A Very Close Look at Metal Roofing – Types, Pros, Cons and Costs

Reroofing your house is a major investment. The choices you make will affect your family’s comfort and the value of your home as well as your bank balance. When researching roofing materials, take a long-term view. Consider not only the initial costs but also the life span, energy efficiency and environmental impact of your final decision. Metal sheet goods and shingles are very versatile and durable materials that compare favorably to other roofing options over the life cycle of your roof.

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The Types of Metal Roofing

The most common types of metal roofing include galvanized steel, aluminum, copper and stainless steel. In general, metal roofing lasts from 35 years to around 200 (Haddock, 2004). In comparison, you may need to replace other materials such as asphalt shingles and wood shakes in as little as 20 years. Metal is fireproof, recyclable and environmentally friendly (Flamholtz, 1984). The primary drawback of metal roofing is its initial expense.

Metal materials are available in rolled sheets, shingles and tiles. Some products feature several color choices. Manufacturers offer stamped and shaped metal materials that resemble cedar shakes, clay tiles or slate as well as the traditional standing-seam panels.

Galvanized Steel Roofing

Galvanized steel roofing is a corrugated sheet metal product that you see on industrial and agricultural buildings as well as on homes. This material typically has a non-corrosive coating, consisting primarily of zinc, that impedes rust (“Corrugated galvanised iron,” 2014).

The pros of corrugated metal roofing include:

• Rust resistant coating
• Lasts 60 years or more
• Lower cost than other metal roofing

The main cons of this roofing material are:

• Industrial-type appearance
• Will rust where coating wears off
• Prone to salt damage in coastal areas

Aluminum Roofing

Aluminum roofing, unlike steel, withstands the corrosive challenges of salt water, so it is a better choice for coastal properties. Aluminum is a lightweight yet softer metal that is subject to denting, so it may not be appropriate in high-wind locations (Vandervort, 2013).

The pros of aluminum roofing consist of:

• Naturally non-corrosive
• Lightweight
• Requires no painting

The cons of this material include:

• Average life expectancy of 35 years
• Soft metal mars more easily
• Higher cost

Copper Roofing

Copper roofing is impervious to rust and does not require protective coatings like galvanized steel and aluminum do. Although more expensive than most other roofing metals, copper is economical in terms of low maintenance and longevity. Copper roofing is particularly adaptable to architectural elements like domes and curved dormers because it is soft and flexible. Over time, the bright penny-toned surfaces develop a greenish patina (“Roofing systems,” 2014).

Among the advantages of copper roofing are:

• Beauty
• Rustproof
• Low maintenance

The cons include:

• Cost
• Easily dented
• Loses luster over time

Stainless Steel Roofing

Corrosion resistant and durable, stainless steel roofing tops such edifices such as the Chrysler Building in New York City. Because of its strength, stainless steel roofing is thinner than some other metal roofing and thus relatively light in weight, so it doesn’t put excess stress on your roof’s understructure. Austenitic stainless steel roofing contains approximately 18 percent chromium and 8 percent nickel. It forms its own protective coating when the chromium reacts with oxygen in the air (“Roofing: the technical guide,” 2014).

The pros of stainless steel roofing include:

• Durability
• Strength
• Low maintenance

Among the drawbacks are:

• Oxidation turns the shiny surface to a dull gray
• Expensive
• One color

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Climatic Considerations When Choosing Roof Materials

Be sure to consider your regional climate when choosing new roofing materials. If you live in a high temperature zone, reflective metal roofing is a smart decision. It repels the heat of the sun before it can make your house intolerably warm. This saves on air conditioning costs.

Some aluminum and steel roofing with optimal solar reflective properties is Energy Star compliant, cutting down on cooling demand during peak usage periods by 10-15 percent (“Roof products,” 2014). In contrast, standard asphalt composition shingles absorb heat and trap it within the home, adding several degrees to the interior temperature. Composition roofing typically deteriorates faster in hot climates too.

In the winter, snow slides easily off metal roofing, reducing stress on the structure and eliminating buildup that could cause destructive ice dams. While some metal roofs do not have as much insulating power as built-up materials like asphalt shingles, they can perform well in cool conditions with adequate insulation.

