Roof Components 101

The roof is arguably the most fundamentally important aspect of any building, residential or commercial. Without the roof there exists no structural integrity nor protection from the elements. In fact, a building could hardly be referred to as such if there is no roof to the structure. The most temporary lean-to and the most extravagant mansion both have one thing in common: a roof. A proper roof is more complicated than it appears to the untrained eye. What looks to be a simple building element, much like just another wall, is actually made up of a number of important components; all of which are vital to its protecting function. Major components of any functional roof include:

• The truss - Basically, the truss is the supporting frame of the roof itself. 
• Rafters - The rafters are beams that run from the top of the roof to the bottom. They complete the framework of the roof.
• Decking or Sheathing - The panels on which the roofing materials are attached that cover the rafters. 
• Underlayment - An additional layer of moisture protection installed on top of the decking.
• Drip edge - Edging at the end of the roof that moves moisture away from the underlayment. 
• Fascia - Trim that covers the rafter ends of eaves. Gutters are often attached to the fascia trim.
• Soffit - The finished underside of the eaves.
• Flashing - Roof flashing is found at intersections and projections of a roof. Metal flashing helps prevent water from seeping into the roof itself. Flashing pieces are used around vent pipes, chimneys, valleys and joints.