When framing a multi-story home there are two choices of construction techniques - platform or western framing and balloon framing.
Platform framing is the most common of the two construction methods used today for multi-story residential home construction.
As the name implies, a platform, the floor, is first constructed over the foundation. Walls are then erected to the height of the second story, where a second platform, second story floor, is constructed. Walls for the second story are then added and if their is a third story, a platform, third story floor is built.
Figure 1 shows basic multi-story platform wall construction and Table 1 shows the associated structural components.
Figure 1 - Platform multi-story house framing
Structural Components of Platform Multi-Story House Framing
- A - 1st Floor - Floor Joist
- B - 1st Floor - Sub-Floor
- C - 1st Floor - Bottom Wall Plate
- D - 1st Floor - Wall Stud
- E - 1st Floor - Upper Wall Plate
- F - 1st Floor - Top Wall Plate
- G - 2nd Floor - Floor Joist
- H - 2nd Floor - Sub-Floor
- I - 2nd Floor - Bottom Wall Plate
- J - 2nd Floor - Wall Stud
- K - 2nd Floor - Upper Wall Plate
- L - 2nd Floor - Top Wall Plate
From a construction standpoint, platform house framing is much easier, and hence, less labor intensive than balloon house framing.
- The walls can be conveniently built on the floor and then raised into position.
- It is much easier to locate the placement of windows and doors.
- Smaller lengths of lumber ( 2 x 4) are less expensive.
- Separation between floors acts as a fire stop.