Environmental Benefits of Metal Roofing

Most metal roofing contains a minimum of 25 percent recycled material (“Energy efficiency,” 2014). Unlike composite roofing, metal roofing is completely recyclable when removed from your home, so it helps cut down on the volume of solid waste in landfills. Because metal products help deflect the heat of the sun, your indoor living spaces require less cooling, saving on energy. In addition, many metal roof products meet or exceed local energy efficiency building standards.

The Final Factor: The Cost of a New Metal Roof

The cost of the roof is likely to be the decisive factor when you make a final decision. In general, metal roof materials cost between two and three times more than standard composition shingles. However, the life cycle cost, including all roof expenses from installation to demolition, is a more practical way to judge what you will pay.

Roofing installers typically charge per “square,” an area equivalent to 100 square feet. An average cost per square for roofing materials and installation is $350, but this varies according to geographic area. For example, a 50 x 30-foot standing seam metal roof in New England costs about 10 percent more than the national average while the same roof in the South Atlantic region costs about 10 percent less (Roof installation prices, 2013).

Low maintenance, energy savings and longevity may more than balance out initial reroofing costs. In fact, the expected life span of a new roof is more relevant in calculating its life cycle cost than the expense of materials and labor (“Calculating the life cycle cost,” 2012). Additional factors that pare down overall cost include energy savings and any tax credits for qualifying materials.

From a life cycle perspective, metal roofing measures up well compared to other materials. With a life expectancy ranging from decades to centuries, an ability to repel punishing solar rays, very low maintenance and complete recyclability, metal roofing turns out to be a wise choice overall for your home, your budget and your environment.
References:

Calculating the life cycle cost of a roof (2012). Buildings, March 26, 2012. Retrieved from http://www.buildings.com/article-details/articleid/13816/title/calculating-the-life-cycle-cost-of-a-roof.aspx

Corrugated galvanised iron (2014). Wikipedia, April 28, 2014. Retrieved from http://en.wikipedia.org/wiki/Corrugated_galvanised_iron

Energy efficiency (2014). Metal Roofing Alliance, 2014. Retrieved from http://www.metalroofing.com/v2/content/metal-roofing/energy-efficiency.cfm#recycling

Flamholtz, Cathy J. (1984). Metal roofing pros and cons. Mother Earth News, March/April 1984. Retrieved from http://www.motherearthnews.com/green-homes/metal-roofing-pros-and-cons-zmaz84mazgoe.aspx#axzz35gSpmGMo

Haddock, Rob. Metal roofing from a to z (2004). Interface, May 2004. Retrieved from http://www.rci-online.org/interface/2004-05-haddock.pdf

Roof installation prices guide (2013). Roof Calculator, 2013. Retrieved from http://www.roofcalc.org/roof-installation-prices/

Roof products for consumers (2014). EnergyStar, 2014. Retrieved from http://www.energystar.gov/certified-products/detail/roof_products

Roofing: the technical guide to stainless steel roofing. The European
Stainless Steel Development Association, 2014. Retrieved from http://www.euro-inox.org/htm/p_5_EN.html

Roofing systems (2014). Copper Development Association. Retrieved from http://www.copper.org/applications/architecture/arch_dhb/arch-details/roofing/

Vandervort, Don (2013). “Types of metal roofing materials,” Hometips, July 22, 2014. Retrieved from http://www.hometips.com/buying-guides/metal-roofing-materials.html

The Average Lifespan of the Most Commonly Used Roofing Materials

Before replacing a roof, it pays to do plenty of research. Like most people, you probably want a roof that will last for decades. It’s also nice to have one that requires little to no maintenance. Several materials are popularly used on roofs in the United States. Some of them are a lot more durable than others. Exceptionally durable materials tend to be more expensive, but cost is not always a reflection of quality because some materials work better under certain circumstances than others. What works for a home in a hot, dry climate may not work for a home in a cold, wet one.

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Factors that Affect the Longevity of a Roof
The material out of which a roof is made has the biggest impact on its longevity. However, other factors come into play as well. Exposure to the sun plays a strong role, and the slope of the roof has a major effect as well. The type of maintenance that a roof receives affects its longevity too. Even when a roof is made out of virtually maintenance-free materials, occasional work is necessary to ensure that it lasts as long as possible.

