Metal Roof Over Shingles Without Furring Strips: A Step-by-Step Guide

Are you thinking about updating your home’s roof? If you have an asphalt shingle roof and are curious about the feasibility of putting a metal roof over shingles without furring strips, this detailed guide is for you. We’ll delve into how to go about this, the advantages, and what you need to think about when considering adding metal roofing on top of existing asphalt shingles here.

After reading this, you’ll be well-informed about this roofing alternative and ready to make knowledgeable choices for your roofing needs.

Can You Put A Metal Roof Over the Shingles?

Yes, in many situations, it’s possible to lay a metal roof directly over shingles. However, it’s vital to consult your local building authority first, since regulations differ from one place to another. Depending on your location, the code might allow for a metal roof to be installed directly over one or even two layers of existing shingles. Opting to install a metal roof on top of shingles can be a practical and often more advantageous route than fully tearing off and replacing the old roofing.

Why Choose A Metal Roof Over Shingles?

Opting for a metal roof to be installed over shingles is a wise decision, offering numerous advantages:

• Lifespan: Metal roof furring strips boast a remarkable durability of 40 to 70 years, depending on the material, which significantly outlasts the 20 to 30 years lifespan of traditional asphalt shingle roofs.
• Weather Resistance: Capable of withstanding severe weather conditions like hail, strong winds, and heavy snow, metal roofs offer superior durability.
• Energy Savings: Thanks to their heat-reflective properties, metal roofs can help reduce cooling costs during warmer months.
• Eco-Friendliness: Metal roofs are often manufactured from recycled content and are fully recyclable at the end of their service life, presenting a greener alternative to asphalt shingles, which frequently contribute to landfill waste.
• Cost Efficiency: By installing a metal roof over existing shingles, you can save on the expenses associated with labor and the disposal of the old roof.
• Low Maintenance: Metal roofs require minimal maintenance, as they are not prone to rotting, warping, or cracking, and are resistant to mold and mildew, simplifying home care.
• Flexible Installation: The subsequent sections will delve into how metal roofing can be directly placed over shingles, offering a cost-effective solution by reducing labor and minimizing environmental impact.

Benefits of Having a Metal Roof

Metal roofing offers the following significant benefits that make it an ideal choice for today’s homes. 

Energy Efficiency

Indeed, metal roof outperform traditional shingles and various other roofing materials in cooling efficiency during the warmer seasons. Their reflective coatings and thermal break designs can lead to up to a 20 percent reduction in cooling expenses.

By reflecting solar heat away from the structure, metal roofs significantly decrease the heat transferred into buildings, resulting in substantial savings on air conditioning costs.

Fire and Wind Resistant

Metal roof offer enhanced protection against fire hazards compared to traditional roofing materials like asphalt shingles. Due to their conductivity, metal roof can rapidly dissipate any electrical charge, such as from a lightning strike, across their surface without generating significant heat. This characteristic reduces the likelihood of fires starting as a result of lightning.

Moreover, the design of metal roof panels, which typically interlock or overlap, provides superior resistance to wind. This feature not only contributes to the overall durability and safety of the structure but also offers a significant advantage in areas prone to high winds.

50+ Year Life Expectancy

The higher initial cost of metal roofs compared to other materials can be attributed to their superior durability and longer lifespan, often extending up to 50 years. Unlike asphalt shingles, which may degrade over time due to exposure to wind, rain, snow, and ice, metal roof maintain their value and roof’s performance, offering prolonged protection against the elements. This resilience to extreme weather conditions also ensures that metal roof provide lasting benefits, making the investment more cost-effective over time due to reduced replacement and maintenance needs.

Adaptability

Metal roofs offer exceptional versatility in design, making them suitable for a broad range of architectural styles. With an array of metal materials available, they can cater to diverse roofing requirements, including options that replicate the look of wood, slate, tile, and shingles.

This adaptability ensures that regardless of your home’s design or the intricacy of your roof’s structure, you can find metal roofing options that align with your aesthetic preferences and functional needs. This variety enables homeowners to enjoy the durability and efficiency of metal roofing without compromising on style.

Lightweight

The selection of roofing material is crucial, especially considering the potential for walls to sag and fail under excessive weight. This issue becomes increasingly critical along extended walls, in areas with a history of leaks, heavy traffic impact on foundations, or in older homes where the structural integrity may be compromised over time. A heavy roof can exacerbate these problems, leading to significant roof damage.

