1 presentation 37: stairwell length and headroom

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Presentation 37:

STAIRWELL LENGTH AND HEADROOM

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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.

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Stairwell Lengthand Headroom

Stairwell length

Hea

droo

mUnit Rise

Unit Run

• Headroom must be more than 6′- 8″ (80″).

• The stairwell length is adjusted to maintain headroom.

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Stairwell Length

• Gentle stairs need a longer stairwell length to allow for the headroom.

Stairwell length

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Stairwell Length

Stairwell length• How many unit runs under the opening?

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Stairwell Length

Stairwell length• How many unit runs under the opening?

• This number depends on the number of rises under the opening.

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Headroom

• Number of rises is related to the desired headroom.

Hea

droo

m

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Headroom

• Number of rises is related to the desired headroom.

Upper Construction

Hea

droo

m• Note where the headroom is measured to on top.

• Upper construction must be included with the headroom.

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Stairwell Length Procedure

1. Add desired headroom to upper construction measurement.

2. Divide this number by the unit rise and round up. (This is # of unit runs).

3. Multiply this number by unit run.

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Stairwell Length Calculation

• Determine stairwell length if: 12 ½″

10 ½″

7 ½″80

″

Unit rise = 7 ½″

Unit run = 10 ½″

Headroom = 80″

Upper const. = 12 ½″

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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.

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Stairwell Length Calculation

• Stairwell length should be 136 ½″.

7 ½″

10 ½″

12 ½″

80″

136 ½″

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Conclusions

• Headroom is typically more than 80″.

• Stairwell length is determined from headroom, upper construction thickness, unit rise, and unit run.