STAIR SAMPLE CALCULATION

1
Presentation 38

• STAIR SAMPLE CALCULATION

2
Sample Stair Calculation

• Given

• Upper Const. 11 ¼?
• Floor to ceiling 8'-0?
• Headroom 80?
• Unit Run 10 ¾?

3
Sample Stair Calculation

• Find

• Total rise
• of risers
• Unit rise
• Stairwell length

4
Total Rise

• Total rise

8'-0? 11 ¼? 107 ¼?
5
Number of Risers

• of risers

107 ¼? 8 13.406 ? 14 or 15 risers
6
Unit Rise

• Unit rise

107 ¼? 14 7.66? 7 11/16? 107 ¼? 15
7.15? 7 1/8?
107 ¼?
7
Unit Rise

• 17 to 18 Rule

Unit Rise 7 1/8?

• Since unit run is 10.75?
• Best unit rise
• 10.75 7.66 18.41 or
• 10.75 7.15 17.90
• 7.15 is the better choice since 17.90 is between
  17 and 18.

11 ¼?
107 ¼?
8'-0?
15 risers
8
Stairwell Length
Unit Rise 7 1/8?

• Stairwell length

• 80? 11 ¼? 91 ¼?
• 91.25? 7.15 12.1667
• 13 treads in opening
• 13 x 10.75 139.75?

107 ¼?
15 risers
9
Conclusion
Unit Rise 7 1/8?

• Find

139 ¾?
107 ¼?

• Total rise
• of risers
• Unit rise
• Stairwell length

15
7 1/8?
107 ¼?
139 ¾?
15 risers