Metal roofing stands out as one of the lightest options available for residential properties, offering a solution that mitigates the risk of structural damage. Its lightweight nature plays a vital role in safeguarding homes from the adverse effects of structural shifts and damages, particularly in regions prone to seismic activity. By choosing metal roofing, homeowners can enhance their home’s resilience against such challenges, ensuring long-term stability and safety.

Cost to Install a Metal Roof

Installing metal roof involves a sophisticated process, underscoring the importance of engaging with a skilled and experienced roofing professional to oversee the installation process. Given the higher cost of materials, the installation of a metal roof may be at the upper end of the pricing spectrum. Nonetheless, the extensive and significant advantages of metal roofing justify the investment.

The superior durability of metal roof, proven to endure severe weather conditions, along with their long lifespan, ensures that your home remains secure against adverse elements for many years. This peace of mind and the protection it affords invest in metal roofing a wise decision for homeowners.

What are the disadvantages of laying a metal roof over shingles?

1 )The concern about additional weight is valid, especially over the long term.

Homes are generally constructed to support the weight of a single roof. If your house isn’t newly built, it’s plausible that the existing shingles were laid on top of a previous layer. Adding a metal roof into the mix means your structure could end up supporting three layers of roofing material, despite being designed for just one. Over time, as the structural components like joists and the subroof, along with the original shingles, begin to deteriorate, there could be a risk of buckling or other forms of damage.

However, this concern is mitigated somewhat by the fact that metal roofing is typically much lighter than other materials. Provided there’s only a single layer of metal shingles in place and your home isn’t particularly old, the risk associated with the extra weight of a full metal roof over shingles shouldn’t be overly significant.

2) Metal roofing is indeed on the pricier side, with costs ranging from $120 to $900 per square foot.

Despite the initial investment, its exceptional durability means it’s unlikely you’ll need to replace your roof again in the foreseeable future. A notable characteristic of metal roof is their sound during rain; however, the noise level inside the house should be minimal, especially if the original shingle roof remains underneath, providing additional insulation to mute the sound.

For those looking to make metal roofing more budget-friendly, opting for aluminum or galvanized steel can be a cost-effective choice, as these materials are generally less expensive in the realm of residential metal roofing.

If the project involves a smaller structure, like a shed roofing, corrugated steel presents the most economical option. Nevertheless, for the utmost in cost and energy efficiency alone, existing asphalt shingles remain the leading choice. They offer a low-cost solution, although it’s worth noting that while repairs can be inexpensive, they may not offer long-term durability.

For roofs that are over 15 to 20 years old, considering a complete replacement might be a more prudent decision, ensuring the longevity and integrity of the roofing structure.

Can I install metal roofing over shingles on my own?

1 )You can if you have roofing experience, but it’s not recommended otherwise.

Roof work inherently carries risks, and installing metal roofing solid decking amplifies these challenges due to the necessity for teamwork, specialized equipment for hoisting and placing the panels, and the significant consequences of incorrect installation techniques. Considering all these factors, it’s both generally recommended and advisable to enlist a professional for such a project. However, if you possess considerable roofing experience, you might feel confident undertaking this task yourself.

• The investment for a metal roof can range between $15,000 and $60,000, varying with the roof’s performance size and the chosen material. While this outlay is considerable, the long-term benefit is substantial, as old roof require little to no maintenance for 40 to 50 years post-installation process.
• For those lacking experience in roofing but looking to dip their toes into a project of lesser scale and risk, such as a shed, attempting metal roofing could be feasible. In these scenarios, the dangers, particularly the risk of falling, are significantly reduced, making it a more approachable task for beginners.

2) It’s typically illegal to install roofing like this without a permit.

For minor roof repairs or patching, you’re generally permitted to proceed without a permit. However, installing a brand-new roof typically requires one. If you’re pondering the DIY route for your roofing project, it’s crucial to contact your local building department to apply for the necessary permit.

• Be aware that your locality might have regulations restricting roof work to licensed contractors only. This means that, depending on where you reside, undertaking a roof renovation on your own might not be legally permissible if you’re not a licensed professional.
• When considering professional help, know that many roofing contractors offer free estimates. It’s a good practice to reach out to several contractors for quotes. Arrange meetings to discuss the project specifics and gauge what each will charge. It’s also essential to verify that any roofing contractor you’re considering is properly licensed at both the city and state levels. This ensures that the work will be up to code and that you’re engaging with a qualified and reputable professional.

