asphalt shingles are the most commonly used type of shingle in North America because they offer durability at an affordable price point.

However, over time shingles can become damaged or worn out due to exposure to harsh weather conditions such as wind and rain. When this happens it’s important to consider your options for repair or replacement.

One option that many homeowners consider is installing a metal roof over their existing shingles instead of completely removing them before installation. This can save time and money on labor costs while still providing the benefits of a new metal roof such as energy efficiency and longevity.

Advantages of Metal Roofs Over Shingles

They offer several advantages over traditional shingle roofing systems. Firstly, metal roofs are incredibly durable and long-lasting.

Unlike shingles that can deteriorate over time due to weather exposure, metal roofs can withstand harsh elements such as wind, rain or snow without showing signs of wear and tear.

Secondly, metal roofing is energy-efficient which means it reflects heat from the sun rather than absorbing it like asphalt shingles do. This helps keep your home cooler during hot summer months while reducing your cooling costs.

Thirdly, a properly installed metal roof requires little maintenance compared to other types of roofing materials such as wood shakes or tiles that require regular upkeep to prevent damage from moisture buildup or insect infestations.

Lastly but not least important is the aesthetic appeal of a new shiny metallic roof on top of an old worn-out one! Metal roofs come in various colors and styles giving homeowners more options when choosing their preferred look for their homes’ exterior design.

Compatibility Factors

Not all types of metal roofing are suitable for installation over shingles. For example, some standing seam metal roofs require solid decking and cannot be installed directly on top of the existing shingle layer.

The type and condition of your current roof will also play a role in determining whether or not you can install a new metal roof over it. If your current roofing system has any damage or structural issues that need to be addressed before installation can take place, this may impact compatibility as well.

It’s essential to consult with an experienced roofing contractor who specializes in installing metal roofs before making any decisions about whether or not you should install one over your existing shingle layer. They’ll assess the condition of both layers and determine if there are any potential issues that could arise during installation.

Structural Considerations

The added weight of the new roofing material can put stress on your existing roof structure and may require additional support. It’s essential to have a professional inspect your roof and determine if any reinforcement is necessary before proceeding with installation.

You should also consider the pitch or slope of your current shingle roof. Most metal roofs require at least a 3:12 pitch for proper water drainage, so if you have a low-pitched or flat shingle roof, it may not be suitable for installing metal roofing without significant modifications.

While installing a metal roof over shingles can save time and money in some cases; homeowners must take into account their home’s structural considerations before making this decision.

Installation of Metal Roofing Over Shingles

However, there are some important considerations that need to be taken into account. First and foremost, it’s essential to ensure that your existing shingle roof is in good condition before proceeding with the installation of a metal roof.

Once you’ve confirmed that your current roofing system is sound and meets local building codes and regulations, you can begin preparing for the installation of your new metal roof. The first step involves cleaning off any debris or loose material from the existing shingles.

Next up is laying down an appropriate underlayment on top of the old shingles before installing new flashing around all penetrations such as chimneys or vents. This will help prevent water infiltration between layers while also providing additional insulation benefits.

After this has been completed successfully, fasteners should be installed through both layers at strategic intervals according to manufacturer specifications for optimal performance during high winds or other extreme weather conditions.

Trim pieces must be added along edges where two different materials meet (such as where walls meet roofs) so they blend seamlessly together visually while also preventing moisture intrusion into these areas over time.

Manufacturer Specifications and Warranty

Each manufacturer has its own set of instructions for installation, which must be followed precisely to ensure that the warranty remains valid. Failure to adhere to these guidelines can result in damage or failure of the roofing system.

Before purchasing any metal roofing materials, make sure you research different manufacturers and their products thoroughly. Look for reputable companies with a proven track record of quality products and customer service.

Pay close attention to each product’s warranty terms before making your final decision on which one is right for you. Warranties vary from company-to-company but typically cover defects in material or workmanship under normal use conditions.

Fastener Application

The fasteners should be long enough to penetrate through both the metal roofing and shingle layers and into the decking below. Using shorter nails or screws can cause leaks as they won’t hold up against strong winds or heavy rain.

It’s also essential to choose corrosion-resistant fasteners that are compatible with your chosen metal roofing material. For example, if you’re using aluminum panels, make sure you use stainless steel screws instead of galvanized ones that may corrode over time.

