Beginning around 1915 most homes have been built using a wood frame construction system. The system consists of wood wall studs, and wood floor joists. Wood is also used to frame the roof and other bracing as needed.
Even homes with brick or stone exteriors are first framed with wood before the application of the external materials. The very heart of the system is the wood wall framing. These walls support the roof and divide the interior space into functional rooms – kitchen, bathrooms, bedrooms, etc.
Wall Framing Basics
There are two basic house framing schemes: balloon framing and platform framing. This only relates to houses of more than one story in height. With balloon framing, the studs forming the external walls go all the way up to the roof.
On the other hand, with platform framing, the first floor is built as normal but instead of setting roof trusses on the walls, second floor floor joists are set and then the second floor exterior walls are built. The terms are self explanatory.
The three parts to framing a wall are the vertical studs, and the top and bottom plates. The top plate is generally continuous while the bottom plate is discontinuous at doorways and case openings.
Where this occurs, a horizontal header bridges the gap and small sections of studs are inserted between the header and the top plate.
Exterior Wall Framing
The exterior walls are the first to be built and for many reasons they are the most important. For one thing, they are the end supports for the roof trusses and in some cases the second floor floor joists. Also, these walls will be the ones to bear the brunt of the weather such as storms or hurricanes. They must also be energy efficient.
Traditionally, these exterior walls were framed with 2′ X 4′ studs, like the interior walls but lately some builders have been using 2′ X 6′ studs. The extra depth affords more strength and more space in which to insert insulation. The walls are framed either on 16 inch centers or 24 inch centers although 16 inches is the most common.
The exterior walls are framed laying down on the slab or foundation and then stood up, plumbed, braced, and nailed together. Care must be taken when laying them out so that the windows, doors, etc., will be in the correct places and of the correct sizes.
Interior Wall Framing
Once the exterior walls are done, work on the interior walls can begin. Often this is done in conjunction with drying in the exterior with tyvek and sheathing. Another crew will be busy setting the roof trusses if they are pre-fabricated or framing the roof from scratch.
Interior walls are built using 2′ X 4′ studs, generally on 16 inch centers. Interior walls may be framed with metal studs as commercial walls are but for some reason this method of how to frame a wall has not totally caught on.
It does seem as though it would be advantageous. Some things should be done before the walls are built. For example, large items such as bathtubs should be, if not installed, at least in the bathroom for obvious reasons.
Interior walls that are built perpendicular to roof trusses or upper floor joist are of particular importance. They are referred to as load bearing walls and that is what they do – help bear the weight of everything above them. This is critical knowledge during future remodeling projects.