Popular Roofing Materials and Their Average Lifespans
You shouldn’t base your decision solely on the lifespan of a given roofing material, but this information can help you make the most informed selection possible.

  • Asphalt Shingles – Without a doubt, asphalt shingles are the most popular roofing materials in the United States. On average, this roofing material lasts anywhere from 15 to 30 years. The reason for the wide range involves climate. In colder climates, asphalt shingles may last 25 years or longer; in warmer, more humid climate, they may only last 12 to 14 years. These shingles have petroleum bases that dry out over time, so they definitely don’t last forever.
  • Composite – Composite shingles, or composition shingles, are popular for a variety of reasons. Some of them are primarily made out of asphalt, but there are fiberglass-based options as well. Many composite shingles also include recycled materials, so they can be eco-friendly options. While they require very little maintenance and are quite adaptable, they don’t have great lifespans. On average, you can expect a roof made out of composite shingles to last about 20 years. If you live in an area that regularly experiences high winds, composite shingles are not a good option.
  • Metal – Metal roofs have experienced a surge in popularity in recent years. In addition to having extremely long lifespans, these roofs dramatically enhance the energy efficiency of homes. Standing-seam metal roofs, which are the most popular, can last 75 to 100 years. Metal roofs are resistant to fire, insects and rot. Very little maintenance is needed, but it should still be performed. Metal roofs should be inspected periodically, and they should be scraped and repainted with rust-resistant paint when needed. As long as this basic maintenance is performed, a roof like this should serve you well for a long time to come.
  • Tile – Most people are drawn to tile roofs for their beauty. Tile is most commonly used on homes that have Spanish or Italian architecture. In addition to looking great, tile roofs can last a really long time. Some have lifespans of up to 100 years. Unfortunately, tiles are often installed on mortar bed systems, which makes them susceptible to slippage. In that case, this type of roof may only last about 10 years. Therefore, exceptional installation is critical. Because tiles are often made out of terra cotta and other dense materials, they tend to be heavy. Extra support is often needed. Tiles are also fragile, which presents a problem when performing maintenance on a roof.
  • Slate – For a natural, stunning look, it’s tough to beat slate. Very fine slivers of stone are used to create these roofs, which have lifespans of 45 to 75 years when they are properly maintained. Like tile, slate can be very fragile, and it can require extra support due to its weight. The thickness and density of slate tiles affect their longevity. Slate roofs generally require very little maintenance. However, the main thing that affects their longevity is failure of fasteners and nails. These components should be inspected regularly and replaced promptly at the first sign of weakness.
  • Wood – Estimating the lifespan of a wood roof isn’t easy because so many factors affect its durability. The slope of the roof, the amount of sun exposure it receives and the quality of the maintenance that’s performed all have an impact. Furthermore, the width, thickness and cut of the wood affect its longevity as well. When properly treated, installed and maintained, the average wood roof should last 15 to 30 years. Out of all of the available options, cedar is the best choice.
  • Fiberglass – Homeowners love the versatility and style of fiberglass roofs. This option is sold in panels and sheets, which makes it easy to achieve the perfect look and protection. The fiberglass that’s used is glazed to make it exceptionally waterproof. Fiberglass is also naturally shatterproof, so it’s a strong, durable choice. The best fiberglass roofs are designed to be resistant to rot, mildew and rust. At the high end of the scale, a fiberglass roof should last around 30 years. As with other roofing materials, maintenance and design have major impacts on the lifespan of this type of roof.
  • Concrete – People are often surprised to learn that concrete can be used as a roofing material. A concrete roof doesn’t involve heavy slabs of material. Today’s best options use fiber-reinforced cement to achieve optimal style and durability. When mixed with cellulose, concrete can be crafted to look like wood shakes. Concrete roofs can also be used to replicate tiles and other popular roofing materials. Depending on the design of the roof and its underlying materials, concrete shingles or panels can last up to 50 years. This type of roofing material is virtually maintenance-free, and it’s resistant to rot, insects and fire.
  • Rubber – Although it’s infrequently used, rubber is a viable roofing material in many situations. Most people turn to it for its eco-friendliness, but it has other benefits too. A rubber roof offers exceptional energy efficiency. Shingled rubber roofs are available, but whole-roof designs, which are custom-created at the factory, are much better options. These rubber roofs are seamless, so they are exceptionally leak-proof and can last up to 40 years. Rubber roofs are also flexible and lightweight, and they are available in a variety of colors and designs.

