How long does a steel roof last

Whether roofing a new home or outbuilding or reroofing it, choosing the best material can be a challenge. It can be a matter of aesthetics, budget, or the logical process of how long will it last. So, if you’re wondering how long do metal roofs last, we’re here to help!

A metal roof can last more than 100-years, but the typical life span is between 40 and 75 years. The type and thickness of the metal, whether it’s sheet, shingle, or roll roofing, and the style of roof affect longevity, as do environmental factors and maintenance. Compared to a 25-year shingle that only lasted 12, that’s impressive.

In this guide, we’ll look at how long metal roofs and metal roofing screws last on average. We’ll discuss different factors that affect the roofing’s life expectancy, how long the color will last, and rust concerns. We’ll compare tin roofing and shingle life span, plus explain how often metal roofing should be replaced, how to make it last longer, and identify the longest-lasting roofing material.

Quick Navigation

• How Long Do Metal Roofs Last on Average?
• How Long Does A Metal Roof Last In Florida?
• How Long Do Metal Roof Screws Last?
• What Affects Metal Roof Life Expectancy?
• How Long Does The Color Last On A Metal Roof?
• Tin Roof vs Shingles Lifespan
• Do Metal Roofs Rust?
• How Often Should Steel Roof Be Replaced?
• How Can I Make My Metal Roof Last Longer?
• What Is The Longest Lasting Roof Material?
• Conclusion

How Long Do Metal Roofs Last on Average?

Metal roofing, commonly referred to as tin roofing, comes in sheets, panels, shingles, and rolls. It may have hidden or exposed fasteners, and it can be smooth, ribbed, or stamped. The roofing metal is available in different gauges or thicknesses, and even different compositions or types of metal.

The life span of metal roofs, like everything, depends on different factors. Longevity depends on the type of metal, gauge, kind of roofing material, roof-style, and maintenance. While the average is between 40 and 75 years, some will begin to fail sooner, and others will keep working long after their 100-year milestone. Some metal roofing is warrantied for 25-years, others for 50 years, and there are some with lifetime warranties.

Galvanized steel roofing will last 40 to 75 years or longer. Copper roofing has been used on large or important buildings for almost a millennium. Zinc roofing will outlast galvanized steel. Tin roofing was available before steel and is lighter, and will last 50 to 100 years or more.

Aluminum roofing is lighter than steel and typically will last 30 to 60 years. Galvaluminum, or galvalume metal roofing combines steel, aluminum, and zinc, and will last 180 or more years.

How Long Does A Metal Roof Last In Florida?

Some styles or profiles of metal roofing may last 20 to 50 years in Florida, and others may last 70 or more years. Much depends on how it is fastened, roof-style, thickness and type of metal, and location. Airborne ocean salt can cause scratches and screw holes to rust, and even weaken the fasteners too. Adherence to strict building codes in Florida helps ensure the roofing stays put during hurricanes, but if the wood structure fails, the metal won’t roofing won’t last.

How Long Do Metal Roof Screws Last?

The type of metal roofing screw and the composition of the washer material, along with climate affect the life span of screws and other fasteners. Exposed versus hidden fasteners is another factor to consider too. Fasteners should be checked once or twice a year or after major wind storms. They should last between 10 and 20 years with regular checking and maintenance, or longer based on different factors.

Galvanized steel, ceramic coated, and stainless-steel screws are typical fasteners and come with rubber, plastic, nylon, and even lead washers. Some screws and washers are made from military-grade material and last longer. The washer protects the screw hole and keeps moisture out. Temperature, UV rays, airborne chemicals, ice, snow, and winds can damage the washer.

The wind can cause vibrations that damage the seal or wear off protective coatings on the screw making it susceptible to corrosion. Temperature can degrade the washer and cause it to fail, heat and cold also cause metal roofing to expand and contract, which can damage both the washer and the screw.

UV rays and chemicals can cause some washers to dry out or become brittle, causing them to fail. Ice and snow sliding off the roof can also lift or rip screws out, so checking in the spring is advisable.

What Affects Metal Roof Life Expectancy?

