What Are the Parts of a Roof?
Photo credit: National Contractors

When it comes time to talk to a contractor about doing a residential roof repair or replacement, it's good to know the various parts of a roof and the components of a roofing system.

Photo Credit: GAF

Important Structural Components Below the Roof

Much of what can't be seen from the ground goes into supporting a roof. Here are parts of the roof that make up its underlying structure:

  • Rafters: A structural framing component that runs from the ridge, or peak, of the roof to the eave, or edge. Rafters form the base of a roof's support from inside the home.
  • Roof truss: A structural member or framework made up of three or more pieces, usually in the shape of a triangle. They support the roof decking and structure.
  • Decking/sheathing: The structural base of the roof that the roofing components are installed over and secured to. Decking or sheathing is usually made from plywood, OSB (oriented strand board) or wood plank. Along with the roof's structural framework, it is designed to support the load of the roofing system, snow load, and any other loads required by local code.
  • Eave: The lower horizontal roof edge of a sloped roof. The eave can also refer to the underside overhang of the lower horizontal roof edge from the fascia to the structure's outside wall.
  • Fascia: The board nailed to the end of the trusses or rafters at the edge of a roof. Fascia are made of wood or can be composite boards, which combine wood and plastic. Gutters are usually hung from the fascia.
  • Rake: The inclined edge of gable-style roof planes. A gable-style roof has two sloping sides that meet at the top.

The Roofing System

The roofing system consists of various components that help protect your home from the elements.

  • Ice & Water Shield (Leak Barrier): A self-adhered waterproof underlayment typically installed on top of the roof deck at the eave edge of the roof, as well as other vulnerable areas. This helps protect against leaks caused by wind-driven rain and ice dams.
  • Roof deck protection: Asphalt-saturated felt or a synthetic material that helps protects a home. It provides a water-shedding secondary layer of protection between the shingles and roof deck to prevent wind-driven rain from infiltrating.
  • Starter strip shingles: The first course of roofing installed at the eave and/or rake edges of a shingle roof to improve wind resistance.
  • Shingles: Roofing material typically made of asphalt, fiberglass mat and ceramic coated granules. Shingles serve as the primary roof covering and are installed in overlapping layers to protect the structure and help ensure proper water-shedding.
  • Ventilation: A balanced system of intake and exhaust vents that allow air to continuously flow through the attic space to exhaust excess heat and moisture.
  • Hip and ridge cap shingles: Shingles that are designed to be installed over the ridge and hip areas of the roof where two roof planes meet.

Factors to Consider when Selecting a Roofing System

There are numerous factors to consider when deciding what roofing materials to choose for your roofing project. You'll receive guidance from your governing documents, engineer or contractor on the types of materials that will be best for your home, but here are some key factors to take into consideration.


In most cases, asphalt shingles are going to be the most economical choice for your residential roof. If you are interested in a different aesthetic, or live in certain regions, you may want to consider other roofing material options, like slate, tile, wood shakes, or metal.

Warranty Terms

The standard manufacturer's warranty on asphalt shingles will last for anywhere between 20 years to "Lifetime." However, you should always be sure to review the specific terms of the warranty before making a final decision, as the specific coverage will vary significantly. You may also consider asking your contractor about the availability of enhanced warranties, which may provide longer or more comprehensive coverage than the standard manufacturer's warranty.

Maintenance and Repairs

Most residential roofing systems are minimal maintenance; however, you will want to inspect your roof at least twice a year and after significant weather events to look for damage or necessary repairs.

Whether you're in need of a complete replacement or a few repairs, always consult with the experts at National Contractors when considering a change to your roofing system.

Now that you know the basic parts of a residential roof, you'll be better able to discuss your options and select the best roof system to protect your home.

We are certified by GAF with the training and licensing to get your repair(s) done correctly. We are an industry leader offering unsurpassed general construction services to community associations, condominiums, management companies, engineering firms, residential and commercial property managers. When you hire National Contractors, you’re getting the best in the business.

Article & Image Courtesy of Dawn Killough for GAF

Roof Parts