Below we’ll walk you through six generic classifications of steep-slope roof materials to help as you discuss your options with your contractor.
But before we get into the roof coverings, we need to discuss the underlayment.
Steep-slope roofing need to use an underlayment, which is fabric material applied to the roof’s surface prior to installation of the primary covering. This material provides additional protection to the roof, but is not directly exposed to the elements.
They are generally comprised of organic felts, glass fiber mats, composites or modified bitumen sheets. They are also either mechanically fastened (most common) or self-adhered (common when used for ice dam protection) to the roof.
Underlayment sheets must adhere to the following ASTM standards:
Asphalt shingles are made up of several layers:
The most common type of shingle is a strip shingle, which is 12-in. x 36-in., and includes three or four exposed tabs. These tabs can be separated from each other, one continuous piece (called non-cutout strip shingles), or randomly distributed (called random tab strip shingles).
These shingles can also come in a single layer, or with two or more layers. The latter are called laminated strip singles or architectural shingles.
Asphalt shingles must meet the following ASTM standards:
There are two main types of roofing tiles: Clay and Concrete.
Tiles are available in a variety of profiles, styles, finishes and colors, and textures can be applied.
Clay tiles must meet the following ASTM standards:
As the name would imply, fiber-cement shingles are made of cement and reinforced fibers. They are designed to serve as substitutes for wood shingles and shakes, slate, and tile in steep-slope applications.
They are made to look like and simulate these materials, and in most cases are installed in a similar fashion. However, they may not perform as well.
Fiber-cement coverings must meet the following ASTM standards:
There are two general types of metal roof systems: architectural and structural. Architectural metal possess water-shedding qualities, making it ideal for steep-slope roofing systems. See flat-roof materials for more information on structural metal.
Architectural metal can be categorized into the following:
Solid roof sheathing or decking is required for this roofing system.
Slate is a dense, durable, naturally occurring material that is essentially nonabsorbent.
The surface texture of slate is determined by the rock from which it was quarried. Some will appear smooth, while others are rough and uneven. The color and the degree to which the color changes after exposure to weather will also vary based on the rock used.
There are three classifications of slate:
Slate must meet the following ASTM standards:
Made of Western red cedar, cypress, pine and redwood trees, wood steep-slope roofing materials are available in shakes and shingles.
It’ll be important to consult with your roofing contractor on the best steep-slope roofing system for your building and the environment it will be exposed to. For example, level of protection, weather resistance and aesthetics all need to be taken into account.
It's all in this free ebook, The Building Owner's Guide to Roofing. In it, you'll learn how to select the best contractor, roofing membrane and warranty for your needs. Download it today.