403A Framing 2 — Questions and Answers
Question 1: What is the standard dimensional lumber size for a 2x6 stud after dressing (surfacing)?
- 2 inches × 6 inches
- 1-1/2 inches × 5-1/2 inches (Correct answer)
- 1-3/4 inches × 5-3/4 inches
- 1-1/4 inches × 5-1/4 inches
Correct answer: 1-1/2 inches × 5-1/2 inches
Dimensional lumber is smaller than its nominal size after kiln drying and planing. A nominal 2×6 measures 1-1/2 inches (38 mm) by 5-1/2 inches (140 mm) in actual dimensions.
Question 2: What is the function of blocking installed between floor joists?
- To support plumbing lines
- To prevent joist rotation and distribute concentrated loads (Correct answer)
- To increase the floor joist span
- To provide ventilation between joist bays
Correct answer: To prevent joist rotation and distribute concentrated loads
Blocking (or bridging) between floor joists prevents the joists from twisting or rotating under load and helps distribute concentrated loads to adjacent joists, improving the overall floor system performance.
Question 3: In balloon framing, how do wall studs differ from platform framing?
- They are spaced at 24 inches on centre
- They run continuously from the sill plate to the roof line (Correct answer)
- They are made from engineered lumber only
- They use metal connectors instead of nails
Correct answer: They run continuously from the sill plate to the roof line
In balloon framing, studs run the full height of the building from the foundation sill plate to the roof. This differs from platform framing where studs are only one storey high.
Question 4: What is the purpose of a trimmer stud (jack stud) in a framed wall opening?
- To add bracing above the opening
- To support the header directly and transfer its load to the bottom plate (Correct answer)
- To frame the sill of a window opening
- To provide a surface for attaching door hardware
Correct answer: To support the header directly and transfer its load to the bottom plate
Trimmer studs (jack studs) are installed alongside king studs and directly support the header above a door or window opening, transferring the load from the header down to the bottom plate and foundation.
Question 5: What SPF lumber species group is most commonly used in Canadian residential framing?
- Douglas Fir-Larch
- Hem-Fir
- Spruce-Pine-Fir (Correct answer)
- Northern Species
Correct answer: Spruce-Pine-Fir
Spruce-Pine-Fir (SPF) is the most commonly used species group for framing lumber in Canada due to its availability, workability, and adequate structural properties for residential construction.
Question 6: When framing a gable end wall, what determines the angle of the top plate cuts?
- The width of the building
- The roof pitch (Correct answer)
- The wind load requirements
- The type of sheathing used
Correct answer: The roof pitch
The roof pitch directly determines the angle at which the top plates of a gable end wall must be cut. The studs increase in length progressively to match the roof slope.
403A Framing 2
What is the standard dimensional lumber size for a 2x6 stud after dressing (surfacing)?