If you’re considering installing a metal roof on your home, you may be tempted to save time and money by installing it over your existing shingles. However, as you’ll discover in the following seven reasons, this option may not always be the best choice.
Metal roofs are beautiful, durable, and long-lasting. They also keep homes cool in the summer and warm in the winter, but they do not fit over pre-existing roofs.
From increased weight and structural concerns to compatibility and warranty issues, the potential drawbacks of installing a metal roof over shingles far outweigh any perceived benefits. Keep reading to learn more about why you shouldn’t take the shortcut of installing a metal roof over shingles.
Why Installing A Metal Roof Over Shingles Is A Bad Idea
A metal roof installation can cause problems if it is installed over existing shingles. These problems include leaks and other issues that can lead to expensive repairs. It is usually better to remove the existing shingles before installing a metal roof to avoid these potential problems.
Below we’ve addressed some of the issues that can occur when you install a metal roof over shingles.
1. Increased Weight
Installing a metal roof over shingles can significantly increase the weight of your roof, and this added weight can have serious consequences. One major factor to consider is the age and condition of your home. If your home is older or the roof structure (rafters and trusses) or underlayment are not in good condition, the additional weight of the metal roof may be too much for it to bear. This can lead to structural problems or even collapse, which can be costly and dangerous.
Additionally, failing to properly reinforce the roof’s structure before installing a metal roof can also increase the risk of these problems occurring.
As a result, it is essential to carefully assess the weight-bearing capacity of your roof before proceeding with any roof installation. By taking the time to properly reinforce the roof structure and ensure that it can support the additional weight, you can help to protect your home and keep your family safe.
2. Structural Concerns
When you install metal roofs over a shingle roof, there are some important things to consider, including the potential structural issues of installing a metal roof over an existing shingle roof. The weight of a metal roof can put additional stress on an older home’s structure or on a roof that was originally built with wood framing.
You may need to reinforce your home’s structure before installing the new roof, which could be costly and time-consuming.
Additionally, different expansion and contraction rates between shingles and metal roofs can lead to compatibility problems when they are installed together. For example, leaks could develop if moisture gets trapped between the layers of shingles and metal. Therefore, it is important to carefully weigh these potential problems before proceeding with this type of installation.
3. Compatibility Issues
Installing a metal roof over shingles can lead to compatibility issues that can cause problems for your home. One major issue is that metal roofs and shingle roofs have different expansion and contraction rates due to temperature fluctuations.
When these two types of roofs are installed on top of each other, the differences in their ability to expand and contract can cause problems such as leaks and other issues. Additionally, the materials and installation techniques used for metal roofs are different from that of shingle roofs, which can create compatibility issues that can lead to problems such as poor adhesion of the roofing material, or gaps in the roofing system.
To avoid these issues, it is important to carefully consider the potential compatibility concerns of installing a metal roof over shingles before making a decision. By taking the time to properly prepare the roof, and ensure compatibility between the two types of roofing materials, you can help avoid potential problems and ensure the long-term performance of your roof.
4. Warranty Concerns
One potential disadvantage of installing a metal roof over shingles is the issue of warranties. Many metal roof manufacturers do not offer warranties for their products when they are installed over shingles. This means that if you experience problems with your metal roof, you may not be covered under the manufacturer’s warranty. This can be a significant concern, particularly if you are investing in a metal roof for its long-term durability and reliability.
In order to protect your investment and ensure that you are covered in the event of any problems, it is essential to carefully consider the warranty implications of installing a metal roof over shingles before making a decision. By taking the time to research the warranty policies of different metal roof manufacturers, and choosing a product with a strong warranty, you can help to ensure that you are protected in the event of any issues.
5. Reduced Energy Efficiency
Installing a metal roof over a shingle roof can also lead to reduced energy efficiency, which can have a significant impact on your home and your budget.
Metal roofs are generally more energy efficient than shingle roofs due to their reflective properties and ability to shed heat. However, when a metal roof is installed over shingles, the additional layer of shingles can create an extra barrier that traps heat, reducing the effectiveness of the metal roof. This can lead to higher energy bills and a less comfortable home.
To maximize the energy efficiency of your metal roof, it is important to carefully consider the potential impact of installing the roof over shingles before making a decision. By taking the time to properly prepare the roof and remove the existing shingles before installing the metal roof, you can help to ensure that the roof performs at its best, and helps to keep your home energy efficient.
6. Reduced Lifespan
Installing a metal roof over shingles leads to a reduced lifespan for the metal roof. Metal roofs are known for their long lifespans and durability, but when a metal roof is installed over shingles, the additional layer of shingles can create additional wear and tear on the roof. This can lead to an increased need for maintenance to check the potential problems that can shorten the lifespan of the metal roof.
By installing a metal roof on top of shingles, you may also be missing out on a chance to replace other crucial roofing components that can end up reducing the lifespan of the roof. For instance, if you install metal roofs directly over shingles, you may not be taking the roofing underlayment or decking into consideration. These roofing components face just as much wear and tear as the shingles installed on top, and if these components are damaged, the overall lifespan of the new metal roof will be reduced.
When installing a metal roof over shingles, it is important to carefully consider the potential impact of removing the existing shingles before starting work. By taking the time to properly prepare the roof and remove the existing shingles before installing the metal roof, you can help to extend the lifespan of the roof. This avoids problems that may be caused by having two different types of materials on top of each other.
7. Cost
Installing metal sheets over shingles can also lead to increased costs and expenses for the project. One major factor to consider is the need to remove the existing shingles before installing the metal roof. This can add to the cost of the project, as it requires additional labor and materials.
Additionally, the added weight of the metal roof may require additional structural reinforcement to ensure that the roof structure can support the additional weight. This can also add to the cost of the project. To avoid unexpected costs and expenses, it is important to carefully consider the potential cost implications of installing a metal roof over a shingle roof before making a decision. By properly preparing the roof and your budget for the project, you can help with making sure that the project stays on track and within your budget.
Should You Install A Metal Roof Over Shingles?
Ultimately, the decision to install a metal roof over shingles depends on your specific circumstances and goals. If you are looking for a quick and cost-effective way to get a new roof, installing a metal roof over shingles may seem like a good option. However, it is important to carefully consider the potential drawbacks of this type of installation before making a decision.
Final Thoughts
To ensure that you get the best performance and value from your metal roof, it is important to carefully consider these potential issues before making a decision. If you are considering getting a new asphalt shingles for your home, we recommend contacting Capital Roofing for expert advice and guidance. You can call us today at (918) 212-0849.
Our team of experienced roofers can help you to determine the right set of actions to take with your roofing project and ensure that your asphalt roof performs at its best. By working with Capital Roofing, you can feel confident that you are getting the best value and quality with your investment.
