Can You Install a Metal Roof Over Shingles in Wisconsin? Here’s What to Know
If your asphalt shingle roof is aging and you're considering switching to metal, you might be wondering: Can you install a metal roof over shingles in Wisconsin? The short answer is yes—in many cases, it's possible. But like most construction decisions, it depends on several key factors. In this post, we’ll walk you through the pros, cons, and local considerations so you can make the right decision for your home or business.
Why Homeowners Are Switching to Metal Roofing
Metal roofing continues to gain popularity among Wisconsin homeowners—and it’s not just about looks. Many of our clients are choosing metal as a long-term solution for protecting their homes, garages, and even detached shops. Whether you’re planning a full roof replacement or building a new garage or workshop, here’s why metal might be the smartest choice.
Long-Term Value
A professionally installed metal roof can last 40 to 70 years—far outlasting standard asphalt shingles. For homeowners looking to invest in their property for the long haul, that level of longevity is hard to beat.
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- Fewer replacements over your home’s lifetime
- Strong resale appeal, especially on updated homes
- Excellent pairing with long-term upgrades like siding replacement or energy-efficient windows and doors
Superior Weather Performance
Wisconsin sees everything from heavy snow and freezing rain to summer windstorms—and metal roofing stands up to all of it.
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- Sheds snow quickly to reduce ice damming
- Resists high winds and hail impacts better than most roofing types
- Doesn’t absorb moisture, reducing the risk of mold, rot, or warping
This makes metal a great fit for both residential re-roofing and new structures like custom garage builds or pole barns.
Lower Maintenance Needs
Once it’s installed, a metal roof requires very little upkeep. It won’t split, crack, or grow moss the way shingles can—and it holds its appearance for decades without constant repairs.
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- No need for frequent inspections or patching
- Won’t curl, warp, or disintegrate over time
- Pairs well with gutter installations and exterior remodeling projects
Energy Efficiency
Thanks to its reflective properties, metal roofing helps regulate indoor temperatures by deflecting sunlight during warmer months. In a climate like Wisconsin’s—with hot summers and cold winters—this can translate to noticeable energy savings year-round.
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- Helps reduce cooling costs in summer
- Can improve the performance of insulation and attic ventilation
- Complements other energy-efficient upgrades like attic renovations or basement finishing
Aesthetic and Functional Versatility
Metal roofing isn’t just practical—it’s also available in a wide range of colors and styles, from traditional standing seam panels to textured, shingle-look options.
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- Modern curb appeal with classic durability
- Suitable for both urban and rural homes
- Looks great when paired with custom decks, garage additions, and complete home renovations
Yes, You Can Install Over Shingles—But Not Always
In many parts of Wisconsin, it’s perfectly legal—and often practical—to install a metal roof over existing asphalt shingles. But that doesn’t mean it’s always the right solution for every home. Whether or not you can go this route depends on a combination of building codes, roof condition, and structural soundness. Here’s what you need to know before moving forward.
1. The condition of your existing roof matters
Not all shingle roofs are suitable for a metal overlay. If your current roof is severely worn, curled, or missing shingles in key areas, simply covering it won’t solve the underlying issues.
Before we recommend installing over shingles, Brad’s Construction conducts a full evaluation of your existing roofing system. We check for:
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- Excessive wear or curling
- Water damage beneath the shingle layer
- Soft spots or signs of rot
- Uneven surfaces that could prevent proper fastening
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If your roof deck or structural components are compromised, we’ll likely recommend a full roof replacement instead. It’s a more permanent solution and ensures your new metal roof will perform as intended for decades.
2. Know your local building codes
Wisconsin building codes generally allow one layer of roofing to be installed over another, but there are restrictions:
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- No more than two total layers (including the new metal roof)
- The existing roof must be properly fastened and free of loose or broken shingles
- Your contractor must verify that ventilation and flashing will still function correctly
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Permitting and compliance vary by municipality, so it’s critical to work with a licensed contractor who understands the requirements in your town. At Brad’s Construction, we handle the permit process from start to finish for homeowners in Winnebago County, Dodge County, and Outagamie County, ensuring everything is up to code before installation begins.
3. Structural integrity is non-negotiable
Metal roofing is lighter than most people expect, but that doesn’t mean it can go on just any roof. Your structure needs to be able to support the additional layer safely.
