Among the many types of metal roofs, copper is one of the best materials with a long history. The distinctive look of this soft yet durable metal attracts the attention of many homeowners. But the high price tag can scare just as many away. Is copper roofing worth the costs?
Copper - The Oldest Type of Roofing
Copper is one of the oldest forms of metal roofing, appearing on buildings constructed as far back as 300 BC, such as the Sri Lankan Loha Maha Paya Temple - Mahamuni Buddha Temple.
In Europe, you can witness copper on other antique buildings of importance. Like Hildesheim - St. Mary's Cathedral - which features a copper roof dating back to 1280 AD, making the roof 734 years old!
Hildesheim - St. Mary's Cathedral
Copper roofing isn't just present in old-world countries throughout Europe. You can also see plenty of early homes and important public buildings from the Revolutionary War with the signature blue-green brown patina of copper roofs throughout the US, such as the Capitol buildings.
Copper Roof Patina Process: Do All Copper Roofs Turn Green?
Copper roofs start out a brassy shiny orange color, like a new penny. But over time, the material starts to turn a bluish-green, like the Statue of Liberty. Does this mean your roof is decaying?
Absolutely not! The patina can be the copper roof's protective surface.
This discoloration - referred to as a patina - is a natural chemical reaction - oxidation. As copper and oxygen interact, it forms Cu2(OH)2CO3 - the cause of the patina's colors. When sulfur from the air interacts with the copper surface, it can create copper sulfide, which can cause black streaks.
Rather than causing damage to the copper, as rust does to iron, the corrosion - patina - forms a thin protective layer over the top of the copper, protecting the inner layers from corroding, which is bad.
It can take years for your roof to finally develop the lovely green patina. But changes start as soon as a few days after install. At first, the copper will turn a dull brown. Then it begins to get the blue-green tint as the patina layer thickens; there may also be some streaks of black or turquoise.
Factors that can affect the time it takes a copper roof to form a full patina include:
- Cleanliness of the copper - oxidation may slow if there were lubricants used during manufacturing.
- Environment - patinas form faster in areas with air contaminants and moisture but take longer in climates that are dry and have cleaner air.
Can you stop a copper roof from forming a patina?
There are ways to speed the process up, like using a saltwater bath to start the natural tarnish or using an acid wash to force the green patina. In dry climates, where it can take up to twenty years for a patina to form, an artificial aging solution might be preferred, as you see results in as soon as 24 to 48 hours after treatment.
You can use a soft bristle brush and a solution of salt and vinegar to clean your roof without damaging the patina, but copper is low maintenance and rarely needs upkeep.
Pros of Copper Roof
Copper roofs have multiple benefits, explaining why this material repeatedly appears on important buildings and homes worldwide.
Copper Roof Can Increase Resale Value due to Aesthetic Appeal.
The unique look is the most significant selling feature. Starting as a lovely shiny orange, copper eventually turns dull brown and then the signature blue-green as the patina forms. This timeless look matches a wide variety of architectural styles.
Did you know?: The Statue of Liberty is made of copper. She's the perfect example of how copper ages after hundreds of years. In her year of birth, Lady Liberty was as shiny as a new penny. However, years of exposure to the elements and the sea have transformed her into the beautiful blue-green shade we admire today.
Copper's Durability Can Extend Your Roof's Lifespan to Almost a Century.
Copper roofs are durable, with a 70-100 years lifetime. No other material features the unique traits of copper, which improves with age rather than degrading. No matter the type of abuse your copper roof experiences, it won't damage. As a result, as copper ages, it builds up a protective film that creates a shield over the roof surface.
Copper Roof is Energy-Efficient and One of the Most Sustainable Roofing.
Copper is completely sustainable because it's made of all-natural materials, largely copper that's been recycled. And because it's recyclable and long-lasting, there's less waste going into landfills or mined from the Earth.
Copper Roofs Require Little Maintenance.
Copper roofs are virtually maintenance-free. Once your roof is on your house, there's nothing for you to do but enjoy its beauty and all the compliments you'll get from visitors. Of course, you can clean your roof and freshen it up over time if you desire, but it's purely a personal choice and isn't necessary for the performance of your roof. Copper roofs need no painting or coating and will not rust.
Copper Roof is Cost-Efficient.
Copper comes with a high price tag for the purchase of the materials and installation. But you'll recoup these costs over time. By installing one roof a century versus replacing your roof every few decades, you'll save thousands of dollars during your home's ownership. You'll also see savings in energy bills
Copper Roof is Strong Enough to Withstand Harsh Weather Conditions.