Another crucial factor is spacing between each screw or nail used in securing your new roof system in place. Too much space between them can lead to gaps where water could seep through during heavy rainfall events while too little space could result in buckling due to thermal expansion and contraction cycles.

Trim

Trim refers to the metal pieces that are used to cover and protect roof edges, corners, and other vulnerable areas. It also provides a finished look to your roof.

When installing a metal roof over shingles, trim is necessary for several reasons. First off, it helps prevent water from seeping into the gaps between your old shingle roofing and new metal panels.

Secondly, trim can help improve ventilation by allowing air circulation under the eaves.

There are different types of trims available in various shapes and sizes that you can choose from depending on your preference or building design requirements. Some common types include drip edge flashing (used along eaves), gable trim (used at gable ends), ridge cap (covers peak area) among others.

Safety

The process involves working at heights, handling heavy materials, and using power tools. Therefore, it’s essential to take all necessary safety precautions to prevent accidents and injuries.

Before starting the installation process, ensure that you have the appropriate safety gear such as gloves, hard hats, eye protection goggles or glasses with side shields for debris protection; slip-resistant shoes or boots with good traction; fall arrest systems like harnesses and lanyards if working on steep roofs.

  • Additionally:
  • Ensure that your ladder is secure before climbing up.
  • Avoid stepping on any loose shingles while walking on the roof.
  • Use caution when handling sharp metal edges during cutting or trimming of panels.
  • Keep children away from work areas
  • By following these simple guidelines along with other recommended safety measures in your area will help keep you safe throughout the installation process.

Ventilation Concerns

Without adequate ventilation, moisture can build up between the layers of roofing and cause damage to both the metal roof and underlying shingles. This can lead to mold growth, rotting wood decking or even structural damage.

To prevent these issues from occurring, it’s important to ensure that your attic space has sufficient airflow before installing a metal roof over existing shingles. Proper ventilation will help regulate temperature and humidity levels in your attic space while also preventing moisture buildup.

There are several options for ventilating an attic space including ridge vents, soffit vents or gable vents. It’s essential that you consult with a professional roofer who understands local building codes and regulations when determining which type of venting system is best suited for your home.

Metal Roof Over Shingles Condensation

Moisture can accumulate between the old and new roofing materials, leading to mold growth, rotting of wood decking, and other issues. To prevent condensation from forming under your metal roof, proper ventilation must be installed.

Adequate ventilation allows air to circulate freely in the attic space or beneath the roofing material. This helps regulate temperature and humidity levels while preventing moisture buildup that can lead to condensation.

There are different types of vents available for use with metal roofs over shingles such as ridge vents or soffit vents which allow air flow through them into your attic space. It’s important that these are properly installed by an experienced professional who understands how they work together with insulation systems in order not only prevent moisture but also improve energy efficiency.

Energy Efficiency

Metal roofs reflect solar radiant heat, which can help reduce cooling costs during hot summer months. This reflective property also helps to keep your home warm in winter by preventing heat from escaping through the roof.

Moreover, some metal roofing products are coated with special pigments that increase their solar reflectance and thermal emittance properties further. These coatings can significantly improve energy efficiency and reduce your carbon footprint.

In contrast, asphalt shingles absorb more heat than they reflect, making them less efficient at regulating indoor temperatures. They tend to trap hot air inside homes during summers and lose warmth quickly in winters.

Longevity and Durability

Metal roofs are known for their exceptional strength, resistance to harsh weather conditions, and long lifespan. Unlike traditional asphalt shingle roofs that typically last between 15-20 years, metal roofing can last up to 50 years or more with proper maintenance.

Metal roofing materials such as aluminum, steel, copper or zinc have high resistance against fire damage caused by lightning strikes or wildfires. They also do not rot like wood shakes nor crack like clay tiles under extreme temperatures.

Moreover, they require minimal maintenance compared to other types of roofing systems which means you’ll save money on repairs in the long run. Many manufacturers offer warranties ranging from 30-50 years depending on the type of material used.

Building Codes and Regulations

Before installing a metal roof over shingles, it’s important to check with your local building department for any specific requirements or restrictions in your area. Some areas may require a permit for this type of installation, while others may prohibit it altogether.

In addition to permits and restrictions, there are also safety standards that must be met when installing a metal roof over shingles. For example, the added weight of the new roofing material can put stress on the underlying structure if not properly supported.

