Blueprint Reading & Layout Flashcards

What is the function of batter boards during foundation layout?

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.

How is the total rise of a staircase calculated from a drawing?

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.

On a structural drawing, 'W250×89' refers to what type of structural member?

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.

A floor plan shows a window symbol with the number '2440×1220' beside it. What do these numbers represent?

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.

What does a solid triangle symbol pointing to a wall on a floor plan typically indicate?

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.

In Canadian metric construction drawings, what does 'GL' indicate in window and door schedules?

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.