There are two types of walls used in a your home: load-bearing and non-load-bearing and as we start to dream of renovating our homes, adding an addition or building a whole new home, understanding the walls is key to fulfilling your dreams.
Load-bearing walls are the ones that support their own weight and some other structural elements such as joists, beams, girders or the floor above. The non-load-bearing walls create the rooms within your space but do not support any other element. They simply define the space.
Non-load-bearing walls that run perpendicular to the floor joists may be placed anywhere, but if placed parallel to floor joists, the wall must be supported by joists beneath it, or by blocking between the joists.
Structures employing load-bearing walls are one of the earliest forms of construction. Depending on the style of home, and whether it is a bungalow, two- or three-story home, the architect and structural engineer who draws your building plans will design load-bearing walls gauged to the appropriate thickness to carry the weight above them.
This is an important calculation since it is possible that a load-bearing wall could become volatile if the load exceeds the strength of the material used, and this could lead to a collapse.
Some building plans may not have any load-bearing walls inside the home. If you are using post and beam or steel girders, it is possible that all load-bearing walls will be the outside walls of the home. Exterior walls that carry ceiling, roof or upper floor loads to the foundation are load bearing or "bearing" walls.
Most often, the load-bearing walls are perpendicular to the joists they support. If two separate floor joists or ceiling joists intersect over a wall, that wall should be considered load-bearing.
Look at the beams and posts in your basement floor plan. In multi-floor dwellings, posts and beams in the basement indicate bearing walls above them, even up two floors. Be aware that these multi-floor bearing walls may not be directly above each other.
These posts and beams are incredibly important to the structure and integrity of your new home. Failure to provide proper support posts can lead to serious consequences, even the collapse of the floor above.
Inside the home, the internal walls that support joists at mid span and transfer loads down to foundations are also bearing walls. The walls of the lower floors hold up the roof and upper floors of your house. To support the entire house, these walls must be carefully located beneath upper level floor joists. There are a number of framing options for longer or stiffer span requirements that make the open spaces of contemporary home design possible.
Be sure to safely store the existing copy of your home's original building plans or if you have had to draw up a set in order to complete a renovation project. Down the road, if you decide to renovate yet another room or to sell the home to new owners who may wish to renovate, the original building plans will be extremely important in planning the renovation.