Metal roofs are becoming a popular choice for both homes and outbuildings, such as sheds. The industry has expanded to meet the needs of potential owners, offering more color choices than were once available. They are known to be one of the longest-lasting types of roofing available and require little maintenance.
Tree and other debris can slide off metal roofing more easily than they can from shingles. Snow can also slide off more easily, keeping roofs from supporting a snow load for long periods of time.
How Long Will a Metal Roof Last?
Metal roofs can last for over 50 years with proper care. Compare that to the common asphalt shingles, which have an average lifespan of 10 to 20 years. Even the thicker architectural shingles only last up to 25 years.
While metal roofs do cost more in the beginning, the long life more than makes up for the initial cost. In addition, a metal roof will probably add to the resale value of a home when it’s time to move on, especially if any outbuildings such as storage sheds also are roofed in metal. Many people enjoy a discount on their homeowner’s insurance with a metal roof as well.
What Type of Metal Roof Lasts the Longest?
When thinking about how long metal roofs last, one must consider the various metals used in roofing. The five most common types of metal roofing are aluminum, steel, copper, zinc and tin.
* Steel – Steel is the most common metal roofing material.
Pros: Steel roofs last a long time. In fact, some galvanized steel roofs with specially designed paint systems come with 40 to 50-year warranties or lifetime warranties. Some steel roofs have lasted as long as 100 years. It’s resistant to fire, hail damage, and wind. Galvanized steel, which involves using a zinc coating, it’s more resistant to rust. Get more information on galvanized roofing in my article How to Install Galvanized Metal Roofing On a Shed.
Cons: Color options can be somewhat limited. Some people also just don’t like the look of the seamed or corrugated panels. It can be subject to rust, especially in areas that are very humid or have salt in the air from the ocean. Steel roofs are also not recommended for a do-it-yourself installation unless the owner has some experience with them.
Pros: This is the most lightweight of all the common roofing metals, and is easier to work with than most. It comes in many attractive colors. It’s very corrosion resistant. It’s a popular choice for people living near saltwater bodies, as the salt in the air won’t cause rust. The price is usually a bit less than for steel as well. Standing seam aluminum roofs usually last 50-80 years.
Cons: Aluminum roofing tends to dull over time, which some people find objectionable. It’s also more prone to show damage from hail or tree branches falling on it.
* Copper – This is a popular choice for metal roofing, especially in higher-end construction.
Pros: Copper makes the least sound of the metals when it is struck. This shouldn’t be a problem, as metal roofs of any type usually have sound-deadening materials installed underneath the metal. Most people choose copper for its appearance. It eventually sports a green patina.
This patina actually adds more protection against oxidation. Copper is also lighter weight than steel and is a bit easier to work with. The lesser weight also puts less strain on the roof supports. However, copper roofs are very resistant to various problems such as fire and dents. Standing seam copper roofs usually carry a warranty of 50 years or more but may last over 100 years.
Cons: Copper tends to expand and contract more than some other metals, which can cause the loosening of some fasteners. Homeowners need to hire installers who have experience with copper. Copper also tends to cost more than some other metal roofing choices.
* Zinc – Zinc is more popular in Europe, but is gaining fans in the U.S.
Pros: It has a unique appearance, forming an attractive patina, which also serves to prevent weathering and rust. It also resists fungus and mildew, along with insects and fire. It can last 80 to 100 years.
Cons: Zinc roofing can be hard to come by and is more expensive than steel or aluminum. The patina may not look uniform in color over the whole roof, which bothers some owners. Zinc should only be installed by somebody experienced with it.
* Tin – Tin roofing is actually a misnomer, as it’s not really made of tin. It’s made from rolled steel that is coated with tin. The coating is chemically bonded to lock them together. Actual tin roofing has not been used for a long time.
What most people are thinking of when they mention a tin roof is a corrugated metal roof. This is actually not a metal type but a form of metal roofing panels. It is usually made of steel or aluminum.
Pros: The tin coating prevents rust from forming. Corrugated panels are usually the least expensive form of metal roofing.
Cons: Corrugated panels’ main drawback is that the fasteners are exposed. This leaves space for moisture to seep in, especially if the metal’s expansion and contraction with temperature changes over the years loosens any fasteners. While special washers are usually installed to prevent this, it can be a problem down the line.
Factors That Will Affect How Long Do Metal Roofs Last
Installation – Proper installation has the biggest effect on a metal roof. Installation by someone who is not experienced with it can cause all sorts of problems, from noise problems to leaky fasteners, to problems because of metal’s natural expansion and contraction, to even cracking of the metal.
Metal roofing is usually installed over a framework that dampens sound and allows for insulation underneath. It can be complicated for someone who has never done it. This is why it’s important to hire an experienced installer.
Weather – Metal roofs can withstand more damage from weather than asphalt shingles or some other roofing types, but it does have an effect. If you live in an area with heavy snow, the stress will cause some wear and tear over the years. Salty and/or humid conditions can cause corrosion problems with some metal roofing types.
Maintenance – While metal roofs don’t need much maintenance, they do need some. They need to be inspected once or twice a year. Tree or other debris should be kept cleared off. Any scratches that go through the paint coating to the metal should be touched up. Keep any gutters and drains clear. Check out my article Which of the Metal Roof Colors Lasts Longest? for the longest lasting metal roof colors.
Why Do Metal Roofs Last Longer?
