The United States is home to a vast amount of commercial and industrial rooftops, and a large chunk of these are in urgent need of repairs. For contractors, there’s a smart fix: putting in metal roofs right over the old shingles. This method is not only convenient for building owners aiming to extend the life of their roofs, but it also cuts costs and spares them the hassle of removing the old roof.
Why Choose Metal Roofs Over Shingles?
Shingles might not break the bank, but they don’t last long, needing regular maintenance and replacement. This cycle of fixing and replacing can be tiring for owners, not to mention it can mess with their business activities. Metal roofing, however, offers a break from this repetitive cycle.
Sure, metal roofs might seem pricier at first compared to new shingles, but they’re worth the investment. Metal roofs can shield your building for over 50 years with hardly any need for fixes—that’s two to three times longer than shingle roofs! Plus, they spruce up your building’s look with a range of designs and colors.
Beyond the long life and style, metal roofs are eco-friendly. They’re often made from recycled materials and can be completely recycled after their service life, making them a green choice for property owners. Shingles, on the other hand, aren’t typically reused, and because they’re so common in dumps, getting rid of them can cost you a pretty penny.
Choosing to install a metal roof over the old shingles is a wise move. It dodges the costs and trouble of tearing off the old roof. What’s more, you get all the perks of a metal roof—durability, style, and an eco-friendly footprint.
Metal Roofing Over Existing Shingles Options
Ready to leave behind the endless cycle of shingle upkeep and embrace metal roofing? The next step is to pick the right method for layering metal panels over your current shingles. There are several standard methods, but let’s discuss the most popular one.
Fixing Metal Panels Using Wooden Strips
One common technique involves using wooden strips, known as purlins or sub-girts, as a base. These strips are laid across the old shingle roof and securely fixed to the structure underneath. You can place this wooden grid directly on top of existing shingles, over the old decking, or as an underlayment layer. The new metal roofing panels are then fastened to this wooden framework. The image provided offers a basic view of how this setup works, but keep in mind there are many variations to tailor it to specific needs. This method is usually less disruptive than removing the entire old roof.
However, you should note that even though this method may save you from the mess of a full roof removal, the costs of the extra materials and labor for installing the wooden strips can add up, bringing the price close to what a full tear-off might be. But this method is still more eco-friendly—you don’t have to dispose of the old shingles. It does, however, add more weight to your roof, so it’s crucial to check if your building can handle the extra load.
If you go with this method, be cautious if using pressure-treated lumber, as the copper in the wood can corrode the metal panels. To prevent this, a layer of #30 felt, or a synthetic underlayment should be placed between the pressure-treated wood and the metal panels.
Metal Panel Attachment Directly into Shingles
Choosing to attach metal panels right over the shingles into the wood deck is a budget-friendly option. This method skips the cost and effort involved in installing wooden furring strips. However, there’s a catch: steel reflects any unevenness from the deck or shingle surface below, leading to a bumpy appearance on your metal panels.
This issue is all about looks—it won’t impact the performance of the panels. But for those who prize curb appeal, considering a full shingle removal or opting for a specialized system like the 138T might be the way to go, which we’ll talk about shortly.
There are other things to think about with this direct-to-shingle method. It makes it tough to include Above Sheathing Ventilation (ASV), which is a key player in cutting down your cooling costs. So, while it may be easier on your wallet now, you might miss out on some energy savings later on.
Also, a protective layer between the old shingles and your new metal roof is a must when going for direct attachment. This barrier is crucial to stop the old shingle material from damaging the metal panels as they move with temperature changes. Common materials for this layer include #30 felt, synthetic liners, or even slim panels of foil-faced foam insulation.
Shingle Recover Systems
Our unique 138T Shingle Recover System presents a third path for roof renovation. This method bypasses the expense and effort of the wood strip installation we discussed before. Its clever clip design isn’t just for looks—it enhances them. More crucially, it introduces an Above Sheathing Ventilation (ASV) space, which is a big deal for those looking to improve energy efficiency.
What sets the 138T panels apart is their symmetrical design. This might sound similar to asymmetrical standing seam panels, but the difference goes beyond the ‘s’ in the word. The impact on the roof installation process and long-term maintenance is significant.
Symmetrical panels, like those in our 138T system, offer flexibility—they can be installed or replaced in any sequence. On the flip side, asymmetrical panels need to be laid down in a specific order, usually from one side to the other. If damage occurs, and you’re dealing with asymmetrical panels, get ready for a time-consuming fix that often means removing undamaged panels just to get to the problem areas, which can balloon repair costs and waste materials.
In contrast, if a symmetrical panel system ever needs attention, it’s a hassle-free job. Contractors can directly target and fix the exact spot that needs work, saving time and cutting down on unnecessary expenses and waste.
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FAQ 1: Can you install metal roofing directly over old shingles?
Answer: Yes, you can install metal roofing directly over old shingles. This is a cost-effective and less disruptive method of roofing. By doing so, you avoid the expenses and labor associated with tearing off the old shingles. However, it’s important to install a protective barrier between the shingles and the new metal roof to prevent potential wear.
FAQ 2: What are the benefits of installing metal roofing over shingles?
Answer: Installing metal roofing over shingles offers several benefits:
- Longevity: Metal roofs can last significantly longer than traditional shingle roofs, often upwards of 50 years.
- Cost Savings: You save on labor and disposal costs associated with removing the old shingles.
- Quick Installation: The process is typically faster because you’re not removing the old roof.
- Environmental Impact: Less waste is sent to landfills since the old shingles are not removed.
- Energy Efficiency: Certain methods, like using the 138T Shingle Recover System, provide Above Sheathing Ventilation (ASV) which can help in reducing energy costs.
FAQ 3: Does installing a metal roof over shingles cause any damage to the roof?
Answer: No, installing a metal roof over shingles does not inherently cause any damage to the roof structure, provided it is done correctly. It’s crucial to assess the structural integrity of the existing roof to ensure it can support the additional weight of the metal roofing. Professional installation is recommended to avoid any issues such as improper alignment or inadequate ventilation.
FAQ 4: Will a metal roof installed over shingles be less durable or have a shorter lifespan?
Answer: A metal roof installed over shingles should not have a reduced lifespan or durability if installed correctly. In fact, metal roofs are known for their durability and can have a longer lifespan than traditional shingle roofs, often by several decades. The key is ensuring proper installation techniques and using quality materials, including the correct barrier and ventilation system if necessary.
FAQ 5: Is it possible to install metal roofing over two layers of shingles?
Answer: While it is technically possible to install metal roofing over two layers of shingles, most building codes only allow for two roofing layers on a structure. Additionally, installing over two layers of shingles can add significant weight to the roof’s structure and may not provide the best conditions for the metal roof. A thorough inspection by a structural engineer is recommended to determine if this is a safe and viable option for your specific building.