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Stair Construction Flashcards

7 cards from real 403A practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Stair Construction flashcards as text
  1. What is the maximum unit rise permitted for interior stairs under the National Building Code of Canada?

    Answer: 200mm

    The NBC limits interior stair risers to a maximum of 200mm to ensure safe and comfortable climbing.

  2. A staircase has a total rise of 2,800mm and requires 14 risers. What is the unit rise?

    Answer: 200mm

    Unit rise = total rise ÷ number of risers = 2,800 ÷ 14 = 200mm.

  3. Which stair component directly supports the treads and risers along the sides of the staircase?

    Answer: Stringer

    The stringer (also called a carriage) is the structural inclined board that supports the treads and risers.

  4. What is the minimum unit run (tread depth) required for residential stairs under the NBC?

    Answer: 235mm

    The NBC requires a minimum tread depth (unit run) of 235mm for residential stairs to ensure safe foot placement.

  5. What is the minimum required headroom clearance for a staircase under the National Building Code of Canada?

    Answer: 1950mm

    The NBC mandates a minimum of 1950mm of headroom measured vertically from the nosing line to the ceiling above.

  6. Using the stair comfort formula 2 × Rise + Run = 635mm, what tread depth is required for a unit rise of 190mm?

    Answer: 255mm

    2 × 190 + Run = 635mm; 380 + Run = 635; Run = 255mm.

  7. What is the 'nosing' of a stair tread?

    Answer: The horizontal projection of the tread beyond the riser below

    The nosing is the portion of the tread that overhangs or projects beyond the face of the riser below it.

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Sources & references

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  1. red-seal.ca — Exam format, passing score, time limit · verified Oct 2026
  2. skilledtradesontario.ca — Eligibility, renewal, test delivery, fees, retake policy, retake fee · verified Oct 2026