What is the best way to install a metal roof over shingles?

The preferred method for installing a new roof involves the initial placement of battens, which are either 2 by 2 inches (5.1 by 5.1 cm) adding wood stripping or 1 by 2 inches (2.5 by 5.1 cm) boards, arranged in horizontal and parallel furring of wood strips over the existing shingle roof. This technique serves to create space between the metal panels and the shingle layer beneath, accommodating the natural expansion and contraction of the metal due to temperature fluctuations.

Besides allowing for thermal expansion and movement, this gap plays a crucial role in preventing the accumulation of moisture between the metal and shingle roof layers, significantly reducing the risk of water shield damage. Additionally, in the event of a new metal roof leak, the presence of shingles beneath—with the maintained gap—provides an extra layer of protection, ensuring the overall safety of the roof structure.

This installation approach, by facilitating a margin of error for environmental and temperature changes, and offering a safeguard against leaks, underscores the importance of proper ventilation system planning and execution in metal roofing projects.

Can you put metal roof deck on top of damaged shingles?

If your shingles are in poor ventilation condition, or showing signs of damage or leaks, it’s necessary to remove them before proceeding with metal roofing installation. Many homeowners consider overlaying new roof on existing shingles as a cost-saving measure, especially when faced with the need to replace worn-out shingles. However, this approach is not advisable in cases where the underlying shingles are compromised.

• In such situations, a roofing contractor must remove the shingles, assess and repair any underlying structural issues, such as damaged or decaying joists, and then proceed with installing the metal roofing directly onto the cleaned and prepared framing.
• Installing metal roofing over a damaged current shingle roof can lead to further complications. The additional weight of the new metal roof over shingles may exacerbate the condition of the weakened shingles, potentially leading to their collapse over time.
• Therefore, when dealing with damaged shingles, an inspection by a professional is essential to determine the extent of the underlying damage. The need for removal becomes unavoidable to ensure the structural integrity of the roof and the successful installation of the new metal roofing.

Do I need underlayment for metal roof over shingles?

1) Yes, installing an underlayment before laying metal roofing or battens isn’t strictly necessary if the roof deck existing shingles are in excellent condition. Underlayment serves as a protective layer, designed to absorb moisture and mitigate the severity of leaks, providing an additional barrier against water infiltration.

The most commonly used underlayment in roofing projects is 30# roofing felt. Some contractors may opt to place plywood over the battens, securing the felt onto this plywood layer before proceeding with the metal roofing installation. However, this method significantly increases the weight on the roof’s structure. Consequently, if the shingles are particularly thick and in good shape, which already offers a substantial protective layer, this additional step and the added weight it brings may be deemed unnecessary.

This approach allows for a balance between ensuring adequate roof protection and managing the structural load, especially in cases where the existing shingle layer is considered sufficiently robust to underpin the new metal roofing without the need for added underlayment layers.

2)Incorporating an underlayment beneath your install metal roofing serves as a prudent safety measure, offering an additional layer of protection. This barrier is instrumental in moisture absorption, leak prevention, and safeguarding the underside of your metal roofing panels from potential damage. Given its relatively low installation cost, opting for an underlayment provides valuable peace of mind without a significant financial burden.

Even in scenarios where it might not be strictly required—such as when existing shingles are in good condition—the benefits of having that extra layer of defense against moisture and leaks make it a worthwhile consideration for enhancing the durability and integrity of your roofing system.

How are the metal sheets installed over shingles?

1) Screw or nail the underlayment in place and screw the roofing. If the shingles are in good shape then lay the felt underlayment flat on the roof that was previously. Make use of a nail gun, or hammer with a nail for securing the felt onto the plywood or new underlayment and the roofing shingles. Next, apply nails 2 by 2 inches (5.1 by 5.1 cm) or 1 by 2 inches (2.5 in by 5.1 centimeters) boards on horizontal or parallel rows across the roof.

If you think the shingles aren’t in good health then you’ll need to take off the shingles before doing so.

Battens are the only element of the procedure that makes it distinct in comparison to a typical new metal roof over shingles construction.

2) Install the panels and attach them to battens. You may need a team for this. Take the sheet of metal towards the roof, and then attach them to battens, or to the subroof for securing the sheets in place. They are usually big and heavy, which is one layer why it could take a while to tie the seams of wood strips on each sheet so that the space is symmetrical.

