Buzz
Asphalt shingles tend to absorb a considerable amount of heat, which then infiltrates the structure beneath them.Key Insights
- In warm climates, metal roofs outperform asphalt shingles in energy efficiency by reflecting heat away, potentially lowering energy costs by approximately 50%.
- Although metal roofs require a higher upfront cost, they are more durable and last longer, needing minimal maintenance and replacement compared to asphalt shingles.
- The advanced reflectivity of metal roofs not only cuts down on heat absorption but also provides significant long-term savings through lower cooling costs and potential tax incentives.
Imagine being dared to walk barefoot across hot asphalt or metal. It’s a tough choice, right? Now picture climbing onto a tar-shingled or a metal roof. The debate between which material keeps your home cooler from the top down is clear, though—one of these materials is definitely better at staying cool.
Asphalt shingles are the most commonly used roofing material in North America. In regions like the Southwestern United States, Florida, as well as in Spain, Mexico, and Greece, terra cotta and white tile roofs are widespread. However, in much of the West, asphalt and fiberglass shingles remain the standard choice. These shingles are thin, flat rectangles layered on the roof with overlapping sections to eliminate gaps. They are attached to a plywood surface covered with roofing felt or tar paper using nails and sticky backing.
Metal roofing today goes beyond the simple corrugated tin roofs that might come to mind. It’s available in a variety of shapes, sizes, and textures that mimic traditional roofing materials, including asphalt, slate, and wood, and is often supplied in large, pre-formed panels. Roofing materials like steel, aluminum, copper, and even stainless steel are options, and installation involves aligning panel seams and securing them by snapping or locking them into place. Some metal roofing also comes in shapes resembling traditional asphalt shingles.
Both metal and asphalt roofing serve the purpose of protecting a building, but they differ greatly in terms of durability, energy efficiency, and cost. Asphalt shingles absorb a significant amount of heat, and this heat doesn’t stay confined to the roof; it radiates into the building, raising indoor temperatures by 20 to 25 degrees. Metal roofs, however, reflect the sun's heat away, reducing energy costs by approximately 50% and keeping surface temperatures about 100 degrees cooler than traditional asphalt roofs. Additionally, asphalt shingles weaken and curl over time, making them less reliable against rain, wind, and other environmental elements, requiring regular maintenance and earlier replacement. Metal roofs are more resilient to these factors and last much longer with minimal maintenance.
Which type of roofing is more energy-efficient in hot climates? Without a doubt, metal roofing is the clear winner. But what makes it so effective?
Hot Tin Roof?
For a long time, chickens and cows have lived under the shelter of corrugated tin roofing. As an affordable and durable material, metal is used for agricultural buildings, factory sheds, and temporary housing. However, simply placing a large sheet of tin or metal over walls isn’t likely to save on energy or provide comfort. Metal is highly conductive, meaning it retains a lot of heat. If it’s dull and angled without considering reflectivity, it can trap heat, making the space underneath unbearably hot, like an oven.
Many scouting groups and science classes explore the concept of reflectivity. When a mirror is held at a certain angle to reflect sunlight onto a flammable surface, such as dry grass, it can ignite the surface if left long enough. This demonstrates how powerful the sun's reflected energy can be. Similarly, using a magnifying glass to focus the sun's rays on dry grass can also start a fire due to the concentrated heat.
Modern, energy-efficient metal roofing acts like a giant reflective surface, sending heat and energy into the atmosphere. Light-colored or white metal surfaces reflect heat most effectively, with a reflectivity of around 67 percent, and even some newer ‘cool colors’ can deflect heat as well [source: Florida Solar Energy Center]. Asphalt tiles, while not as powerful as a magnifying glass, absorb and retain heat long after the sun sets. Darker shingles, with a reflectivity of only 22 percent, tend to release the absorbed heat into the surrounding air, raising the temperature beneath them [source: Florida Solar Energy Center].
While most people wouldn’t want a huge mirrored surface on top of their house, many do want the energy savings and relief from constant air conditioning noise. This is achievable with today’s advanced metal roofing. With designs ranging from whole panels to shingle-like pieces, metal roofs have evolved far beyond the humble backyard chicken coop. Whether made from popular materials like steel and aluminum, or more expensive copper and stainless steel, metal roofs suit a wide variety of residential and commercial architectural styles.
But how much will this cost? Next, we’ll explore the environmental benefits and the financial costs involved.
Precious Metal
Metal roofing is more expensive than traditional shingle roofing, but the initial cost is offset by long-term savings.Metal roofing can cost two to three times more than shingle roofing. It’s cheaper than slate or some high-end wood materials, but still represents a larger initial investment for both materials and installation than traditional shingles [source: Metal Roofing Alliance]. However, over time, the savings accumulate through potential tax credits, insurance discounts, and extended warranties [source: MRCA and Metal Roofing Alliance]. Plus, metal roofs are fireproof, require minimal maintenance, and are more eco-friendly by reducing reliance on air conditioning and cooling systems.
While the benefits of metal roofing are impressive, there are a few factors to keep in mind before you hand the job to just anyone with a hammer. Here are some important considerations to think about first:
- The installation process is crucial: Opting for metal roofing means hiring skilled professionals. Poor installation can lead to a less effective roofing system.
- Consider value and time: The savings won’t be visible right away. Long-term savings and the potential for a lifetime roof are significant, but these benefits are best realized if you plan to stay in your property for many years.
- Eco-conscious choices: Many regions now have energy efficiency standards for new construction, and metal roofing offers a variety of options and ENERGY STAR ratings that meet these building codes.
- Conscience and cost: Some people are willing to invest more for environmental benefits, and metal roofing is an effective way to reduce the harmful impact of dark roofs and excessive energy consumption.
- Minimizing waste: Metal roofing helps reduce landfill waste since it is typically installed over existing roofs, eliminating the need to dispose of old tar-covered shingles.
Replacing or repairing roofs in warm climates is always a tough job for the workers involved, but metal roofing offers some impressive long-term advantages. Explore the resources on the next page to learn more.
