Ensure adequate 80-inch vertical clearance along the entire stair flight. Learn how to calculate the required ceiling opening length in upper floors.
S
Sarah Jenkins, Code Compliance Officer
Carpentry & Construction Author
Building codes require a minimum continuous headroom of 80 inches (6 feet 8 inches) measured vertically from a plane parallel to the sloped line connecting all tread nosings.
When framing the stairwell opening in the floor above, improper sizing can force tall occupants to duck. Calculate opening length by projecting the angle of the stair against the floor joist assembly thickness.
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