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Presentation 37:. STAIRWELL LENGTH AND HEADROOM. Stairwell Length and Headroom. A stairwell is the opening in a floor through which stairs are used. Its length depends on the unit rise and unit run of the stairs. Sufficient headroom must be maintained along the entire stair.
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Presentation 37: STAIRWELL LENGTH AND HEADROOM
Stairwell Lengthand Headroom • A stairwell is the opening in a floor through which stairs are used. • Its length depends on the unit rise and unit run of the stairs. • Sufficient headroom must be maintained along the entire stair.
Stairwell Lengthand Headroom Stairwell length • Headroom must be more than 6′- 8″ (80″). • The stairwell length is adjusted to maintain headroom. Headroom Unit Run Unit Rise
Stairwell length Stairwell Length • Gentle stairs need a longer stairwell length to allow for the headroom.
Stairwell Length Stairwell length • How many unit runs under the opening?
Stairwell Length Stairwell length • How many unit runs under the opening? • This number depends on the number of rises under the opening.
Headroom Headroom • Number of rises is related to the desired headroom.
Headroom Headroom Upper Construction • Number of rises is related to the desired headroom. • Note where the headroom is measured to on top. • Upper construction must be included with the headroom.
Stairwell Length Procedure • Add desired headroom to upper construction measurement. • Divide this number by the unit rise and round up. (This is # of unit runs). • Multiply this number by unit run.
12 ½″ 80″ 10 ½″ 7 ½″ Stairwell Length Calculation • Determine stairwell length if: Unit rise = 7 ½″ Unit run = 10 ½″ Headroom = 80″ Upper const. = 12 ½″
Calculation • Add headroom to upper construction. 80 + 12 ½″ = 92 ½″ total clearance • Divide by unit rise and round up. 92 ½″÷ 7 ½″ = 12.333 → 13 rises • Multiply by unit run. 13 x 10 ½″ = 136 ½″ Stairwell Length.
136 ½″ Stairwell Length Calculation • Stairwell length should be 136 ½″. 12 ½″ 80″ 10 ½″ 7 ½″
Conclusions • Headroom is typically more than 80″. • Stairwell length is determined from headroom, upper construction thickness, unit rise, and unit run.