diagram of a roof

The typical residential roofing system is made up of several components.

  1. Deck or Sheathing. This is the plywood or other sheet material that is fastened to the roof rafters to cover your home's structure. The roofing materials are applied to this sheathing.
  2. Roof Structure. The structure is composed of rafters, which make up the basic framework, as well as other engineered components, known as trusses, that support this framework. The roof structure is what supports the sheathing.
  3. Roof Covering. Various types of roofing materials are used in the covering, such as shingles, tiles, or metal. There is also an underlayment that protects the sheathing from weather.
  4. Flashing. This is the sheet metal or other material installed into a roof system's joints, pipes and intersections in order to prevent water seepage.
  5. Drainage. The roof's ability to shed water is the drainage system, which is part of the roofs design. This includes the shape, slope, and layout of the roof.
  6. Fire Rating. There is a system for classifying the fire resistance of various materials used in roofing. Roofing materials are rated Class A, B, or C, with Class A materials having the highest resistance to fire. Be aware of the fire ratings when choosing the material for your roof.
  7. Ventilation. Proper ventilation and insulation will affect the longevity of your roof. Without proper ventilation and insulation, heat can build up beneath the roof, causing the sheathing and shingles to rot or deteriorate prematurely. Proper ventilation is more important than the specific type of ventilation used. Whether it's ridge vents, box vents, turbines, or anything else, each can do a good job if properly matched up with the roof.