Choosing The Best Metal Roof For Your Home Or Business – Everything You Need To Know
It’s time to replace the asphalt shingles on your roof. You’ve heard metal is a good option for an alternative roofing material. However, you don’t want to blunder into a misinformed decision and spend years regretting a mistake.
If this describes you, don’t worry. We get it.
At K. Graber Construction, we want to help you understand the ins and outs of metal roofing so you can make an informed decision about the roofing material that’s best for you.
We’ll explore different kinds of metal roofs, as well as different styles of metal roofs. Before we finish, we’ll make sure to compare metal roofing with other types of roofing so you can get a big picture view of what’s at stake.
Let’s get started!
4 Main Types Of Metal Roofing
It’s important to understand that a metal roof doesn’t describe a specific product, but rather an entire range of products.
When you say, “I want a metal roof,” you aren’t limiting yourself to one kind of roof. You are opening up a world of opportunity!
After all, there’s more than one kind of metal.
Let’s take a look at each of the popular materials used to create metal roofs and the pros and cons of each.
Copper roofing has been used for centuries around the world. Copper is an extremely durable metal, and in ideal environments, lasts well over 200 years.
In fact, you may recognize some famous historical structures that have copper roofs.
Belvedere Palace in Vienna, Austria, and Berlin Cathedral Church in Berlin, Germany, are both exquisite buildings that display copper roofs.
But if you look at these roofs, you’ll notice that they have a beautiful green color instead of the shiny, bronze color normally associated with copper.
Why does copper change color?
Copper naturally turns green over time as it reacts with oxygen in the air – a chemical reaction known as oxidation.
The green color is simply the natural shade of the patina that forms over the copper surface. The patina protects the copper from deterioration and creates a light bluish-green color, which is seen on many copper rooftops and structures.
It’s this green patina that protects copper and makes it one of the most long-lasting roofing materials you can find.
Copper has a few downsides, though.
For one, it’s a soft metal, which means that it is easily dented by debris and hail. Copper also tends to expand and contract with swings in temperature, which can cause maintenance issues.
And the million-dollar question? Yes, copper is more expensive than most roofing materials. Depending on your needs, it may be more than you need to get the job done.
The strength of aluminum roofing lies in its ability to resist corrosion.
When the outer layer of aluminum reacts with oxygen, it creates a layer of aluminum oxide that protects the inner layers of metal from corrosion.
This ability to resist corrosion makes aluminum a great choice of roofing material in coastal areas. However, aluminum's natural patina is not considered aesthetically pleasing, so it is usually painted.
Like copper, aluminum’s downside often comes down to cost. As a commodity, aluminum’s price range fluctuates depending on the market. Typically, the price of this metal is somewhere between steel and copper.
Because of its price, aluminum is often used in much thinner thicknesses than steel. That means that if you’re located in a region with high winds, hail, or severe inclement weather, aluminum may not be the choice for you.
If you want the anti-corrosive properties of aluminum, but need something a little sturdier, you might consider installing a steel roof and then applying an aluminum roof coating.
Zinc is an amazing metal that uses its patina to heal its scratches and stay strong for over 100 years.
Zinc is considered a “green” metal since the energy required for processing zinc is so low.
Zinc is also 100% recyclable and available in most local markets.
However, zinc has two main downsides.
First, zinc is not particularly aesthetically pleasing. Like most bare metals, zinc forms its own natural patina - this patina is a bluish, gray color. It’s not the patina itself that’s problematic, though.
When water flows on chalk roofs, a little residue remains. This chalking effect doesn’t look good.
Second, zinc is not cheap. In fact, zinc is often comparable to copper, one of the most expensive roofing materials.
When you think of a metal roof, you most likely think of a steel roof.
Because steel is the most commonly used material when it comes to metal roofing.
Steel is not an actual metal. It’s an alloy made from iron and other elements. However, it is still counted under the category of metal roofing.
Steel is very sturdy and quite resistant to inclement weather. On average, a steel roof lasts at least 50-70 years.
Like zinc, steel is also considered a green material since it can be recycled. And, when compared to other materials, steel is the least expensive. This makes steel both affordable and available in greater quantities than the other metals on this list.
Because steel is not a bare metal, it does not create its own natural patina. That means steel is susceptible to rusting. However, when painted and coated with a PVDF roof coating, steel lasts for years without rusting.
Since steel is such a common roofing material, it is worth knowing the three major subtypes of steel roofing. You are more likely to decide between these three subtypes of steel than between the major types of metals.
- Galvanized Steel is created by using a layer of zinc to protect an inner layer of steel from corrosion. This is the most common form of steel roofing material.
