Tuesday, April 01, 2008

Scissor Stairs




Q: What is a Scissor Stair? When are Scissor Stairs permitted? Will Scissor Stairs still be permitted under the New NYC Construction Code?


A: A Scissor Stair is a set of 2 interlocking stairways providing two separate paths of egress located within one stairwell enclosure. The Stairs wind around each other, and are separated from each other within the enclosure, by fire rated construction having the same rating as the Stair Enclosure (usually 2-hour construction). Scissor Stairs are permitted under certain conditions by the New NYC Construction Code, as listed below.

Scissor stairs are particularly effective in small footprint Residential Apartment buildings requiring 2 vertical means of egress. In large footprint buildings, Scissor Stairs may create Dead End Corridors, and should be avoided.

Scissor Stairs are permitted in:

'J-2' Residential Apartment Buildings ('R-2' New Const Code).
Per New Construction Code Section 1014.2.1:




  • Stair doors must be at least 15 feet apart from each other


  • Stair Enclosing Walls shall be Constructed of 2-Hr rated Masonry or approved Masonry Equivalent material.


  • Stair may share common walls, floors, ceilings or scissor stairs assemblies or other enclosures provided that the construction separating the stairs is also of at least a 2-hour fire resistance rating and constructed of masonry or masonry equivalent.


  • Author’s Note: Comply with Dead End Corridor limitations.


  • Author’s Note: Both Stairs within the Scissor Stair enclosure must extend to the Roof to provide Roof Access.


  • Author’s Note: When both of the Stairs within a Scissor Stair terminate at a Street Floor Lobby, egress must be provided in 2 separate directions from the Lobby to the Street.



'E' Office Buildings ('B' New Const Code)
Per New Const Code Requirements Section 1014.2.1:




  • With a Building Height not exceeding 60 feet


  • With a Footprint not exceeding 2,000 sq ft per floor


  • Stair doors shall be at least 15 feet apart from each other


  • Maximum travel distance of 50 feet from most remote point to a Stair Door


  • Stair Enclosing Walls shall be Constructed of 2-Hr rated Masonry or approved Masonry Equivalent material


  • Stair may share common walls, floors, ceilings or scissor stairs assemblies or other enclosures provided that the construction separating the stairs is also of at least a 2-hour fire resistance rating and constructed of masonry or masonry equivalent.


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