The load is transported from a slab to the beams, then to the columns, then to lower columns, and eventually to the foundation, which transmits it to the earth in an RCC-framed building. The walls of such constructions are built after the frame is complete. The frame is first covered with sheathing and then with panels or boards. The floor may be made of wood planks or tiles.
In steel frame construction, the structural members of the frame are often exposed during construction of the building interior. They may be used as internal support for floors, ceilings, or walls. They may also be left exposed as part of the intended design appearance. In either case, these members must be well-supported by other components of the building envelope if they are to serve their purpose effectively.
In concrete frame construction, the exterior wall is usually the primary source of support for the roof. The roof is built on top of the wall, and so provides an additional load-bearing surface. However, because the roof is not tied directly into the floor system, care must be taken to provide sufficient support at the perimeter of the building to prevent sagging.
In timber frame construction, the main method of supporting the roof is through the use of purlins attached to the front of the house under which rafters protrude. The ends of the rafters are then joined to the side walls using long horizontal trusses called girts.
Floor loads are often carried from slabs to beams, and from the beams to columns in the design of reinforced concrete buildings. Finally, the columns convey the superstructure weight to the structure's base. The depth of the slab determines the amount of stress that can be placed on any one beam or column. The deeper the slab, the more stress that can be carried by these elements.
Beams connect floors together in buildings. They may be straight or curved, depending on the desired appearance for the building. Beams must be strong enough to carry the expected floor loads as well as the load of any additional structures that might be attached to them. The size of the beam depends on the application; typical sizes range from about 2 feet (60 cm) deep by 6 inches (152 mm) wide at the face of the slab to about 12 feet (370 mm) by 36 inches (914 mm) for large support beams in high-rise buildings.
Columns are tall, slender structural members used to support heavy roofs or walls. Columns should be designed so that they can bear the anticipated load without breaking under normal conditions. The size of the column depends on the application; typical sizes range from about 3 inches (75 mm) diameter at the base of the shaft to about 18 inches (45 cm) diameter at the top of the pillar.
A beam, column, and foundation support the entire weight of a building or structure in a frame construction. Beams are joined to columns, and columns are connected to footing foundations. The footing safely transfers the weight from the beam to the column, then to the footing, and ultimately to the earth. The connection between the beam and the column is called a framing member. The most common framing members are cross-ties for wood frames and steel posts for concrete frames.
The beam is attached to the column at their intersection using a framing member called a header. The header transmits the load from the beam to the column across their respective faces. If the beam and column were simply fastened together, then all the force would be transmitted through this joint, causing both items to fail simultaneously. By attaching the beam to the column with a header, the two items will fail separately - the beam will collapse before the column does. The header also provides space for any required shear movement between the beam and the column. For example, if the column is fixed while the beam expands or contracts as it gains or loses moisture, the header allows for this motion without failure. Finally, the header protects the column from being hit by debris when the beam is repaired or replaced.
When a beam is not attached to a column, but rather rests on top of several supporting joists (called "stringers" in the U.S.), it is called a gable beam.