Roofing Terminology

Whether it is a point of architectural interest or a feature that blends into its exterior, the roof of your home provides substantial protection against the elements. It keeps all the structural components dry, helps control energy bills and shelters everything below it.
Although a roof lasts many decades, they do need periodic attention and maintenance. When you need to talk to a professional for any kind of roofing project, it’s helpful to know the language.

Structural Components

The roof’s structural components include the framework that supports the roofing material and everything just below it.

  • Roof Deck. Usually made from plywood and covered with asphalt-impregnated paper, the roof deck covers the trusses and provides a surface to which the roofing materials are applied.
  • Trusses. Roof trusses form the upper support for a roof. The two main types include scissor trusses and cantilevered trusses. Cantilevered trusses provide more head space for walking in the attic than scissor trusses that meet in the center and descend at angles to the outside walls.
  • Rafters. Less common than they used to be, rafters’ function just like trusses and are built on-site by carpenters instead of in a factory.
  • Joists. Joists form the underlying support for the attic floor. They span one side of the home to another. They are also used in multi-story homes to support the floors.
    Soffits. These overhangs are used for architectural interest and shade. They extend beyond the roof line and the trusses or rafters are enclosed with wood.
  • Eaves. The eaves around the place where the roof meets the tops of the exterior walls wrap the house and seal the edges. Gutters are often attached to the eaves to carry away rainfall.


All roofs require ventilation to prevent moisture condensation and thermal buildup.

  • Ridge vents lie along the top center beam of the roof and let the hot air escape.
  • Soffit vents are placed on the undersides of soffits that form an overhang. They are covered with some type of mesh or louvers to keep small animals from entering the attic.
  • Gable end vents are built into the vertical ends of an exterior wall near the peak of the attic.

Roofing Materials

  • Coatings. You’ll find foam or elastomeric paint coatings on flat roofs that are waterproof and insulating. They are either sprayed or rolled on, and usually white. Both are durable, but they do degrade over time and if not recoated or repaired, will leak.
  • Shingles. The most common roofing shingle is made from asphalt and covered with granules. Architectural shingles are heavier than tab shingles and last longer. Shingles are placed over an underlayment.
  • Wooden shingles have been used in the Bay area but require a good deal of maintenance and pose a fire hazard. An option for people who like the look of wooden, or shake shingles, is to use fiber-cement shake shingles, but do not require the maintenance and will not burn.
  • Tiles. Made from masonry products, tile roofs are common in the Bay area for good reason. They last for decades, are attractive and blend well with the architecture of the region. They weigh more than any other type of roofing material and putting them on a roof not designed for them will require structural reinforcement.
  • Metal Roofing. The most durable of all roofing products, metal roofs are lightweight and energy efficient. They’re available in a variety of colors and styles and require little maintenance.
These basic roofing terms will help you discuss your roof with a professional. It is important to pay attention to the condition of the roof because it safeguards the integrity of your entire home.