Asphalt Shingles

• Asphalt composition shingles are the most commonly used roofing material in the United States, according to U.S. Inspect. They are usually sold as rectangular strip shingles, with the most common size being 12 inches wide by 36 inches in length, according to the National Roofing Contractors Association. Their thickness is commonly one-eighth inch, with asphalt shingles containing glass fiber being slightly thinner.
  
  

Wood Shingles

• In the United States, wood shingles are available in lengths of 16, 18 and 24 inches, the length being the vertical measurement. Widths are generally not standardized. The typical thickness of wood shingles is three-eighths to one-half inch, according to Carson Dunlop in "Principles of Home Inspection: Roofing."
  
  

Metal Shingles

• Metal shingles come in a wide variety of shapes and sizes, and are often created to look like wood shingles or clay tile, which do not last as long as metal. Common sizes include 12 by 24 inches; 9 by 12 inches; 10 by 60 inches; 12 by 120 inches; and 45 by 60 inches, according to Dunlop, with thicknesses ranging from .016 to .021 inches.
  
  

Choosing Shingles

• Factors to consider when buying shingles include price, durability and visual appeal. Besides blending in with your house, shingle color reacts with weather conditions. Light colors reflect heat; darker colors absorb heat and work well in colder climates.
  
  If you want to focus on green building, one factor to keep in mind is that asphalt and some wood shingles affect the environment more because they require more frequent replacement than other types of roofing, and they therefore contribute to landfills more, according to the Minnesota Sustainable Housing Initiative website.