Helical Stair Detailing Real Page Lakeside Helix Stair

Helical Stair Detailing Real Page Lakeside Helix Stair Presented By Bruce Vaughan

Real Page Lakeside Helix Stair

Helical Stair Definition and Setup • A helical or curved staircase does not have a central column setting it apart from spiral stairs. • 14’-0 floor to floor, 28 risers with intermediate landing, 6” risers • Outside stair – HSS 20 x 12 x 5/8 on 17’-7 and 13’-9 radius • Inside stair – HSS 20 x 8 x 5/8 on 11’-9 and 7’-8 radius

Helical Stair Setup

Helical Stair Setup Tread Plan Angle • Started the tread layout at the landing • Outside stair starting angle 15. 23° from grid 24 – 14 treads @ 7. 9686° (θ) • 13 treads plus full flush tread at floor • Inside stair starting angle 20. 00° from grid 24 – 14 treads @ 9. 0236° (θ) • 13 treads plus full flush tread at floor

Helical Stair Setup

Helical Stair Setup Rise Per Degree • Rise (in) / Plan Angle (°) – Outside stair • 6/7. 9686 = 0. 7530 in/° – Inside stair • 6/9. 0236 = 0. 6649 in/°

Helical Stair Setup Tread Run • Tread run = tread distance along arc at each stair beam centerline • In general: – Run = θ/(180/π)*r – r is the stair beam radius • Outside/outside: 29. 3455” • Outside/inside: 22. 9479” • Inside/outside: 22. 2063” • Inside/inside: 14. 3317”

Helical Stair Setup Slope On Arc • In general, the slope along the arc is calculated: – S = atan(6/Run) • • Outside/outside: 11. 5555° Outside/inside: 14. 6526° Inside/outside: 15. 1217° Inside/inside: 22. 7167°

Second Level Framing Plan

Framing Details

Framing Details

Framing Details

Framing Details

Framing Details

Framing Details

Framing Details

Guardrail Post Details

Guardrail Post Details

Guardrail Post Details

Questions? Bruce Vaughan bvdet@comcast. net For questions and comments, email or post to the SDS/2 Detailing Forum.