Open risers for spiral stairway

[Mr. Inspector]

Can somone help me to find a section for requirements for open or closed risers for a spiral stairway in the 2018 IBC? It is in a dwelling unit in a R2 apartment building which it is allowed to be used as an means of egress from a small mezzanine.

 

[ICE]

This is 2020 LA County Building Code based on 2018 IBC

1011.5.5.3 Solid risers. Risers shall be solid.
Exceptions:

1. Solid risers are not required for stairways that are not required to comply with Section1009.3, provided that the opening between treads does not permit the passage of a sphere with a diameter of 4 inches (102 mm).
2. Solid risers are not required for occupancies in Group I-3 or in Group F, H and S occupancies other than areas accessible to the public. The size of the opening in the riser is not restricted.
3. Solid risers are not required for spiral stairways constructed in accordance with Section1011.10.

1011.10 Spiral stairways. Spiral stairways are permitted to be used as a component in the means of egress only within dwelling units or from a space not more than 250 square feet in area and serving not more than five occupants, or from technical production areas in accordance with Section410.5.

A spiral stairway shall have a 6-3/4-inch minimum clear tread depth at a point 12 inches from the narrow edge. The risers shall be sufficient to provide a headroom of 78 inches minimum, but riser height shall not be more than 91/2 inches. The minimum stairway clear width at and below the handrail shall be 26 inches.

 

[patrickjames]

Can somone help me to find a section for requirements for open or closed risers for a spiral stairway in the 2018 IBC? It is in a dwelling unit in a R2 apartment building which it is allowed to be used as an means of egress from a small mezzanine.

2018 IBC

1011.5.5.3 Solid Risers​

Diagram
Risers shall be solid.
Exceptions:

1. Solid risers are not required for stairways that are not required to comply with Section 1009.3, provided that the opening between treads does not permit the passage of a sphere with a diameter of 4 inches (102 mm).
2. Solid risers are not required for occupancies in Group I-3 or in Group F, H and S occupancies other than areas accessible to the public. The size of the opening in the riser is not restricted.
3. Solid risers are not required for spiral stairways constructed in accordance with Section 1011.10.

 

[tbz]

Can somone help me to find a section for requirements for open or closed risers for a spiral stairway in the 2018 IBC? It is in a dwelling unit in a R2 apartment building which it is allowed to be used as an means of egress from a small mezzanine.

So,

• Section 1011.5.5.3 Solid Risers,
  • exception 3 exempts spirals per Section 1011.10
  • The question that has always been debated is do you also apply exception 1's, 4" sphere requirement or no sphere requirement at all.
    • The general consensus I have seen is none, because it is an MOE and the exception only applies to non-MOE.
• Section 1011.10 Spiral Stairways.
  • Allows a spiral as an MOE for "R"'s.....

2018 INTERNATIONAL BUILDING CODE (IBC) | ICC DIGITAL CODES

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org