403A Blueprint Reading & Layout 4 — Questions and Answers
Question 1: What is the function of batter boards during foundation layout?
- To establish and maintain building line positions above the excavation (Correct answer)
- To support concrete formwork during pours
- To brace wall framing during erection
- To hold reinforcing steel in position
Correct answer: To establish and maintain building line positions above the excavation
Batter boards are horizontal boards nailed to stakes set back from the building corners. String lines stretched between saw kerfs in the boards establish the exact building lines above the excavation and can be replaced after digging without re-measuring.
Question 2: How is the total rise of a staircase calculated from a drawing?
- By measuring from finished floor to finished floor vertically (Correct answer)
- By measuring the length of the stringer
- By counting the number of treads and multiplying by tread depth
- By measuring the rough opening height
Correct answer: By measuring from finished floor to finished floor vertically
Total rise is the vertical distance from finished floor level at the bottom to finished floor level at the top. This dimension drives all stair calculations — number of risers, individual riser height, and stringer length.
Question 3: On a structural drawing, 'W250×89' refers to what type of structural member?
- A wide-flange steel beam approximately 250 mm deep weighing 89 kg/m (Correct answer)
- A wood beam 250 mm wide and 89 mm deep
- A concrete column 250 mm square with 89 MPa strength
- A wall section 250 mm thick at 89 MPa
Correct answer: A wide-flange steel beam approximately 250 mm deep weighing 89 kg/m
W-sections are wide-flange steel beams. W250×89 means approximately 250 mm nominal depth and 89 kilograms per linear metre. These designations follow the CISC standard for Canadian structural steel.
Question 4: A floor plan shows a window symbol with the number '2440×1220' beside it. What do these numbers represent?
- Width × Height in millimetres (Correct answer)
- Height × Width in millimetres
- Rough opening width × height in inches
- Glass size in centimetres
Correct answer: Width × Height in millimetres
Canadian drawing conventions typically express window sizes as width × height in millimetres. This window is 2440 mm wide and 1220 mm tall. Always verify the drawing legend as conventions can vary.
Question 5: What does a solid triangle symbol pointing to a wall on a floor plan typically indicate?
- The direction of an interior elevation reference (Correct answer)
- A structural bearing point
- A plumbing cleanout location
- A fire-rated wall assembly
Correct answer: The direction of an interior elevation reference
A solid triangle or arrow on a floor plan pointing toward a wall references an interior elevation drawing. The number or letter inside identifies which elevation sheet shows that wall's interior detail.
Question 6: In Canadian metric construction drawings, what does 'GL' indicate in window and door schedules?
- Glass or glazing size (Correct answer)
- Ground level
- Grade line
- General labour item
Correct answer: Glass or glazing size
In window and door schedules, 'GL' typically refers to the glass or glazing unit size — the actual glass dimensions, which are smaller than the frame or rough opening size.
403A Blueprint Reading & Layout 4
What is the function of batter boards during foundation layout?