Updated 2/1/2026
Can a metal roof be installed over shingles? What causes a metal roof to leak or look uneven?
These are common questions we hear from homeowners across Indiana and Michigan.
At Equity Roofing, we’ve installed hundreds of metal roofs in this region, from farmhouses to modern homes. Our crews are trained specifically on standing seam and exposed fastener systems, so we know exactly where most mistakes happen, and how to avoid them.
In this guide, we’ll walk you through the exact process of installing a metal roof, what layers are critical for long-term durability, and the red flags to watch out for before signing a contract. If you want a roof that performs for decades—not just looks good on day one—this article will give you the confidence to ask better questions and make the right decision.
Homeowners most often choose between two systems.
An exposed fastener roof is a type of metal roofing system where the screws that hold the metal panels in place are visible on the surface of the roof. You’ll often hear these called screw-down metal roofs or corrugated metal roofs.
These can be paired with Pro-Z fasteners, a higher-quality screw designed specifically for exposed fastener metal roofing. It’s still an exposed fastener system, but with upgraded components meant to reduce common failure points.
Compared to standard roofing screws, Pro-Z fasteners typically offer:
In short, they’re designed to slow down the most common leak issues seen with exposed fastener roofs. We discuss them more in our article, What Are Pro-Z Fasteners (and Are They Worth It?)
A standing-seam metal roof is a premium metal roofing system in which the panels lock together vertically, with all fasteners hidden beneath the metal seams rather than exposed on the surface.
They’re often chosen for their long life span, minimal maintenance requirements, and superior leak resistance.
In many homes, a metal roof can be installed over existing shingles if the roof meets specific conditions.
To qualify for a metal roof overlay, the shingle roof must have:
If those conditions are met, installing metal over shingles reduces mess and eliminates the need for a tear-off. However, cedar shake roofs typically require full removal before metal can be installed.
Some homeowners expect that installing metal will fix dips or uneven areas in their roof. If the unevenness is caused by framing issues in the house itself, the metal roof will follow that same line. Fixing a structural dip requires separate work.
A quality metal roof installation includes furring strips, a vapor barrier, and ventilation components. Skipping these steps is one of the most common causes of long-term problems.
The table below explains why each layer matters and what can happen if it is skipped.
| Installation Layer | What It Does |
| Furring strips | Used for exposed fastener panels for secure screw attachment and airflow |
| Vapor barrier / underlayment | Protects wood from condensation |
| Ventilation components | Removes heat and humidity |
Indiana and Michigan experience big temperature swings throughout the year. In summer, warm, humid air meets the cool underside of a metal roof. This causes condensation, similar to how a cold soda can sweat when you take it out of the refrigerator.
Without proper protection, that moisture can rot furring strips and other wood components, or even cause mold in the attic. A vapor barrier stops moisture from reaching the wood. Ventilation allows air to carry away any humidity that gets in. Together, these elements keep the roof system dry year-round.
Oil canning happens when flat metal panels reflect light unevenly due to uneven surfaces underneath or improper installation. While it cannot be eliminated completely, it can be reduced by:
Many oil canning issues come from installing metal directly over shingles without furring strips.
Most residential metal roof installations can be completed within two to four days, but more complex roofs may take longer. Likewise, simple jobs can be completed in as little as one day.
Complex roofs are those with multiple angles, valleys, and other features. Panels must be cut and fitted around obstacles, increasing labor and material costs. On simpler roofs, seamless panels run from ridge to edge without interruption.
Homeowners can stay in their homes during their roof installation. A few simple preparation steps help the job go smoothly.
Keep pets and children indoors and away from work areas whenever possible. Crews can coordinate breaks if a pet needs to go outside or if you need to leave the house. Make sure to clear your driveways or access points before the crew arrives so they can begin work promptly!
Most long-term problems with metal roofs can be traced to shortcuts during installation.
Installation shortcuts include:
Once the metal roof installation is done, it should go through a final inspection. The contractor should check:
By the time you’re reviewing a metal roof contract, you’ve likely already compared materials and pricing. At this stage, the more important question becomes who is installing your roof and how they plan to do the work.
Before signing anything, homeowners should be able to get clear, confident answers to the questions below.
| Question | Why It Matters |
| Is the contractor licensed? | Confirms the contractor meets state and local requirements and provides accountability if issues arise |
| Do you offer a workmanship warranty? | Protects you if problems occur due to installation, not material defects |
| How much experience do you have with metal roofing? | Metal roofing requires different tools, techniques, and detailing than shingles |
| Can you show past metal roof installations? | Allows you to verify workmanship quality and see similar completed projects |
| What fasteners do you use? | Low-quality fasteners are one of the most common causes of leaks over time |
Asking these questions helps homeowners spot red flags early. A qualified metal roofing contractor should be able to explain their process, materials, and experience without hesitation.
This approach shifts the focus away from price alone and toward long-term performance—where metal roofing truly proves its value.
At the end of the day, even the highest-quality metal roofing system will fail if it’s installed incorrectly. This is especially true in Indiana and Michigan, where harsh seasonal changes make proper ventilation, underlayment, and fasteners non-negotiable.
Now that you know what a correct installation looks like, the next step is to make sure your contractor follows it. Use this guide to spot red flags, ask smarter questions, and demand the kind of craftsmanship your investment deserves.
Your next step is to review our cost comparison guide for standing-seam and exposed-fastener metal roofs to help you decide which is best suited to your home.
At Equity Roofing, we don’t cut corners for any roof, be it metal or shingle. From underlayment to fasteners, our crews are trained to install metal the right way the first time. If you’re ready for a roof that performs for decades, we’re ready to help.