If the grooves in the panels of metal aren’t level when laid side-by-side you’ll have to trim these panels so that the seams coincide.

3) Use closure furring strips to cover the seams and apply the flashing. Once the metal sheeting is all installed correctly, you can cover every seam between two sheets with foam or rubber closure furring strips. They will also prevent leaks and stop the water from getting into the roof. Flash the roof by wrapping the edges of your roof using drip edges and also the apex roof using the roof cap. Fix the flashing in place by screwing it onto the edge and/or battens that are under the roof.

Secure each nail or screw that is visible on the grommet of rubber to prevent small gaps between screws and roof to prevent water from getting in.

In terms of roofing jobs can be considered, install metal roofing is extremely simple and easy to put up. It’s a lot simpler to simply lay sheets of metal on top of each other than to install individual shingles, or to secure rubber slate.

Metal Roof Over Shingles Problems

While installing a roof constructed of metal on shingles is a great idea, it can have its benefits However, there could be concerns that you must be conscious about. Being aware of these concerns and options will allow you to make an educated decision and ensure the successful completion of your project.

1. Moisture Construction: One common issue is an accumulation of water in between the roof constructed of metal and old shingles which can cause the development of mold and decay. To stop this from happening it’s essential to have a well-ventilated roof or install an artificial sublayment to create an effective barrier to the moisture.
2. irregular surfaces The other issue can be caused by the lack of level in the shingle’s layer this could lead to the panel’s metal being installed incorrectly. To solve this issue you should think about adding furring strips or a layer of level on the shingle before installation to ensure a safe and perfect fit.
3. Additional Roof Weight: Adding a roof constructed of metal on top of shingles can make it heavier over the whole structure of your home. To avoid structural issues, you should consult an expert to assess the ability of your home to handle the additional weight and also to determine whether you need to strengthen.
4. An old roof problem: Problems with the roofing shingle, such as water leaks, and structural problems, cannot be resolved by the construction of an aluminum roofing top. The issues may cause further problems.
5. Building code violations Check with the building department in your area about the rules for putting up the roof with a metallic material to avoid fines or penalties.
6. Lesser leaks can be hard to find: It can be difficult to find and fix leaks on a roof that is fitted over shingles since water could pass between layers, and then discover the way through the least resistance.
7. Warranty: The installation of an aluminum roof on top of shingles can void your warranties. Contact the roofing company that made your shingles, and review the conditions of the warranty to ensure the installation doesn’t void your warranty.

By educating yourself on the issues that they may cause and the solutions they offer to them, you’ll be more equipped to ensure the success of the install metal roofing you choose to install over the roofing shingles you have in place. Consult with specialists to resolve any problems or concerns that are related to the task you’re involved in.

Cost Considerations When Installing Metal Roofing Over Shingle

Install metal roofing system over shingles is a matter of weighing expenses like material, labor costs, as well as location. This chapter explains the major aspects that impact the costs of making an informed choice.

• Materials: One of the primary aspects that determine price is the kind of metal material selected. The most common roofing materials are steel copper, aluminum, and zinc. Each has the price of its own. Aluminum and steel tend to be cheaper, however zinc and copper are higher priced because of their strength and attractive appearance. The quality and thickness of the metal can also affect the cost.
• Labor: Labor costs can also be quite different, contingent on the size of the job and the knowledge that the company has. It is important to obtain multiple estimates from reliable installers to make sure you’re getting an affordable price for the project. Remember the fact that hiring a professional installer can cost you less in the end because it will avoid any issues that could arise due to a poor installation.
• Locality: The location of your residence can have a significant impact on the expense of putting up an aluminum existing roof on top of shingles. Local construction codes, weather conditions as well as accessibility could affect the cost. In particular, houses in areas where snowfall is heavy might require structural strengthening and increase the total cost.
• Old Shingles Removal and Installing Them Over Them: A crucial thing to think about as well is the choice between getting rid of the shingles or placing the roofing made of metal directly on top of the old shingles. The choice you make will greatly affect both the cost of the work and also the possibility of further repair costs.

Final Metal roof over shingles without furring strips

In the end, the choice to put up a roofing over shingles is based on the individual’s preferences, your budget, and your local building code. The option offers a variety of advantages, such as cost savings in addition to increased durability and enhanced insulation. It is important to consider the advantages and disadvantages and seek out a professional roofing expert to assess whether this option is suitable for your house.

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