The life expectancy of metal roofing is affected by weather conditions or climate, sun exposure, roof color, pitch, debris and moss, installation practices, and maintenance. The location determines the climate, which in turn affects the typical weather experienced. Roofs in areas with little to no snow or ice will last longer than those in heavy snowfall areas, while areas with hot sunny climates may experience hurricanes or tornado-like winds that can damage or remove roofing.

The sun’s heat and UV rays can damage finishes and fasteners, which can lead to roof failure over time. Dark-colored roofs absorb and transfer more heat into the house than lighter-colored roofs. The greater heat can cause expansion which can damage fasteners and washers.

A steep slope or pitch can shed moisture much more quickly than a low slope, but in snow areas, that extra speed can also rip out fasteners. Low sloped roofs may also be susceptible to ponding, which can damage the metal too.

Debris and dirt can damage roofing material too. Branches can scratch protective coatings, dust or dirt can help moss or lichen to grow, which accelerates roof deterioration. Poorly installed roofing won’t last as long as that which is properly installed. It’s better to pay for quality than to cut corners.

A well-maintained roof will outlast most people. Keeping debris off the roof, checking, tightening, or replacing fasteners, clearing downspouts and gutters, and recaulking around chimneys and vents is a small price to pay when you consider the roof protects the whole house.

How Long Does The Color Last On A Metal Roof?

Metal roofing lasts for decades and is available in a variety of colors, however, some colors will fade or chalk more than others. Colors are warrantied for 10 to 40 years or more against fading and chalking depending on the type of color coating.

The type of pigment and resin used in the paint affects fading. Organic or natural pigments are brighter or richer looking but are more susceptible to fading. Inorganic or ceramic paints are made of mineral compounds like metal oxides and engineered to last longer, which they do.

The resin used in the paint also affects the color as it is what bonds the pigment to the metal. Polyvinylidene fluoride (PVDF) is currently the best protective coating and usually carries a 40-year warranty against fading and chalking. Silicone-modified polyester (SMP) resins are almost as good and carry warranties of 35-years.

Plastisols is a plasticized vinyl resin and is commonly used in corrosive, very hot, or very cold climates; it can change pigment colors, though. Polyester, a synthetic polymer is the least expensive option and usually is warrantied for 10 years.

Fading is commonly caused by pollution, precipitation, temperature extremes, and UV rays which can break down protective coatings and typically lightens the color, although some colors may darken. Most panels don’t fade in a uniform manner as exposure to some elements isn’t the same, much like clothing worn and washed repeatedly.

Chalking is a white powdery residue often seen on coated or painted metal roofing and siding. UV rays and sunlight will break down the resin base, causing it to degrade and lose its adhesive properties.

The separating particles degrade and turn to a whitish powder, which can change the pigment color. Wipe a dark-colored cloth on a section of metal roofing with 3 to 5 pounds of pressure and see if it picks up the chalky material. The amount of chalk identifies how much the paint has degraded.

Tin Roof vs Shingles Lifespan

The length of time any roofing lasts depends on location which can affect UV exposure, precipitation, temperature extremes, airborne salts and chemicals, wind forces, organic debris, and pollution. The greater the exposure to any or all of these, the faster the roofing will degrade. However, asphalt shingles will deteriorate more quickly than metal roofing in the same environment.

Where I live, the common adage is: ‘buy 25-year shingles and hope for 12’, whereas most steel roofing will last 40 to 75 years or more. Plus, SMP or PVDF coated steel will resist fading or chalking for 35 and 40 years respectively, so steel roofing will easily last 3-times – or more – longer than asphalt shingles.

Asphalt shingles are less expensive and ‘easier’ to install than steel roofing. The overlapping multi-layer aspect and the fact that shingles don’t expand or contract with temperature is a great preventative against leakage. Unfortunately, pollution, organic debris, wind, and other climatic issues can cause the shingle to curl, warp, and crack, exposing the roof structure to moisture.