Copper roofing is the perfect choice for climates with severe weather, like high winds, torrential rains, and heavy snow.
Copper Roof is Resistant to Corrosion.
As copper develops the patina, it forms a protective layer that blocks the copper beneath the surface from corroding. This patina acts as a barrier against water, wind, impacts, and insects.
Copper Roof is Fire-Resistant and Prevents the Spread of Fire.
Fire is a crucial danger for which you need the best protection, such as a Class A fire rating. Due to copper's high heat threshold, your roof gets the most protection from distorting, destruction, or spreading fire to other structures.
Copper Roof is Naturally Insects-, Mildew- and Fungus-Resistant.
Copper contains antimicrobial qualities. Whether it's uncoated or copper alloys, the organisms make the copper naturally able to resist bacteria growth and fungus. You'll never have to worry about algae, moss, mildew, or rotting.
Copper Roof is Lightweight and Does Not Stress the Roof Structure.
Copper roofs are lighter in weight than other roofing types. More lightweight materials put less strain on a top, while too much weight can cause roof strain. Copper's lighter weight allows contractors to install rafters and trusses, reducing installation costs and increasing the roofing components' lifespan.
The Flexibility of Copper Allows It to Be Shaped to Fit Unique Architecturals.
Copper is a softer metal, allowing it to bend or mold into odd angles and shapes. You'll often see this material used for accent pieces due to its ability to shape into various forms without causing damage.
Copper Roof is Environmentally-Friendly.
The ability to reflect heat rather than absorbing it makes copper excellent for reducing your energy bills by requiring less use of electricity or gas to control your home's internal temperature. And copper's high recyclability means it will get repurposed into something new rather than tossed in the trash.
Cons of Copper Roof
Copper Roofs Cost More Upfront Than Other Roofs.
There is no doubt that copper is one of the most expensive materials. Installing a complete copper roof costs about four times as much as an asphalt roof. But between the high ROI, low maintenance, and extended lifespan, many people feel the cost is worth it. It can also be seen as an investment.
Copper Roofs May Have Noise Problems.
Copper is a softer metal, so if your contractor doesn't use the proper insulation, noises like rain, hail, or falling debris can sound much louder inside. Therefore, it's crucial to use a sound-dampener like an existing layer of shingles, solid sheathing, or plywood sheets.
Copper Roofs Have Higher Requirements For Installation.
Installing copper roofing requires different installations than other metal roofs or materials like asphalt shingles. It also requires specialized tools like power seamers or power pan formers.
Copper Will Be Incompatible With Other Metals.
If copper comes into contact with incompatible metals, it becomes very corrosive - galvanic corrosion. You cannot use zinc, aluminum, or steel around the copper roofing.
Copper Expands or Contracts in Response to Temperature Fluctuations.
As the temperature changes, copper will contract and expand. This movement of the material can cause the fasteners holding the pieces in place to become loose, which requires repairs.
Copper Roofs Will Never Be Able to Maintain Its Original Color.
Copper doesn't retain its glorious, shiny copper color. Over time and weather exposure, the copper goes through a natural process that causes the material to turn colors.
As the copper comes in contact with rain, sun, and atmospheric pollutants, it builds up an oxide-sulfate patina layer that appears brown, blue-green, or black. This process can take years and depends on multiple factors, including areas with a pH lower than 5.5, which speeds up the aging process.
Types of Copper Roof
Copper roofs have limited options compared to other roofing materials. But each type of copper roof has a unique design and installation.
Continuous Copper Roofing
A continuous copper roofing is a specialty application that's prefabricated for each job. The assembly and installation require laying copper sheets on top of the roofing substrate. Once the installation is complete, the copper sheets form a solid piece without joints or seams.
Copper Roofing Panels
Another type of copper roofing consists of copper panels. This option is cheaper than continuous roofing, mainly because it has seams. A copper panel roof consists of standard width sheets of copper that are hand-installed and form visible seams, either crimped - a standard seam copper roofing - or welded or brazed onsite.
Copper Roofing Shingles
Copper shingles are a popular choice due to the low cost, even though it requires the installers to hand-apply the pieces. However, care must be used to prevent damaging the copper's soft surface. It also involves the use of copper fasteners. Using other types of metal on copper causes metallurgical reactions.
