Asphalt shingles are one of the most popular residential roofing styles in the United States, with more than 12.5 billion square feet of products manufactured annually—enough to cover five million homes every year. In addition to offering a broad array of colors, shapes and textures, asphalt shingle roofs can match almost every type of architectural design and are low maintenance, easy to apply, and resistant to fire and wind.
Even though asphalt shingle roofs have numerous benefits, it’s still important to take your personal preferences and living situation into account before making a purchasing decision. Here’s some basic information about the most common styles of asphalt shingles:
Strip shingles. These asphalt shingles are approximately three times as long as they are wide. Manufactured in both standard and metric dimensions, strip shingles are distinguished by the number of cutouts or tabs they have (the most common type is “three tab”). Different textural and lighting/shadowing effects can be achieved with strip shingles depending on the number, shape and alignment of the cutouts.
Laminated shingles. These special shingles contain more than one layer of tabs to create extra thickness. They’re also referred to as three-dimensional or architectural shingles because they create visual depth on a roof and impart a custom look. Laminated shingles are popular among builders, roofing contractors and homeowners.
Interlocking shingles. As the name suggests, interlocking asphalt shingles are individual shingles that mechanically fasten to each other and are used to provide greater wind resistance. They come in various shapes and sizes, providing a wide range of design possibilities.
Large format shingles. Generally rectangular or hexagonal in shape, large format shingles don’t utilize cutouts or tabs.
Caring for asphalt shingle roofs
When the weather gets humid, asphalt shingle roofs can develop dark streaks that are often attributed to an accumulation of dirt, defective shingles, mold and mildew. The most common culprit is actually blue-green algae called Gloeocapsa Magma, which is spread by airborne spores. While algae growth does little harm to the roofing itself, the stains can affect the overall appearance or resale value of your home. Luckily, removing these algae is a relatively simple process.
Mix the following ingredients and pour them into a pump-type garden sprayer:
• 1 quart of bleach (6% sodium hypochlorite)
• 1/4 cup of trisodium phosphate (TSP) or another heavy duty cleaner
• 1 gallon of water
After wetting down the roof with the solution, allow it to remain for about 15 minutes before rinsing it off with a hose.
To keep algae from returning once your roof is clean, install a strip of copper or zinc coated sheet metal along each side of the roof just below the ridge. While copper is more toxic to algae, galvanized sheet metal is much less expensive. Both copper and galvanized metal are available to purchase online or from local metal suppliers in rolls of various width and thickness. Narrow strips of sheet metal can be attached directly to your roof using roofing nails or screws with rubber washers. For wider pieces of sheet metal, loosen the self-sealing tabs on the top row of shingles with a putty knife, slip part of the sheet metal under them and use roofing nails to nail it in place.
