NCCER Basic Carpentry & Framing 3 — Questions and Answers
Question 1: What is the purpose of a let-in brace in platform framing?
- To support floor joists at mid-span
- To provide diagonal racking resistance in a wall (Correct answer)
- To connect double top plates at corners
- To hold headers over openings
Correct answer: To provide diagonal racking resistance in a wall
A let-in brace is a diagonal board notched into the face of studs to resist lateral racking forces on a wall.
Question 2: The actual dimension of a 2x4 piece of lumber is:
- 2 inches by 4 inches
- 1-1/2 inches by 3-1/2 inches (Correct answer)
- 1-3/4 inches by 3-3/4 inches
- 2 inches by 3-1/2 inches
Correct answer: 1-1/2 inches by 3-1/2 inches
A nominal 2x4 actually measures 1-1/2 inches by 3-1/2 inches after milling and drying.
Question 3: When framing an interior non-load-bearing partition wall, the minimum stud size typically required is:
- 2x3 (Correct answer)
- 2x4
- 2x6
- 2x8
Correct answer: 2x3
Non-load-bearing interior partitions can use 2x3 studs, though 2x4 is more common for stability and utility chases.
Question 4: A carpenter uses a speed square to mark a rafter. The 'rise' number on the speed square represents:
- The total height of the roof
- The vertical rise per 12 inches of horizontal run (Correct answer)
- The rafter length per foot of span
- The pitch angle in degrees
Correct answer: The vertical rise per 12 inches of horizontal run
The rise number on a speed square indicates the vertical rise in inches for every 12 inches of horizontal run, defining the roof pitch.
Question 5: What is the purpose of blocking installed between floor joists?
- To increase the span capability of the joists
- To prevent joist rotation and provide lateral stability (Correct answer)
- To serve as a nailer for flooring only
- To reduce lumber quantity needed
Correct answer: To prevent joist rotation and provide lateral stability
Blocking between joists prevents rotation (twisting) and provides lateral bracing, improving the structural performance of the floor system.
Question 6: Which of the following best describes a flush beam in floor framing?
- A beam that runs along the top of the foundation wall
- A beam whose top surface is level with the top of the joists it supports (Correct answer)
- A beam installed below the joists it carries
- A beam used only in steel construction
Correct answer: A beam whose top surface is level with the top of the joists it supports
A flush beam has its top surface at the same level as the joists, allowing the floor sheathing to run continuously without a step.
Question 7: When installing roof sheathing, the panels should be oriented with the long dimension:
- Parallel to the ridge
- Perpendicular to the rafters (across them) (Correct answer)
- At a 45-degree angle to the rafters
- In any direction as long as nailed properly
Correct answer: Perpendicular to the rafters (across them)
Sheathing panels should span across (perpendicular to) the rafters so that panel edges land on framing members for proper support.
NCCER Basic Carpentry & Framing 3
What is the purpose of a let-in brace in platform framing?