Supporting frameworks are structures that provide support for a building or other structure. The two most common types of supporting frameworks are trusses and trestles. A TRUSS is a framework consisting of rafters, posts, and struts, forming a rigid structure used to support a roof, bridge, or other structure. A TRESTLE is a framework consisting of a number of short pieces of timber or metal arranged in a sloping or stepped form, used as a support for a bridge or other structure. Both trusses and trestles are essential components of any supporting framework.