The purpose of the roof is to protect the structure’s interior by shedding water.  A roof is a system of design and materials working together as a shield against the external world and the weather.

The slope of the roof is important as roofing materials are designed to work effectively on specific slopes. Determine the slope by taking the 12-inch run (horizontal measure) and measuring the vertical rise 12-inches in from the edge.  The slope is described by the rise over the 12 inch run, such as 6/12.

A  2/12 or 3/12 is considered a low slope roof.  Manufacturers will note the slope minimums for their materials and will not warranty materials used improperly.

Building codes will affect what materials can be used, such as in areas of heavy wind or wildfires.

Installation may be performed by do-it-yourselfers with some of the materials; others will require a professional who is familiar with the proper installation techniques to maintain the manufacturer’s warranty.

Is this a new roof? reroof?  Will the old roof be ripped off or new roof installed over the original roof? All of these factors will have an impact on the material chosen and the cost of the project.

Architectural style of the home should be considered when choosing the roofing material, color, and style. The curb appeal of the structure will be enhanced by the roof; up to 40 percent of a home’s appearance from the street can be the roof.

Know the life expectancy of the material to be used.

Asphalt shingles are the most frequently used roofing material. The mat base may be made or an organic wood, such as paper, or of fiberglass. The mat is saturated with asphalt and topped with mineral granules. Can be used on fairly low slope to steep slope roofs.

Three tab shingles — most commonly used — are manufactured flat with two notches in the panel, creating three tabs. Least expensive and easy to install, they come in an array of colors. Check the manufacturer’s warranty for wind resistance and life span.

Architectural shingles are manufactured with several layers of mat forming a  thicker panel that provides a multi-dimensional look. Since the shingle panel is thicker and heavier, it will have a higher wind resistance and a longer life span.

Synthetic roofing is composed of rubber or a plastic polymer and made to look like asphalt shingles, slate, or wood shakes. Can be used on moderate to steep slope roofs. Good fire and wind resistance.

Metal roofing is constructed of panels or shingles from a variety of metals, such as steel, aluminum, zinc alloy or copper. Painted or unpainted, metal roofs can be used on low to steep sloped roofs. Excellent fire and wind resistance.

Wood shakes and shingles are milled from a variety of wood species such as Cedar, Cypress, Pine and Redwood. The difference between a shake and a shingle is the shape and thickness. Shakes originally were split by hand from a log and appear rough. The shake tapers in thickness and shape. Now, many shakes are machine made, but will be finished to appear rough, but still taper in thickness. Shingles are sawn and even in thickness with a smooth finish. Wood preservatives impregnate the wood for longer life expectancy. Not fire proof. Can be used on moderate to steep slope roofs.

Slate shingles are created from natural slate. While many are gray, multi-colored slate shingles are available. Due to the nature of creating the slate shingles, they provide a thick, multi-dimensional, sturdy look to the roof. The varied color slate shingles last more than 100 years if installed properly; the gray slate does not have the same life expectancy.  Fire and wind resistant, due to the weight, slate shingles will require additional structural support. Install on steep slope roofs.

Clay tiles are fired with a barrel/rolled shape or flat for use on homes with a Spanish or Italian style architecture. Fire resistant, the tiles are heavy and may require additional structural support in the roof framing. For use on moderate to steep slope roofs.

Concrete tiles are manufactured from Portland cement and sand to mimic the look of clay tiles, wood shakes or even natural slate. Fire resistant, concrete tiles are heavy and may require additional structural support in the roof framing. For use on moderate to steep slope roofs.

Corrugated roofing is made from asphalt, PVC and fiberglass refers to the shape of the sheet created.

Corrugated asphalt sheets are similar to asphalt shingles but are easier to install due to the larger size of the panel; can be installed over an existing roof for a less expensive alternative to re-roofing. Moderate to steep slope roofs.

Corrugated PVC and fiberglass are not installed on homes, but on sheds, carports or other outdoor structures that need protection.

Installation prices will increase the costs of the materials. Budget for professional installation on most of the materials.

The Life Expectancy of the material also should be considered when making a decision. Some asphalt shingles have a lifetime warranty of 25 – 30 years, but synthetic, clay and concrete tiles will have a 50 plus year life expectancy. Factor how frequently the building will need a new roof and if the same people will still be occupying the home.

Type of Material -

    •  Asphalt shingles are the least expensive of the residential roofing materials.

    •  Synthetic Roofing is more expensive due to the manufacturing process.

    •  Metal roofing will vary in pricing depending upon the metal used: painted steel is much less expensive than copper. But, copper provides an aesthetic that cannot be captured by other materials and may be worth the investment.

    •  Wood compares to the cost of lower priced metal, but will vary depending upon the wood species.

    •  Clay tiles are expensive and may require an investment in reinforcing the roof structure due to their weight, but provide an individualized aesthetic.

    •  Concrete tiles cost about half the natural clay tiles. Concrete tiles also are heavy and may require an investment in reinforcing the roof framework.

    •  Corrugated asphalt sheets are less expensive than asphalt shingles and are sold by the sheet and not by the square foot coverage.

    •  Corrugated PVC and Fiberglass are a good investment value for their usage.