- Galvalume Steel is similar to galvanized steel, but rather than using only zinc for its protective coating, it uses a combination of aluminum and zinc. This offers better surface protection than galvanized steel.
- Weathering Steel is heavy steel, designed for use in tough industries like bridge construction. It is designed to intentionally rust, protecting the inner layer of steel. Weathering steel is often used in accent roofs with the understanding that regular maintenance will be needed.
Main Styles Of Metal Roofing
Once you’ve chosen a metal for your new roof, you’ll need to select a style of roof. While the style options for metal roofing are endless, breaking them down into three main categories is helpful.
Standing seam metal roofing (hidden fastener)
Corrugated metal roofing (exposed fastener)
Interlocking modular metal panel roofing
Standing Seam Metal Roofing
Every roof has to be fastened to the roof deck in one way or another. Asphalt shingles, for example, are nailed to the roof deck.
Metal roofs are screwed to the roof deck instead of nailed to the roof deck. However, there are two significant differences in the way metal roofs are screwed to the roof deck.
Pros of Standing Seam Metal
Hidden fastener metal roofing, typically called standing seam metal roofing, snaps together and hides the fastening system from view.
Since all the fasteners are hidden beneath the metal roof itself, they are also unlikely to leak.
That’s a big deal!
After all, a leaking roof isn’t doing its job. Even though metal roofs are incredibly durable, a lot of care still needs to be taken to make sure they don’t leak. A standing seam metal roof is very unlikely to leak at all.
Because standing seam is so watertight, it can be used on lower roof pitches than other metal roofing styles. While most metal roofing styles can’t be used on a roof pitch under 3/12, standing seam can be used the whole way down to 1/12.
And there’s a lot more to like about standing seam metal than just the fastening system!
Standing seam is considered a premium metal roofing. That means it is usually made from thicker metal and finished with the best PVDF paint system.
Standing seam metal is also custom made for your project. Contractors that install standing seam roofs have a machine that takes large rolls of metal and bends the metal to use the snap-lock system you want. It also fabricates the sheets of metal to the exact length needed for your project.
While other metal roof styles don’t work with all the types of metal roofing discussed earlier in this article (copper, zinc, aluminum, steel), standing seam does.
Another perk of standing seam roofs is that the fastener system used allows the metal to expand vertically.
Why is this a big deal?
Other styles of metal roofing that fasten directly to the roof deck do not have this capability. That means that when the weather gets hot, and the metal starts to heave and buckle. In some scenarios, this can cause the screws that hold down the metal to begin to loosen, allowing water to seep in around them.
Cons of Standing Seam
Standing seam isn’t the best option in every category, though.
One downside of standing seam metal roofs is that they take a long time to install. Each piece of metal is manufactured on the job site. The individual pieces of metal are also much skinnier than other styles of metal roofing. (Standing seam is usually 12-18 inches wide, while other styles are around 3 feet wide.)
Not only that, but a standing seam metal roof is simply more challenging to install. If you want a standing seam roof, it’s time to call in a professional. Don’t try this one by yourself.
Because standing seam is a premium material and takes skill and time to install, it is more expensive than most metal roofing styles. An estimated cost of a standing seam metal roof is $8-$14 per square foot compared to $5-$8 per square foot for other styles.
When to Use Standing Seam Metal
So, how do you know if standing seam metal is for you?
If you have the budget to afford it, standing seam is a great option. It’s high quality and lasts a lifetime. While it’s on your roof, it needs very little maintenance.
Standing seam is also the best option for roofs that have very shallow pitches.
If you want to use an exotic metal like copper, zinc, or aluminum, standing seam is probably the best option, since other styles of metal roofs don’t commonly offer these options.
Exposed Fastener Roofing
The second style of metal roofing is exposed fastener roofing. As the name suggests, the main difference in this roofing style is that the metal is attached to the roof with exposed screws.
But there’s a lot more to this roofing system than a fastening system. Let’s take a look at the pros and cons that exposed fastener systems bring to the table.
Pros of Exposed Fastener Systems
There are a few big ways in which exposed fastener roofing systems outperform standing seam.
First of all, exposed fastener systems are straightforward to install. Metal panels for exposed fastener roofing systems come pre-manufactured and can be picked up at most hardware stores. All you have to do is screw them to your roof.
Like we mentioned earlier, the metal panels for exposed fastener systems are often at least twice as wide as standing seam panels. There are also fewer trim pieces like ridge capping on an exposed fastener roof.
Since less material is needed, and since installation is much easier on exposed fastener roofing systems, the cost is less than standing seam roofs.
