Framing & StructuralQuestion 380 of 700
For a dwelling stairway, what is the MINIMUM tread depth (run) required, measured horizontally between the leading edges of adjacent treads?
a.9 inches
b.10 inches
c.11 inches
d.12 inches
Explanation
The residential code requires a minimum tread depth of 10 inches for dwelling stairs. 9 inches is below the minimum and would be too steep; 11 and 12 inches exceed the minimum and are acceptable but not the required floor value. The commercial code requires a deeper 11-inch tread.
Law Reference: 2025 CA Residential Code §R311.7.5Practice all 700 questions free — no signup required.
Related questions on this topic
- When installing tongue-and-groove wood structural panel subflooring, which practice BEST reduces squeaks and improves diaphragm performance?
- A gable roof has a total run of 12 feet (horizontal from wall to ridge) and a slope of 6:12. Ignoring ridge and overhang, what is the approximate line length of a common rafter along the slope?
- Under the residential code, what is the MAXIMUM permitted riser height for a stairway serving a dwelling?
- Guards on open sides of walking surfaces in a dwelling must be at least what height above the walking surface or, for stairs, the line connecting the tread nosings?
- A required stair handrail must be mounted so its top is within what vertical range above the tread nosings?
- For a conventionally framed wall anchored to a concrete foundation, anchor bolts of at least 1/2-inch diameter must generally be spaced no more than what distance on center?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against California CSLB General Building (B) Trade Examination · How we review