Metal roofing is long-lasting, good at keeping a home cool, holds up well in most weather conditions, and is environmentally friendly; its downside is that it costs more upfront to buy materials.
Asphalt shingles offer better soundproofing and are initially more affordable, but they do not last as long as metal roofing, especially in extreme weather conditions, and therefore may cost more in repairs over time.
Asphalt shingles are called "bitumen shingles" in some regions of the world.
|Asphalt shingle||Metal roof|
|Cost||Low upfront cost, high long-term cost as repairs and replacements will be needed. Materials are inexpensive, labor required for installation less so.||High upfront cost, low long-term cost. Some federal "energy saver" rebates exist.|
|Durability||Somewhat durable, with asphalt-fiberglass shingles more durable than organic-asphalt shingles. Usually lasts 15-30 years and professionally installed asphalt shingles are backed by 20- to 25-year warranties.||Very durable. Often backed by 50-year to lifetime warranties.|
|Heating/Cooling||Good at keeping in heat during in winter, but one of the worst types of roofing for keeping cool during summer.||Adequate at keeping a home warm during winter, and one of the best types of roofing to keep a home cool during summer.|
|Fire Resistance||Asphalt-fiberglass shingles are very fire resistant. Organic-asphalt shingles are not fire resistant.||Some metals more fire resistant than others. Copper and steel are good, aluminium less so.|
|Soundproofing||Good.||Good with proper insulation.|
Determining whether metal roofing or asphalt shingles are appropriate for a home, and which will cost less overall, often comes down to region, as the two types of roofing behave very differently in different climates. Asphalt shingles will work best in temperate climates, while metal roofing can work well in hot or cold, wet or dry, extremes, but will cost more upfront.
Though it may seem counterintuitive, metal roofs work well in hot climates. In fact, they keep a home much cooler than asphalt shingles do, potentially decreasing peak cooling demand by 10-15%. Metal reflects sunlight, keeping it cooler inside, while asphalt shingles, particularly black ones, absorb the heat of the sun, making a home that much warmer. New, white- or light-colored metal roofing with proper ventilation is better than old metal roofing, and special sealants can further cool down the material.
Because asphalt shingles absorb heat, they may be better at keeping a home warm in wintertime, but with proper insulation, a metal roof should do just as well. Moreover, according to the EPA, the summertime savings of a metal roof—deemed a "cool roof"—are so significant in some regions that annual energy spending will still be lower overall with a metal roof, even if a little more heating is required.
One major downside to asphalt shingles in wintertime is that they may not survive layers of heavy, wet snow. The cold temperatures can cause the asphalt to crack, which may then result in a leaky roof. In contrast, snow slides off a sloped metal roof, and the cold temperatures cause no harm to the metal.
Metal roofing is much more durable than asphalt shingles. It's not uncommon to find metal roofing backed by 50-year or even lifetime warranties, while asphalt shingles tend only to last 15 to 30 years and come with 20- to 25-year warranties.
Metal roofs survive the elements well, remaining intact when facing high winds, hail, and lightning; they are more likely to withstand extreme conditions, like hurricanes. Asphalt shingles can withstand some extreme weather if installed properly, but it's common for homeowners to have to replace shingles or whole parts of a roof after bad storms, high winds, or heavy snow. In general, asphalt shingles are prone to a number of climate-related problems, such as algae growth in prolonged humidity.
When it comes to fire resistance, materials matter. A copper or steel metal roof will survive well, for instance, but an aluminum one will eventually melt. Likewise, shingles made from an asphalt fiberglass composition are fire resistant, while those composed with organic wood are not.
Asphalt shingles are quieter than metal roofing, especially in heavy rain, but some may think metal roofing is much louder than it actually is. A metal roof on a home is different from the bare tin roofing of a barn or event center and is much quieter. Regardless, there are numerous ways to reduce noise with either type of roof. Using insulation, particularly having an insulated attic between living areas and the roof, greatly reduces noise.
For metal roofing, some local building codes allow homeowners to install the metal roof over an asphalt shingles roof; this can be ideal for those concerned about noise who are already planning to re-roof their home.
Metal roofing comes in several overall styles, including vertical and standing seam panels, tiles, slates/shakes, and shingles. They can come pre-painted or be painted after installation; any color is fine, but lighter colors are better at reflecting the sun's heat. One possible downside to metal roofing is that, even when tiles or shingles are mimicked, there is no getting around the fact that the material has a metallic sheen to it.
Today, asphalt shingles are cut and colored in a multitude of ways to mimic other materials and styles. However, like metal roofing, asphalt shingles retain at least some of the look of their material. The most common colors are greys, browns, reds, greens, and blues.
One reason so few American homes use metal roofing is because its initial cost is usually two to three times higher than that of asphalt shingles. In Massachusetts, the re-roofing of a 2,000 sq. ft. home with asphalt shingles costs around $8,000 and would last 15-20 years. Metal roofing the same home with aluminum would cost about $20,000. Metal roofing is likely to make up for its high price tag over time, though, especially in certain climates or in places where electricity is expensive. In the U.S., federal rebates exist for qualified metal roofing materials.
Meanwhile, the biggest cost of asphalt shingles is less likely to be connected to the material than it is to the labor—the expense of installation—which varies from place to place. Unless you are installing the shingles yourself, you should consider purchasing a long-term warranty from the shingle manufacturer. Self-installation is not recommended, as most warranties do not apply to DIY jobs.
Outside of material and labor costs, other factors play into the overall pricing of a roof, including how steep it is. To best determine the cost and/or savings of different roof types, use Oak Ridge National Laboratory's roof savings calculator.
The most common type of metal used in metal roofing is steel, but aluminium, copper, tin, zinc, and other metals are also in use. Some materials are better for certain environments than others; aluminium, for example, is better suited to humid climates than steel is. Regardless of the metal chosen, however, all metal roofing is very environmentally friendly. Most metal roofing comes at least partially from recycled metal, and at the end of its life, the metal can be fully recycled again.
Asphalt shingles come in two forms: shingling that is mixed with fiberglass and shingling that is organic, a paper shingle with an asphalt coating. The asphalt shingles that are mixed with fiberglass are more popular than the organic ones because of they are less expensive, are more resistant to fire, and are more flexible. Organic asphalt shingles are more durable because they use more asphalt in their composition than the asphalt shingles that are mixed with fiberglass, but this has the downside of being less environmentally friendly, and the paper of organic asphalt shingles makes them more hazardous in a fire.
Though asphalt shingles are the most popular type of residential roofing in America, metal roofing is growing in popularity. In 2013, a McGraw-Hill Construction and Analytics survey revealed that 12% of re-roofing projects were using metal; this was up from 4% in the late 1990s.
- Wikipedia: Asphalt shingle
- Wikipedia: Metal roof
- Wikipedia: Roof shingle
- Asphalt Shingles 101 - BobVila.com
- Asphalt Roofing Gallery - Asphalt Roofing Manufacturers Association
- Cool Metal Roofing (PDF) - The Metal Initiative
- Cool Roofs - EPA.gov
- Guidelines for Selecting Cool Roofs - U.S. Department of Energy
- How Metal Roofs Keep Arizona Homes Cool - Phoenix Roofing Team
- How to Diagnose and and Repair Roof Noise Problems in Buildings - Inspectapedia
- Metal Roofing Materials - RooferCalculator.com
- Reducing Urban Heat Islands (PDF) - EPA.gov
- Roof Fire Rating Classification and California Code Requirements - Center for Fire Research and Outreach
- Staying Cool With a Metal Roof - GreenBuildingAdvisor.com
- Tax Incentives for Metal Roofing - Metal Roofing Alliance