If you’re thinking about upgrading your roof, the idea of adding a metal roof over your existing composite shingles may have crossed your mind. Metal roofs are becoming a popular choice for homeowners thanks to their durability, energy efficiency, and sleek appearance. But is it possible to install a metal roof over a composite roof? In this post, we’ll explore the pros, cons, and essential steps to help you decide if layering a metal roof over your composite shingles is the right move.
Why Consider Installing a Metal Roof Over Composite?
Time and Cost Savings
Removing an existing roof can be costly and time-consuming. By installing a metal roof over composite shingles, you can save on both labor and disposal fees associated with tearing off old materials. This approach can significantly reduce overall project costs.
Enhanced Energy Efficiency
Metal roofing is known for its excellent reflective properties. Installing a metal roof over composite can help reflect sunlight, reduce heat absorption, and potentially lower your energy bills, especially during hot summers.
Extended Lifespan of Roof
Metal roofs are long-lasting, with many lasting 40-70 years or more, while composite shingles generally have a lifespan of 20-30 years. By installing a metal roof over composite, you’re essentially giving your roof an upgrade in longevity and protection.
How Can You Install a Metal Roof Over Composite? The Steps
- Inspect the Existing Roof Structure
- Before making any decisions, have a professional inspect your current composite roof. Make sure there are no underlying issues like moisture buildup, leaks, or rotting that could affect the new metal installation.
- Add a Layer of Underlayment
- To ensure proper protection, add an extra layer of underlayment, such as felt paper or synthetic roofing underlayment, between the old roof and the new metal roof. This will add a buffer to protect against moisture and potential heat damage.
- Install Furring Strips (Optional but Recommended)
- Furring strips, or wood battens, can be placed between the metal roof and the composite shingles. This technique provides better ventilation, which can reduce heat buildup and moisture, both common issues in multilayered roofs.
- Secure the Metal Panels
- Once the underlayment and furring strips are in place, you can begin installing the metal panels. This step involves fastening the metal panels securely, ensuring the alignment is tight and even to prevent leaks or gaps.
- Check for Building Code Compliance
- Local building codes can vary when it comes to overlaying roofs. Before moving forward, confirm your plan aligns with local regulations. Some areas have specific codes that limit the number of roofing layers, especially if the combined weight may impact the home’s structure.
Benefits of Installing a Metal Roof Over Composite
Durability and Weather Resistance
Metal roofing is built to withstand harsh weather conditions, including hail, strong winds, and heavy rain. It’s a sturdy choice for any climate, and it’s less likely to suffer from cracks or breakage that can impact composite shingles over time.
Eco-Friendly Option
By keeping your composite shingles as a base layer, you’re reducing waste that would otherwise go to landfills. Metal roofs are also recyclable, which can make the entire project more eco-friendly.
Increased Home Value
A metal roof can increase your home’s resale value. Potential buyers may see the added roof layer as an attractive feature, especially when it comes to energy savings and the modern appeal of metal roofing.
Potential Drawbacks to Consider
Added Weight
While metal roofing is lightweight, it still adds weight to your home’s structure. If your home isn’t structurally sound enough to handle the added weight of a double roof layer, this could lead to issues over time.
Heat Retention
Although metal roofs reflect sunlight, the trapped air between the metal and composite shingles can occasionally cause heat buildup, especially without ventilation. Adding furring strips or ensuring proper attic ventilation can mitigate this problem.
Possible Issues with Moisture
Without proper installation, moisture could become trapped between the composite and metal layers, leading to mold or rot. Using high-quality underlayment and installing furring strips can minimize this risk, but it’s something to keep in mind when considering an overlay approach.
Final Verdict: Is Installing a Metal Roof Over Composite Right for You?
Installing a metal roof over composite shingles is generally safe, effective, and a budget-friendly option for many homeowners. It saves time, reduces labor costs, and minimizes environmental waste—all while giving your home a sleek, long-lasting roof. That said, proper installation is key. To avoid issues with moisture, weight, or heat buildup, work with a licensed contractor who has experience in layering metal roofs over composite.
If your current composite roof is damaged, unstable, or nearing the end of its lifespan, a full tear-off and replacement may still be the best option. However, if your composite shingles are in decent shape, adding a metal roof on top could be a wise investment.
FAQs
1. Is it safe to install a metal roof over composite shingles?
Yes, it’s safe when done correctly! By adding underlayment and furring strips and ensuring proper ventilation, you can minimize common risks like moisture and heat buildup.
2. Does installing a metal roof over composite add too much weight?
Metal roofs are relatively light, but the additional weight could be an issue for older homes. It’s best to consult a professional to assess the structural capacity of your home.
3. Will installing a metal roof over composite affect my home’s energy efficiency?
Yes, metal roofs are highly reflective and can improve energy efficiency by reducing heat absorption. The added layer can also provide extra insulation, depending on your setup.
4. Do I need to check building codes before installing a metal roof over composite?
Absolutely. Local building codes may limit roofing layers, so consult with a professional or your local building department before starting your project.
5. Can metal roofs be installed over damaged composite shingles?
No, if the composite roof is damaged or compromised, it’s best to repair or replace it before adding a metal roof to avoid structural and moisture problems.
6. How long will a metal roof over composite last?
Metal roofs can last up to 70 years or more, giving you a high-performance, long-lasting roof. The combined setup may require occasional inspections to ensure both layers remain intact.