Copper Roof Cost Per Square (Shingles and Panels)
Copper roofs do come with a high cost for materials and installation compared to other roofing materials. But investing in a copper roof can result in an 85.9% ROI (return-on-investment). You can also see lower insurance rates in many states throughout the US, including California and Texas, where there's a severe threat of wildfires.
You can expect to spend between $11 and $15 a square foot for a copper roof. For a roofing square - 100 square feet - you'll pay $1,100 to $1,500 for materials and installation. So, a single-story 1,800 square foot house can cost anywhere from $25,051 to $37,577.
The type of copper roofing can also affect the final price for materials. The cheapest choice is shingles, which run from $10 to $16 a square foot, or copper tiles, which can cost between $12 and $15. Roof panels can cost between $15 and $18, while standing seam runs $16 to $22 a square foot.
Copper vs. Other Metal Roofings
Copper vs Aluminum
Aluminum is one of the top choices for metal roofing and shares some similarities with copper. They have a lot in common. Both materials are higher priced - aluminum costs more than steel, but copper is the highest. And they are lightweight, resistant to rust. and both have high energy efficiency due to their reflectivity.
They also have differences. You can find aluminum in multiple color paints, whereas copper only comes in its natural color until it turns green over the years through the patina process.
Copper vs Zinc
Zinc is another durable material that tarnishes produced by oxidation or other chemical processes like copper. The fantastic thing is that this patina helps the zinc heal itself from damage over time. But unlike copper, which creates a lovely change of colors, zinc tends to become chalky as it turns into a blue/gray from water exposure, which is aesthetically displeasing to many. Zinc can also be more prone to damages from impacts and hail since it's a softer metal.
Copper vs Steel
Steel has an advantage over copper for being more economical - cheaper. Both copper and steel are strong, but copper will never rust due to the patina chemical reaction, whereas steel will rust when exposed to water. But steel can get a coating that protects it from the elements. Zinc is typically used; steel needs a recoating every ten to twenty years, whereas copper never needs a protective coating.
Copper Roof's Possible Problems
Copper roofing doesn't have many issues to worry about since it's a durable material that can outlast the structure it protects. That said, two concerns may apply to you if you pick a copper roof.
Patina is A Slow Process.
The first issue is the length of time it can take a roof to patina or change colors. It can be as fast as two years or take up to twenty years in some conditions. See our section on how to get a patina look without the wait to learn how to speed up the color-changing process.
Galvanic Corrosion Might Occur.
The second problem that can occur with copper roofs is the potential for electrolytic corrosion or galvanic corrosion. This chemical reaction can occur when two dissimilar metals touch, followed by contact with an electrolyte (water).
This reaction can cause your roof to corrode at different rates for an uneven patina with potentially damaged spots that may need repairs.
Is Copper Roof A Good Choice For Your Roof?
At this point, you may be trying to decide if a copper roof is a suitable choice for your home. If you answer yes to any of the below criteria, you may be on the right track choosing copper over other roofing materials.
Can You Afford It?
One of the first things you should ask yourself when debating on a copper roof is can you afford the huge upfront expense? If it's out of your budget, start your conversion using copper accents like flashing and covering windows and main doors, turrets, or dormers.
Is It Your Forever Home?
Although you get a great ROI on copper roofs, most people will not want to spend a large sum to install copper roofing on the house they plan to sell. Therefore, copper roofs are best for homes that you plan to live in for a long time.
Do You Live in a Climate With Extreme Weather?
Copper is superior to other roofing materials due to its durability. No matter the weather conditions in your location, a copper roof has a higher chance of surviving without any damages. It can handle severe amounts of rain, snow, and even hurricane-force winds and tornadoes. And copper is also excellent for marine settings due to its imperviousness to saltwater.
Red alert!: Be aware that climates with excessive rain, wind, and humidity (plus saltwater conditions) will cause the roof to patina faster than roofs in mild climates.
Do You Like the Patina Look?
If your goal for picking a copper roof is to have a beautiful shiny color, you're out of luck. The patina process that copper goes through is a natural chemical reaction solely to protect the copper from corroding. So if you don't like the hints of blue, green, brown, black, and turquoise in random patterns, you might not want to choose copper as your roofing. Instead, go with metal painted in a copper color - these never patina.
Final Verdict
Copper roofing is a superb choice for roofing due to its superior performance, distinctive look, and outstanding lifespan. Once you invest the money to install a copper roof, there will not be a need for you to repair or replace your roof again in your lifetime. But if you're looking for a roof that doesn't patina, you'll need to figure out different roofing material.