Technical Measurements Flashcards
7 cards from real CBI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Technical Measurements flashcards as text
Under the IRC, what is the maximum allowed difference between the tallest and shortest riser within a single flight of stairs?
Answer: 3/8 inch
IRC R311.7.5 limits riser and tread variation within a flight to 3/8 inch.
A stairway has a total rise of 108 inches. What is the minimum number of risers needed to comply with the IRC maximum riser height of 7-3/4 inches?
Answer: 14
108 ÷ 7.75 = 13.9, so 14 risers are required, giving about 7.71 inches each.
What is the minimum headroom required above stair treads in a dwelling under the IRC, measured vertically from the sloped plane of the tread nosings?
Answer: 6 feet 8 inches
IRC R311.7.2 requires a minimum stair headroom of 6 feet 8 inches.
Required handrails on residential stairs must be installed at what height range, measured vertically from the sloped plane of the tread nosings?
Answer: 34 to 38 inches
IRC R311.7.8.1 sets handrail height between 34 and 38 inches above the nosings.
What is the minimum clear space required between a handrail and the adjacent wall?
Answer: 1-1/2 inches
Handrails must have at least 1-1/2 inches of clearance from the wall to allow a proper grip.
A Type I circular handrail must have an outside diameter within which range?
Answer: 1-1/4 to 2 inches
IRC R311.7.8.5 requires a circular handrail diameter of 1-1/4 to 2 inches.
The triangular opening formed by the riser, tread, and bottom rail of a stair guard must not allow passage of a sphere of what diameter?
Answer: 6 inches
IRC R312.1.3 permits that triangular opening as long as a 6-inch sphere cannot pass.