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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Fire Escapes as a Means of Egress?

Picture of a Fire Escape on an existing Multiple Dwelling

Q: Are FIRE ESCAPES permitted as a second Means of Egress on New or ALTERED Buildings?

A: As per Building Code Section 27-368, the use of Fire Escapes as a second Means of Egress is very limited:

-Fire Escapes are not permitted on New Buildings, with the exception of GROUP HOMES.

-Fire Escapes may be used as exits on buildings that existed on 12/6/1968, when such buildings are Altered, but only with the approval of the DOB Commissioner (sounds like the topic of a RECONSIDERATION)

When an existing building relies on a FIRE ESCAPE as a second Means of Egress, the Fire Escape needs to be retained, unless the building's egress is upgraded in such a way that the Fire Escape is no longer required (for instance, if an additional, compliant INTERIOR STAIR were installed to serve as a second Means of Egress).

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Tags: fire escape, egress, exit, multiple dwelling

Roof Access for Interior Stairs

Q: When is it required for INTERIOR STAIRS to provide Roof Access?

A: Interior Stairs shall provide Roof Access as follows:

-At least one Interior Stair shall provide Roof Access in buildings or building sections greater than 3 stories or 40' high, when the roof has a slope of less than twenty degrees. Access to setback roof areas may be through a door or window opening to the roof. Interior stairs extending to roofs shall be enclosed in bulkheads of fire-resistant construction.

-All Interior Stairs in buildings classified in J-1 (Transient Residential) or J-2 (Permanent Residential, 3 or more Dwelling Units), which are more than 2 stories in height, with a roof having a slope of 15 degrees or less, shall provide Roof Access, except where the Stair terminates at a Setback Roof. Stairs shall extend to the roof in bulkheads of fire-resistive construction. Stairs terminating at the level of a setback roof shall provide access to the setback roof areas through a door except where the setback is less than 4' in width and less than 10' in length, as measured from the inside of the parapet wall.

-In buildings or in building sections classified in occupancy group J-1 two stories in height and in occupancy group J-2 three stories in height with not more than one dwelling unit per story with roofs having a slope of fifteen degrees or less, access to the roof shall be provided through a scuttle at least 21" in width and 28" in length. Scuttles shall be located within each stair enclosure with a stationary iron ladder leading to them.

Reference 1968 NYC Building Code Section: 27-375(k) for full details

Stairs with Handrails on Both Sides?

Q: For an Exit Stair, when is it necessary to provide Handrails on both sides?

A: Stairs 44 inches wide and wider require a handrail on both sides. Stairs narrower that 44 inches only require a handrail on one side.

Stairs more than 88 inches wide need intermediate handrails dividing the stair into widths not greater than 88 inches nor less than 44 inches.

This is as per BC Section §27-375(f)

Fire Separations for Cellar Stairs

Q: Do Cellar Stairs need to be fire-separated from Stairs serving upper floors of the building?

A: Yes, Cellar Stairs need to be fire-separated from stairs serving upper-floors of the building, with a minimum of 1-hour fire rated construction and a 3/4-hr fpsc door. Except that this separation is not required in J-3 Residential Buildings (One- or Two-Family Dwellings), and in G-School (Educational) Buildings. Refer to Building Code Section 27-364-Exit Discharge for the exact wording/requirements

Stair Landings?

Q: What is the minimum required size of a Stair Landing for an Egress/Exit Stair? Where are Stair Landings required? What is the maximum vertical rise of a Stair before Intermediate Landings are required?

A: Below are some paraphrased Code Sections answering these questions:

1. Stair Landings and Platforms shall be provided at the head and foot of each flight of stairs, except at the head of a basement stair in one- and two-family dwellings.

2. The minimum width of stair landings and platforms perpendicular to the direction of egress shall be equal to at least the width of the stair.

3. Intermediate landings need not be more than 44" wide.

4. The maximum vertical rise of a single flight of stairs shall not exceed:

• 8' in Occupancy Group F (Place of Assembly) and H (Hospital, Nursing Home, Mental Institution, Jail)

• 12' in all other Occupancy Groups.

Provide an Intermediate Landing where the vertical rise exceeds these distances.

4. The swing of stair doors shall not block stairs or stair landings.

5. The swing of a Stair Door shall not reduce the clear width of the Stair landing to be less than seventy-five percent of the required width of the landing or stair.

6. The swing of a Stair Door shall not reduce the clear width of the Stair landing to be less than the width of the door opening on them.

See BC Section 27-375(d) and 27-375(g) for the exact wording/additional details

Spiral Stairs?

Q: Are Spiral Stairs permitted as an interconnecting stair in Vertical Duplex Apartments?

A: Per BC Section 27-375(l). Spiral stairs may be used as an interconnecting stair in a Duplex Apartment. They should have at least 30" long treads. Per the below, spiral stairs do not count towards required exits. However, if the connected floor were a mezzanine and the stair was non-combustible, you might get it accepted as a means of egress under a Recon. You need to comply with the Duplex Apt Memo as well.

BC Section:
Spiral stairs may serve as access stairs between two floors or levels in accordance with the provisions of paragraph two of subdivision (i) of this section.

Such stairs may not serve as required exits, except that unenclosed spiral stairs when built of noncombustible materials and having a tread length of at least thirty inches may serve as exits from mezzanines or balconies having an occupant load not exceeding twenty-five persons.

Are Exit Signs Required in Residential Apartment Buildings?

Q: Are Exit Signs required at each floor in Residential Apartment Buildings or One-or Two-Family Residences?

A: No. Per BC Section 27-383, the Code makes an exception in the Exit Sign Requirement for Apartment Buildings (J-2) and One- or Two-Family Residences. Exit Signs are not required at each floor in J-2 or J-3 Buildings. See below Code Section:
"§27-383 REQUIREMENTS. Except in occupancy groups J-2 and J-3, the location of every exit on every floor and every opening from a room classified in occupancy group J-1 and containing cubicles shall be clearly indicated by exit signs. Such signs shall be placed at an angle with the exit opening if such placement is required for the signs to serve their purpose. In long corridors, in open floor areas, and in all other situations where the location of the exit may not be readily visible or understood, directional signs shall be provided to serve as guides from all portions of the corridor or floor."