Metal roofs stand up to weather and other problems that can damage other roofing choices more easily. For instance, large hail may dent your metal roof, but it will crack and break asphalt shingles. With correctly installed panels, especially on a standing seam roof that covers all its fasteners, there is far less chance of water seeping in or under anywhere.
Metal doesn’t deteriorate with age or sun exposure as asphalt shingles do. In fact, many metal roofs feature a reflective coating that not only protects the metal itself but keeps your home cooler in summer. Asphalt shingles eventually become dry and brittle with age and heat and can crack or break more easily.
More expensive options, such as slate tiles, easily break with something falling on them. Wood shakes can also have this problem, and of course, can catch fire in the event of large sparks falling on them from a neighbor’s burning brush pile or fireworks. Check out my article What’s the Best Metal Roofing for a Shed? for more information on types of metal roofing.
How Much Will a Metal Roof Cost?
Prices will vary due to market fluctuations, availability of a particular metal and so on. However, there are some ballpark figures that will give you an idea.
Corrugated metal panels, usually made of steel, can cost between $1.00 and $2.50 per panel. Add in installation, and you end up with a cost of $5.50 to $11.50 per panel.
One hundred square feet of Galvalume, which is steel coated with aluminum, runs between $75 and $250. Installation will run about an additional $5.50 per square foot. Galvanized steel is priced at $3.35 to $4.25 per square foot. Installation added in comes out to around $10 per square foot.
Aluminum costs about $3.50 to $6.50 per square foot in materials alone. Copper and zinc are on the high end, both running about $13 to $25 per square foot.
Another consideration is the type of roofing construction you choose. Corrugated panels are wavy in appearance, with the “waves” on the sides of the panels overlapping. However, the fasteners will be exposed to the elements, as has been mentioned.
Standing seam panels are actually crimped together with a special tool, and the fasteners are all covered. Both the panels and installation may cost more, but you won’t have any worries about potential leaks in the future.
Can You Install a Metal Roof Yourself?
Long gone are the days when you could climb up on your roof, plunk down some “tin” sheets and get happy with your hammer and nails. Metal roofing and its installation are far more sophisticated these days. It usually has a framework installed underneath to provide extra sound dampening and provide an airspace that acts as insulation. Sometimes additional insulation is also installed.
Installing the metal roofing itself is a bit complicated. The natural expansion and contraction of the different types of metal with temperature changes must be allowed sufficient space. Standing seam roofing especially needs special tools and know-how to be installed correctly. Unless you have some experience installing metal roofing, it’s best left to professionals.
Unless you’re roofing a small shed, you’ll need some help as well, and the help must have some experience as well unless they’re just there to hand you materials. If you want your metal roof to last as long as it should, and be as problem-free as it should, it’s best left to professionals who know how to install it.
Metal Roof Disadvantages and Common Problems
Leaking – This can be caused by a number of factors, including fasteners that allow water in, an improperly sealed seam, failed flashing around pipes, valleys and chimneys, and failed sealants. Installation not consistent with the panel manufacturer’s requirements can also lead to leaking problems.
Corrosion – Most metal roofing is coated with special paint designed to withstand and prevent corrosion, but it also must be properly coated on the underside. If moisture gets trapped between the metal and insulation underneath, it could cause corrosion. Installing metal roofing right over a shingle roof without the wooden framework underneath could result in the shingles scratching the coating.
Rusting at the panel edges can also occur if the edges are not properly crimped or protected with a coating. Salt in the air, especially, will have a negative effect on some metals without proper protection.
Oil canning – This is waviness in the flat areas of the roof caused by buckling. This is why care must be taken to allow for metal expansion when the roof is installed. Thicker-grade metals can help prevent this problem as well.
Scratching and scuffing – Scratches and scuffing can be caused by inadequate handling at the factory. It can also be caused by less than carefully walking on it during installation or inspection or dropping tools on it. All panels should be inspected before installation, and any with scratches that go through to the metal should be replaced.
Dissimilar metals – Some metals can interact with others in ways you don’t want. This is why professional installers take care to use the proper types of fasteners to prevent this from happening. Gutters, pipes and flashing materials or trim should also be compatible with the metal roof.
Fading and chalking – This is when the paint coating fades. Most manufacturer’s warranty their coatings for a specific period of time. However, your metal roof will need to be repainted at some point. Adding a roof vent can help with moisture issues and keep your roofing in good condition, read my article Should I Install a Roof Vent for Shed Ventilation? for more information.
What Maintenance Does a Metal Roof Require?
How long metal roofs last does depend somewhat on the maintenance it gets. While metal roofs don’t need much maintenance, but it does need some. It should be inspected once or twice a year for damage. Look carefully for coating or paint scratches that go down to the metal. If you have a lot of scratched areas, you may need to repaint the roof.
These should be touched up to prevent rust, depending on the type of metal you have. The roof should also be inspected after a heavy storm. Debris should be removed, and any badly damaged panels should be replaced. It’s also important to keep any gutters and drains clear to keep standing water away.
Metal roofs do cost more than traditional asphalt shingles, both in materials and installation costs. However, the long-life expectancy will more than make up for the initial cost. Add to this the potential hike in resale value and the discount some home insurance companies give metal roofing, and these roofs just make sense.
If you’re considering metal, take your time deciding what material and what type of construction is best for you. Investigate various installation companies in your area. Besides estimates, ask questions, such as how long they have been installing the type of roof you want, and what warranties they offer on their work. As with any large project, do your homework and it will pay off in the long run.