Terms of the Trade: What Is a Rafter? Terms of the Trade: What Is a Rafter?
A rafter is a vertical beam, usually with a slope, that supports a building's roof; any building with a roof likely has rafters. Resting on a supporting wall, the weight of the roof is transferred through the rafter down to the building's foundation. They are usually made of wood, but depending on the building's architecture can also be made from concrete or steel.