Once a foundation is installed, then framers begin to build the structure of the house. If the house is on a slab foundation, the framers start by erecting the walls. However, if the house is built on a crawl space or basement as are most stick built homes in Washington State, then framers first need to begin by building the floor.
The floor starts with a sill-plate made of pressure-treated lumber that is bolted to the crawl space wall. Then the floor is constructed on the sill with either 2” x 10” lumber called ‘joists, or an engineered products called “I-Joists”. The joists are hung either using a Rim Joist or Hung Joist floor system. These will be discussed in more detail in a future article.
Once the joists have been installed, either plywood or OSB (oriented strand board) that are laid down over the top of the joists and the floor is finished.
Exterior walls are built using 2 x 6 lumber placed “16-inch on center” apart, meaning that the center of one 2 x 6 is 16 inches away from the center of the next. True Built Home uses true 8′ ceilings
In this wall, two things interrupt the consistent 16-inch pattern:
The plywood will be cut out to form the opening for the window. On each side, the main 2” x 6” is placed called a King stud. Another 2” x 6” called a Trimmer will be cut for the window sides. At the base is a sill which the window will sit on. At the top above the window is a header. The header is usually a 6″ x 8″ or 6″ x 10″ which carries the load from the roof above to the trimmer studs. This effectively transmutes the weight of the roof to the ground around the window so that the window doesn’t shatter under the pressure of gravity. You will see these headers over all windows and doors — they give the wall enough strength over the window or door to support the roof.
Exterior walls are insulated to keep heat from escaping and also to diminish street noise from the inside. Interior walls are typically not insulated unless there is a need for sound muffling between rooms. This could be the case for example if a bedroom borders a living room. In a case like this, insulation can help muffle the noise of a television while someone is trying to sleep. As for heat retention, insulating interior walls has little value.
The walls of the garage are built slightly differently (because the garage will have a slab floor instead of a crawl space). Often, since garages are not considered living space and so do not require insulation, the walls of the garage are built with 2 x 4 studs instead of 2 x 6’s. The walls are bolted directly to the foundation walls