Before considering any roofing materials in earnest, give some thought to the climate where you house is located. Is it usually wet or dry? Is it usually sunny or cloudy? Would you describe it as a warm climate or a cold one? These factors will all help you zero in on the ideal roofing material. From there, weigh the pros and cons of the top options, and remember that cost doesn’t necessarily reflect quality. Regardless of the material that’s used, first-rate installation is vital. To ensure that your roof lasts as long as possible, make sure that it is inspected and serviced regularly.

The Most Common Types of Roofing Materials in the Pacific Northwest and Why

Since a roof serves to keep out the elements and protect the house below, the choice of roofing materials varies heavily from region to region across North America. In the Pacific Northwest, homeowners need to deal with heavy rainfall and very high humidity levels, so every roof needs to be water-resistant. Choosing the right materials is extremely important because water damage can cost tens or even hundreds of thousands of dollars to repair. Conversely, a roof that drains well and resists water damage can stay in place for a long time before needing replacement.

Probably the most common roofing material used in the Pacific Northwest today is asphalt. Custom-designed asphalt shingles can closely imitate the appearance of wood, ceramic, slate or metal shingles at a significantly lower cost, and the material is naturally durable and resistant to water and heat. Still, because asphalt is a porous material, these shingles are somewhat susceptible to mold or algae growth and require a degree of maintenance. Furthermore, many home buyers prefer the natural appearance of wooden shingles, so opting for asphalt can reduce the sale value of the home. Generally speaking, an asphalt roof will last about 20 to 30 years.

Thanks to their widespread availability in the region and relatively low cost, cedar and redwood are two of the most popular roofing materials among Northwestern homeowners. Both of these woods are generally considered to be fairly attractive and, if properly maintained, can last up to 50 years before needing replacement. Furthermore, redwood or cedar shingles tend to add to the value of the house. However, a roof made from cedar or redwood is inherently vulnerable to rot, algae or moss. Water-resistant treatment can reduce these risks, but homeowners who opt for one of these materials should still expect to pay for frequent maintenance. Thus, the benefits of a classic, natural-looking roof must be weighed against the cost and effort required to keep the roof maintained.

Metal shingles, most commonly steel, offer excellent water resistance and typically require less maintenance than other roofing materials, making them ideal for hands-off Northwestern homeowners. Most metal roofing products come in a “standing seam” style that consists of a series of interlocking panels. Like asphalt shingles, metal shingles can be custom-designed to mimic other materials such as cedar, redwood or slate. They tend to be more expensive than asphalt, but can last up to 50 years if properly installed and maintained.

Many recently constructed homes in the Pacific Northwest use roofing tiles made from clay or concrete. Vitrified clay tiles, which are almost glass-like thanks to a special hardening process, are available in a variety of colors and styles. Because they are almost impervious to water damage, clay tiles can last 100 years or more before needing replacement, but they are heavy and quite expensive. Concrete tiles are cheaper than clay, but retain the same weight disadvantage and do not last quite as long. Despite their disadvantages, tile products have become increasingly popular in the rainy Northwest over the last quarter-century.

Clay Roofing Tiles

Regardless of material, every home in the Pacific Northwest needs a roof designed to deal with the heavy rain. As a rule, flat sections of roofing are not desirable because they allow water to pool and cause mold, mildew or other damage. Most homes use V-shaped gable roofing or four-sided hipped roofing to allow water to run off easily.

Whether they opt for asphalt, wood, metal, tile or another roofing material, homeowners in the Pacific Northwest need to be conscious of the weather in their region and the hazard posed by the heavy rainfall. Every roof needs to be designed with water resistance in mind and frequently inspected and cleaned to prevent water damage. Each material comes with advantages and disadvantages in terms of weight, cost, durability and maintenance. By taking all of these factors into account, Northwestern homeowners can select the right roofing materials to meet their homes’ individual needs.