Selecting Roofing Materials

Slope

The slope (also known as the pitch) of your roof also affects which materials you can choose. Roofing materials for a low-slope roof (less than 2:12 pitch) must meet more stringent requirements than a steep-slope roof.

The slope will also be a factor in how expensive it is to install your roof –generally, the steeper the pitch, the more expensive the labor.

Considerations for Low-Slope Roofs

Keep these issues in mind as you consider different materials.
If you have a low-slope roof, water-resistance and solar-reflectiveness are key, while appearance may be less important, as your roof will not be highly visible from the street.

Considerations for High-Slope Roofs

For roofs with a steep slope, aesthetic considerations become more important because more of the roof is visible from the street. Your roof can add or subtract from your home’s curb-appeal.

Roofing Materials Chart

Type	Description	Works For	Pros	Cons
Single-Ply Membrane	Sheets of plastic or rubber polymer fastened to the home mechanically and/or with adhesives. Some types must have an extra top coating to increase reflectivity. May be finished with gravel or stone for aesthetic reasons and to improve puncture-resistance.	Low-Slope	Highly waterproof; highly reflective; lightweight; assembled off-site; easy to repair; low to moderate cost.	Can be punctured; seams may require resealing every 5 years; variable lifespan (depending on specific type selected); may need additional insulation to improve cold weather performance.
Built-Up (Tar and Gravel)	A base sheet, covered with multiple layers of fabric or fiberglass, fused together with asphalt, and coated with a surface layer of gravel or other mineral material. May also be coated with a reflective coating to improve energy efficiency.	Low-Slope	Highly waterproof; highly reflective (depending on top layer); inexpensive; resilient; low-maintenance.	Short lifespan (10-25 years); installation is smelly; heavy.
Modified Bitumen	Single or (more often) multiple layers of plastic or rubber with a top reinforcement coat of granular mineral or a smooth cool coating, sealed with asphalt. May also be used to create a built-up roof.	Low-Slope	Waterproof; moderate cost, assembled off-site; light; low-maintenance; newer hot-air welding installation is safe, quick and clean.	Older, torch-down installation is a fire hazard during installation and adds expense.
Spray Polyurethane Foam Roofing	Polyurethane liquid is sprayed onto the roof and topped with a reflective coating.	Low-Slope	Highly waterproof; excellent reflective and insulating properties; can be applied over existing roof; can be layered to build additional slope and/or add insulation; moderate cost (additional layers add to cost).	Requires expert installation; requires regular inspection and recoating every 10-15 years.
Asphalt Shingle	Made from an organic (often paper) or fiberglass base saturated with asphalt and coated with mineral granules.	High-Slope	Good fire-resistance; inexpensive; easy installation; wide variety of colors; low maintenance.	Relatively low durability; short lifespan (15-25 years).
Tile	Made from clay or concrete, applied in an overlapping pattern. Glazing can add to waterproofing and reflective qualities.	High-Slope	Highly fire-resistant; eco-friendly; long lifespan (20-50 years); moderate cost; durable.	Heavy; individual shingles are breakable.
Slate Shingle	Natural or synthetic slate rock shingles.	High-Slope	Extremely durable, with a long lifespan (20-50 years); excellent fire-resistance; natural slate is eco-friendly.	Expensive; natural slate is heavy; individual shingles are breakable.
Metal	Metal roofs are generally made from steel, aluminum or copper, and may be painted or coated. Low-slope roofs must use metal structural panels, while high-slope roofs can use either panels or metal shingles.	Low- or High-Slope	Extremely watertight and fire-resistant; highly reflective; long-lasting; can be made from recycled materials; moderate cost.