According to the new span tables and irc provisions, cantilevers can extend up to one-fourth the backspan of the joist. This means that joists, such as southern pine 2x10s at 16 inches on-center, spanning 12 feet are allowed to cantilever up to an additional 3 feet (see illustration, below).
How Far Can a Balcony Cantilever?
A cantilever balcony is an architectural structure that projects from the side of a building, typically supported on one side only.
These balconies are typically constructed of steel or reinforced concrete and are designed to extend outward from the building, often providing a beautiful view and extra living space.
However, there are limits to how far a balcony cantilever can extend. The length of the cantilever balcony is determined by several factors, including the weight of the balcony, the load–bearing capacity of the supporting wall, the type of foundation, the wind load, and the seismic load.
Generally speaking, a cantilever balcony can extend up to four and a half feet past the building’s exterior wall. However, this distance can be restricted further due to local building regulations.
The weight of the balcony is one of the main factors in determining how far a balcony cantilever can extend. Balconies made from steel are typically heavier than those made from concrete, so they require more support and have a more limited cantilever length.
Because of this, it’s important to carefully consider the weight of the balcony when planning its length. The load–bearing capacity of the supporting wall is also a major factor in determining