We thoroughly inspect:
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- Rafters and trusses for sagging or damage
- The roof deck for signs of rot or delamination
- Attic ventilation to ensure compatibility with a new metal system
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If repairs or reinforcements are needed, we’ll let you know—and we can handle the work in-house as part of our general contracting services. This integrated approach gives you a stronger roof and peace of mind.
4. Installation methods: direct vs. strapping system
There are two common ways to install metal roofing over shingles, and the right one depends on your roof’s condition and your goals:
Direct-to-deck installation
In this method, metal panels are fastened directly to the shingle layer. This is only recommended when the existing roof is smooth, flat, and free of damage. It's a faster, more affordable option—but it may trap heat and moisture if not vented properly.
Strapping or purlin system
With this approach, horizontal wooden battens (called purlins) are installed over the shingles to create a secure, level base for the new metal panels. This method offers:
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- Better air circulation under the roof
- Reduced risk of condensation and mold
- A straighter, more stable foundation—especially useful on older or uneven roofs
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Because of Wisconsin’s changing weather and freeze-thaw cycles, we often recommend the strapping method for homeowners looking to maximize roof life and energy efficiency.
Benefits of Installing Metal Over Shingles
When done properly, installing a metal roof over existing shingles can be a smart and cost-effective solution for many Wisconsin homeowners. While it's not the right approach for every roof, there are several advantages worth considering if your home qualifies.
Lower overall cost
One of the biggest benefits is the savings on labor and disposal. Tearing off an old shingle roof adds time, crew hours, and landfill fees. By skipping that step, you're often able to:
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- Reduce total project costs by several hundred to several thousand dollars
- Avoid unexpected surprises hidden beneath the shingles
- Allocate more of your budget toward premium metal materials or roof enhancements
This can be especially valuable if you're also investing in other home upgrades, such as garage construction or exterior renovations, and want to make the most of your remodeling dollars.
Quicker project timelines
With the tear-off eliminated, metal-over-shingle installations often take less time from start to finish. That means:
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- Less disruption to your daily routine
- Faster protection from future storms
- A quicker path to curb appeal and peace of mind
This efficiency can be especially helpful if you're coordinating multiple projects at once—like adding a new shop or outbuilding, or preparing your home for sale.
Added thermal buffer
Although not a substitute for proper insulation or attic ventilation, your existing shingle layer can act as a buffer zone beneath the metal panels. This may help:
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- Reduce heat loss during the winter
- Dampen outside noise, such as hail or heavy rain
- Improve overall roof performance when combined with attic improvements or window replacements
Eco-conscious option
Leaving the shingles in place keeps hundreds (or thousands) of pounds of roofing material out of landfills. For homeowners focused on sustainability, this can be a more environmentally responsible route—especially when paired with a metal roof, which is often made from recycled materials and fully recyclable at the end of its life.
Of course, not every roof is a good fit for this method. If your current shingles are severely damaged, or if your decking has moisture issues or structural concerns, a full roof replacement may be the better long-term investment. At Brad’s Construction, we’ll never push a one-size-fits-all solution. Our team always provides honest recommendations based on what’s best for your home, your safety, and your budget.
Real Example: A Metal Roof Upgrade in Oshkosh
One of our clients in Oshkosh contacted us about a leaking asphalt roof that had seen better days. After a thorough inspection, we confirmed that the shingles were worn but still structurally sound. We recommended a strapping system for proper ventilation and installed a standing seam metal roof over top.
The result? The homeowner now has a stunning, low-maintenance roof that handles Wisconsin’s snow loads with ease. Plus, the added curb appeal and energy savings were immediate bonuses.
Why Work with Brad’s Construction?
At Brad’s Construction, we’ve completed dozens of metal roofing projects across Winnebago County and neighboring areas. We offer:
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- Experienced roof inspections and accurate, honest estimates
- Metal roofing installation over shingles or full tear-off options
- Garage and shop building services for clients upgrading their properties
- High-quality craftsmanship and clear communication from start to finish
Proudly Serving Southeast Wisconsin
We provide metal roof installation and general construction services throughout:
Ready for a Roof That Lasts Decades?
If you're considering metal roofing in Wisconsin, we’re here to help. Whether your home is in Oshkosh, Fond du Lac, or the countryside near Mayville, we’ll assess your current roof and give you expert recommendations tailored to your needs and budget.
Call Brad’s Construction today to schedule your estimate or learn more about whether installing metal over shingles is right for you. We’re your trusted partner for roofing, remodeling, and garage/shop construction across Southeast Wisconsin.