This is why structural considerations should always be taken into account before proceeding with an installation.

Environmental Impact

On one hand, by choosing a metal roof, you’re opting for a more sustainable roofing material that can last up to 50 years or more with proper maintenance. This means fewer resources used in manufacturing and less waste generated from frequent replacements.

On the other hand, if your existing shingle roof contains asbestos or other hazardous materials that need special disposal methods during removal before installation of the new metal roofing system; this could have an adverse effect on the environment. Improper installation techniques can lead to leaks which may cause water damage leading towards mold growth.

It’s important always to work with licensed professionals who follow local building codes and regulations when installing any type of roofing system over existing materials.

Maintenance Requirements

One of the main advantages of installing a metal roof over shingles is that it reduces the need for frequent repairs and maintenance. However, you should still inspect your roof regularly to identify any potential issues before they become major problems.

One important aspect of maintaining a metal roof is keeping it clean. Dirt, debris, and other materials can accumulate on your roof over time and cause damage if left unchecked.

Regular cleaning with water or mild detergent can help prevent this buildup from occurring.

Another key factor in maintaining a metal roof is ensuring proper drainage. Metal roofs are designed to shed water quickly but standing water can lead to corrosion or leaks over time if not addressed promptly.

Be sure to address any issues with fasteners or sealants immediately when identified during inspections so that small problems don’t turn into larger ones down the road.

Aesthetics and Visual Appeal

Metal roofs come in a wide range of colors, styles, and finishes that can complement any home’s architectural style. Metal roofs are available in various textures that mimic traditional roofing materials like wood shakes or clay tiles.

When installing a metal roof over shingles, homeowners have the option to choose from different profiles such as standing seam or corrugated panels. These profiles offer unique visual appeal while providing superior protection against harsh weather conditions.

Moreover, unlike asphalt shingles which tend to fade over time due to exposure to sunlight and other elements; metal roofs retain their color for decades without fading or losing their luster.

Noise Insulation

The sound of raindrops hitting a metal surface can be quite loud, and some people worry that it will disturb their peace and quiet. However, modern metal roofing systems are designed to provide excellent noise insulation.

In fact, many manufacturers offer specialized underlayment materials that help reduce the amount of noise transmitted into your home. Installing an attic space with proper ventilation can also help dampen any sounds from outside.

It’s important to note that while there may be some increase in sound levels during heavy rainfall or hailstorms compared to traditional shingle roofs; this should not deter you from choosing a metal roof if it meets your needs in other areas such as durability or energy efficiency.

Final Thoughts

It’s important to note that this process requires careful planning and execution by experienced professionals who understand the nuances of metal roofing installation. While there are many advantages to choosing a metal roof over shingles, it’s essential to consider all factors before making any decisions.

Ultimately, your choice will depend on your specific needs and preferences as well as local building codes and regulations. If you’re unsure about whether or not a metal roof is right for you or have questions about the installation process, don’t hesitate to consult with a professional roofer.

With proper planning and execution, installing a new metal roof can provide long-lasting protection against harsh weather conditions while also enhancing the overall aesthetic appeal of your home. So why wait? Contact us today if you’re ready to take advantage of all that modern-day roofing technology has in store!

FAQ

What happens if you put a metal roof over shingles?

Installing a metal roof over shingles is absolutely fine, as metal roofs are lightweight, fast to install, and come in large sheets rather than individual tiles.

Can you put a metal roof directly over a shingle roof?

Yes, you can put a metal roof directly over a shingle roof due to its lightweight nature, making it suitable to be installed over existing shingles.

Is it better to remove shingles before installing metal roof?

Yes, it is better to remove shingles before installing a metal roof if the asphalt shingles are rough or uneven, or if the deck sheathing shows signs of rot and requires repairs.

What are the potential drawbacks of installing a metal roof over existing shingles?

Potential drawbacks of installing a metal roof over existing shingles include added weight, trapped moisture, and uneven surfaces.

How does the weight of a metal roof compare to that of shingles, and will it affect the overall structure?

The weight of a metal roof is generally lighter than that of shingles, and it typically has minimal impact on the overall structure.

Are there any specific building codes or regulations to consider when installing a metal roof over shingles?

When installing a metal roof over shingles, it is essential to consider local building codes and regulations that may require proper ventilation, underlayment, and adherence to installation guidelines.

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