Exposed fastener panels are stronger than standing seam panels, so they are much better for applications in which you span from purlin to purlin.
Cons of Exposed Fastener Systems
Though exposed fastener systems outperform standing seam in terms of cost, standing seam is usually considered superior.
Because of the fastening system.
With exposed fasteners, each screw creates a hole in the metal and a potential leak spot.
The screws are equipped with a rubber washer that usually keeps the hole watertight. However, if the screw is overtightened or under tightened, water seeps in around the washer. On a roof with thousands of screws, it’s relatively likely that at least one of them will begin leaking over time.
With exposed fastener systems, the metal panels are screwed directly to the roof deck, which means the panels can expand and contract with the weather. At times the heaving metal panels will cause a screw to loosen and allow water seepage.
Another downside of exposed fastener systems is that they are less flexible when it comes to the types of materials that can be used.
Since the metal panels often have a screw running through a rib, softer metals like copper and zinc aren’t great options. In exposed fastener systems, steel is almost exclusively used.
And finally, exposed fastener systems can’t be used on roof pitches less than 3/12.
When to Use Exposed Fastener Systems
So, when is an exposed fastener metal roof the right choice?
If you want a metal roof, but your budget doesn’t allow for standing seam, an exposed fastener metal roof is a great option.
If you prefer to do your own roofing work, exposed fastener metal roofs are the way to go. They are much easier to install!
And lastly, if you need to span spaces between purlins on a pole barn type structure, exposed fastener panels are better than standing seam panels.
Interlocking Modular Panel Metal Roofing
Interlocking modular panel metal roofing is a metal roofing system created to replicate different styles of roofs.
They take the key concepts from standing seam metal and make a few fundamental changes.
Pros of Interlocking modular panels
Just like standing seam, interlocking modular panels utilize a hidden fastener system. They are also very similar to standing seam roofs in terms of cost.
Unlike standing seam, which is run vertically up and down the roof, these interlocking panels come in small squares and are run in courses horizontally across the roof. (Like asphalt shingles).
The panels interlock with each other on all four sides and are incredibly watertight.
The real value of this roofing system is its aesthetics.
The metal panels are stamped or coated to replicate other roofing styles. For example, you could get metal stamped to look like slate, tile, or wooden shakes. You can even get stone coated metal to look like asphalt shingles.
Because the metal panels have so much texture and ribbing, they can often be placed directly over an old roofing system.
Cons of Interlocking Modular Panels
The cons of interlocking modular panels line up closely with those of standing seam systems.
They are expensive and time-intensive to install.
Another con of interlocking modular panels is that they are not recommended to be installed on a roof with a less than 3/12 pitch.
When to Use Interlocking Modular Panels
If you want a metal roof's durability, but don't like the ribbed look of standing seam and corrugated metal, you should consider interlocking modular panels.
If you are doing a re-roofing project (rather than a new construction project), you might consider interlocking modular panels. They can often be installed directly over the old roof since the panels’ texture hides swells you may see in the old roof.
Saving the labor of tearing off an old roof may help regain some of the extra money it takes to install interlocking modular panels.
5 Benefits Of Metal Roofing
Maybe after all of this reading, you’re beginning to think it would be simpler to stick with asphalt shingles.
But are you sure you don’t want the benefits of a metal roof?
No matter which kind of metal roof you choose, it’s bound to be a superior product to asphalt shingles.
Just think about it. Metal roofs are:
- Durable and maintenance-free. They truly last a lifetime. Asphalt shingles usually last around 20 years
- Environmentally friendly. Metal roofs are often made from recycled material and are completely recyclable at the end of their lifespan.
- Fire-resistant. Metal is not nearly as flammable as asphalt shingles.
- Energy-efficient. Metal roofs reflect solar radiant heat, which can reduce cooling costs by 10-25%.
- Low weight. Per square foot, metal roofs are much lighter than shingles. This puts less strain on the structural integrity of your home.
The decision seems straightforward. Whether you’re building a new home or re-roofing your existing house, metal roofing is the way to go.
There’s a lot to consider when it comes to metal roofing, but now you have the knowledge to make a decision about the best kind of roof for you.
And remember, there’s nothing better than talking in person with your local metal roofing contractor!
If you are looking for a new metal roof, or want to replace your old roof and live in North or Central Indiana, contact us at K Graber Construction today. We offer both new home construction and remodeling, and we install the different products discussed in this article, such as metal roofing.
We work hard to be a trustworthy contractor, and we are more than happy to let you see our previous work or talk to former customers.
Contact us today to see how we can help with your metal roof. We look forward to meeting you!