Steel roofing, if properly install and maintained, also is an effective barrier against leakage. However, wind, snow, and ice, along with temperature extremes can damage seals, screws, and washers, resulting in leaks – hence the need for regular and proper maintenance. While the asphalt shingle has to be replaced, the steel just needs a new screw or sealant to make it as good as new.

The quick answer is, Y-E-S. The amount of iron in the metal and the type of protective coating, along with environmental issues and maintenance affect the speed at which the metal can rust. Most metal roofing in North America is galvanized steel, so steel coated with zinc for protection. Unfortunately, holes drilled for or by fasteners and any scratches can damage the protective zinc and paint coatings, allowing the metal to rust.

Non-ferrous metal roofing, such as aluminum and copper, don’t rust, even if scratched. They are softer, lighter metals and easier to damage, plus they oxidize or change color. Aluminum shingles, however, are available with a protective color coating which typically carries a lifetime, transferable warranty. Transferable as it will outlast the purchaser and is passed on to the new owners.

How Often Should Steel Roof Be Replaced?

A steel roof should last 40 to 75 years or longer depending on pollution, environmental issues, and maintenance. Copper, zinc, and Galvaluminum will last 100 years or more. So, aside from a natural disaster or fire, you shouldn’t need to replace a properly installed and maintained steel roof within the lifetime of the original owner. Remember, maintenance includes tightening or replacing damaged screws, washers, and seals.

If, however, you purchase or own a house and the roof is showing rust marks or streaks stemming from fasteners it might be time to replace the roofing. Over time, screws may rust through and the screw holes begin to rust out and the deterioration spread, as can edges and scratches through the protective coatings rust. A good inspection by a professional is advisable. They may suggest minor repairs or the replacement of the metal roofing depending on the extent of the damage.

How Can I Make My Metal Roof Last Longer?

A well-maintained metal roof will last longer and protect your home, belongings, and investment longer than asphalt shingles. Maintenance, however, is the key. Here are some suggestions to help make your metal roof last longer:

• Visually inspect the roof every 6 or 12 months, and after heavy wind storms. Look for raised, loose, or broken screws. Check calking and seals for cracks or deterioration, including flashing and around chimneys and vents. If you can inspect the underside of the roof deck, look for water stains or marks.
• Make sure gutters and downspouts are clean and clear of obstructions in the spring and fall and make repairs sooner rather than later. This prevents moisture back-up and damage to the roof deck.
• Lift and remove branches and other debris to prevent scratches and other damage.
• Wash the roof, if possible, once or twice a year to remove dust, dirt, leaves, and other organic material which can scratch, damage, or deteriorate the protective coating or paint. This will also prevent the growth of molds and mosses, which should also be removed and washed if they appear.
• Trim or remove overhanging branches to protect the metal and paint from scratches and organic damage.
• Remove or prevent ice dams that can cause moisture damage and damage gutters and downspouts. Be careful not to damage or scratch the metal roofing.
• Address rust spots as they appear on roofing and flashing.
• If inspection and repairs are not in your skill box, hire a licensed contractor.

What Is The Longest Lasting Roof Material?

Although different roofing materials will last longer than others, some have a proven history of longevity. Asphalt will last between 5 and 20 years, wood shingles or shakes 25 to 35 years, metal roofing 40 to 75 years, and clay tiles or cement 50 to 100 years. Within each of those categories there will be some that don’t last as long, and others that last longer. However, the queen bee of all roofing is slate.

Properly installed and maintained slate roofing will last hundreds of years. There are some buildings in different parts of the world where the original slate tiles were installed more than a millennium ago and are still going strong. Slate tiles are resistant to mold, mildew, and warping, and are extremely durable. Slate is also heavy and expensive to install, so isn’t commonly used in most residential construction.

Conclusion

A metal roof will last between 40 and 75 years if properly installed and maintained. Different metals like zinc or copper will last longer than ferrous-based ones, easily pushing past the century mark in longevity. Hopefully, you have a better understanding of how long metal roofing will last, and the factors that affect its life span.

Eugene has been a DIY enthusiast for most of his life and loves being creative while inspiring creativity in others. He is passionately interested in home improvement, renovation and woodworking.