A load-bearing wall
or bearing wall
, is one in which a wall of a structure
bears the weight and force resting upon it, conducting the vertical load from the upper structure to the foundation. A bearing wall is opposed to a curtain wall
, which uses the strength of a sub-wall to bear the weight of the curtain such as the brick facade on a skyscraper, and superstructure
, usually a steel frame, to carry the weight of the floors and walls inside the curtain walls protection. The materials most often used to construct load-bearing walls in large buildings are concrete
, block, or brick
Load-bearing walls are one of the earliest forms of construction
. With the advent of Gothic architecture
, and its vast expanses of windows and high vaulted ceilings, flying buttresses
were employed to keep the weight of the building properly distributed. Notre Dame Cathedral
has a load-bearing wall structure with flying buttresses.
The birth of the skyscraper era, the concurrent rise of steel as a more suitable framing system, and the limitations of load-bearing construction in large buildings led to a decline in the use of load-bearing walls in large-scale, commercial structures.
Depending on the type of building and the number of stories, load-bearing walls are gauged to the appropriate thickness to carry the weight above it. Without doing so, it is possible that an outer wall could become unstable if the load exceeds the strength of the material used, potentially leading to the collapse of the structure.
In housing, bearing walls in the most common light construction method "platform framing
", each sit on wall sill plates
which are mated to the lowest base plates
, the two together making up a double width 2 x 4 or 2 x 6 laid horizontally atop one another, where the sills are bolted to the masonary
or concrete foundation
, and the base plate
or floor plate
is the bottom attachment point of wall studs
which rest upon it when the wall is laid up in place. Using a top and bottom plate, walls can be constructed laying down allowing end nailing then tipped up into place. The wall studs are end nailed between two plates, the top plate
or ceiling plate
being the name of the one just below the platform of the next floor (at the ceiling). Use of a top and bottom plate, enables walls to be constructed in a section along flat ground or on pavement, then tipped up into place atop the wall sill, improving accuracy and shortening the construction while providing a stronger wall.