The reciprocal frame is a roof structure where each beam both supports and is supported by other beams in the roof structure. A minimum of 3 beams is required to create a reciprocal frame roof. As each beam supports the next in a reciprocal manner no internal support structure is required. Only the outer end of each beam requires support which will normally be a post used for the wall. The roof loads are transferred to these posts and in turn to the supporting foundation. The beams can be fabricated from timbers, laminated wood, steel or reinforced concrete. A very inexpensive roof structure can be made from logs.