N.Y.C. Admin. Code § BC 1510: Section BC 1510: Rooftop Structures

1510.1 General.

The provisions of this section shall govern the construction of rooftop structures. All rooftop structures shall be subject to the roof area coverage limitations and building height requirements of Chapter 5. Rooftop structures shall be constructed with materials as required for the building, except as provided for in this section.

1510.2 Bulkheads and penthouses.

Bulkheads and penthouses shall comply with the construction requirements of section.

1510.2.1 Type of construction.

Bulkheads and penthouses shall be constructed with walls, floors and roof as required for the building.

Exceptions: Where the total aggregate area of all rooftop structures does not exceed 33 percent of the area of the roof of the building upon which they are erected, the following shall apply:

1. Bulkheads on buildings of Type I and II construction. The exterior walls and roofs of such bulkheads with a fire separation distance of more than 5 feet (1524 mm) and less than 30 feet (9144 mm) shall be of at least 1-hour fire-resistance-rated noncombustible construction. Walls and roofs with a fire separation distance of 30 feet (9144 mm) or greater shall be of noncombustible construction. Interior framing and walls shall be of noncombustible construction.

2. Bulkheads on buildings of Type III, IV and V construction. The exterior walls of such bulkheads with a fire separation distance of more than 5 feet (1524 mm) and less than 30 feet (9144 mm) shall be at least 1-hour fire-resistance-rated construction. Walls with a fire separation distance of 30 feet (9144 mm) or greater from a common property line shall be of Type IV construction, or noncombustible construction. Roofs shall be constructed of materials and fire-resistance rated as required in Table 601. Interior framing and walls shall be Type IV or noncombustible or fire-retardant-treated wood construction.

1510.2.2 Penthouses.

Enclosed walls of penthouses shall comply with the requirements for exterior walls as per Tables 601 and 602 for the construction class of the building on which they are erected. Roofs of penthouses shall comply with the requirements for roof construction of Table 601 and Chapter 15 of this code.

1510.2.3 Bulkheads.

An enclosed rooftop structure not intended for human occupancy shall not be used for purposes other than shelter of mechanical equipment or shelter of vertical shaft openings in the roof. Provisions, such as louvers, louver blades or flashing, shall be made to protect the mechanical equipment and the building interior from the elements.

1510.3 Tanks.

Tanks having a capacity of more than 500 gallons (1892.7 L) located on the roof deck of a building shall be supported on masonry, reinforced concrete, steel or Type IV construction provided that, where such supports are located in the building above the lowest story, the support shall be fire-resistance rated as required for Type IA construction.

1510.3.1 Valve and drain.

On the bottom or on the side near the bottom of the tank, a pipe or outlet, fitted with a suitable quick-opening valve for discharging the contents into a drain in an emergency shall be provided.

1510.3.2 Location.

Tanks shall not be placed over or near a stairway or an elevator shaft, unless there is a solid roof or floor underneath the tank.

1510.3.3 Tank cover.

Unenclosed roof tanks shall have covers sloping toward the perimeter of the tanks.

1510.4 Cooling towers.

Cooling towers shall be of noncombustible construction.

Exceptions:

1. Fill and drift eliminators of limited combustible materials may be considered noncombustible if the cooling towers are provided with automatic sprinkler protection complying with Section 903.

2. Fill and drift eliminators that comply with Section 908 of the New York City Mechanical Code.

1510.5 Steeples, minarets, spires, domes and cupolas.

Steeples, minarets, spires, domes, cupolas and other similar architectural elements not used for occupancy or storage, shall be constructed of materials consistent with the required type of construction of the building and shall be of a type of construction having fire-resistance ratings not less than required for the building on top of which such steeple, minaret, spire, dome or cupola is built.

1510.5.1 Noncombustible construction required.

Steeples, minarets, spires, domes and cupolas greater than 60 feet (18 288 mm) in height above the highest point at which such structure contacts the roof as measured to the highest point on such structure, or that exceeds 200 square feet (18.6 m

2

) in area at any horizontal section, or which is intended to be used for any purpose other than as a belfry or architectural embellishment, or is located on the top of a building greater than 50 feet (1524 mm) in building height shall be constructed of and supported by noncombustible materials and shall be separated from the building below by construction having a fire-resistance rating of not less than 1.5 hours with openings protected in accordance with Section 712. Such structures located on the top of a building greater than 50 feet (15 240 mm) in building height, shall be supported by noncombustible construction.

1510.5.2 Steeples, minarets and spires.

Steeples, minarets, and spires shall have exterior walls constructed as required for the building on top of which such steeples, minarets and spires are built. The roof covering of spires shall be not less than the same class of roof covering required for the building on top of which the spire is located.

1510.6 Dormers.

Dormers shall have exterior walls as required for the building to which they are attached. The roof covering of dormers shall be of a class of roof covering as required for the main roof of the rest of the structure.

1510.7 Greenhouses.

Greenhouses used for the cultivation of plants, on the roofs of buildings other than buildings of Type V construction, shall be constructed of noncombustible framework and shall be glazed with plain or wire glass, or light transmitting plastic glazing complying with the requirements of Section 2606. The floors of greenhouses shall be constructed to be at least equal to the requirements for roof construction on Table 601 for the construction class of the building on which it is located.

1510.8 Protective guards.

Buildings greater than 22 feet (6706 mm) in height with roof slopes less than 2.4 units vertical in 12 units horizontal (20-percent slope) shall be provided with a parapet, guards, fence, or combination thereof, not less than 42 inches (1067 mm) in height. Guards or fences may be located inward from the face of the exterior wall a distance not exceeding 6 feet (1828.8 mm). Guards or fences shall be of noncombustible material, except on buildings of Type V construction. Guards shall be constructed to comply with the requirements of Sections 1015 and 1607.8.

1510.8.1 Fences on roofs used for recreational purposes.

Rooftops used for recreational purposes shall be provided with wire fencing at least 10 feet (3048 mm) in height. Openings in the fence shall not permit the passage of a 4-inch (101.6 mm) diameter sphere. Where ball games are played on rooftops the wire fencing shall be extended to provide an overhead closure.

1510.9 Miscellaneous combustible roof structures.

The following roof structures may be constructed of combustible material if less than 12 feet (3657.6 mm) high above the roof: antenna supports; flagpoles; clothes drying frames; duckboarding; decking or platforms that do not cover more than 20 percent of the contiguous roof area at that level.

1510.10 Mechanical equipment screens.

Mechanical equipment screens shall be constructed of the materials specified for the exterior walls in accordance with the type of construction of the building.

1510.10.1 Type V construction.

The height of mechanical equipment screens located on the roof decks of buildings of Type V construction, as measured from grade plane to the highest point on the mechanical equipment screen, shall be permitted to exceed the maximum building height allowed for the building by other provisions of this code where complying with any one of the following limitations, provided the fire separation distance is greater than 5 feet (1524 mm):

1. Where the fire separation distance is not less than 20 feet (6096 mm), the height above grade plane of the mechanical equipment screen shall not exceed 4 feet (1220 mm) more than the maximum building height allowed;

2. The mechanical equipment screen shall be constructed of noncombustible materials;

3. The mechanical equipment screen shall be constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation; or

4. Where the fire separation distance is not less than 20 feet (6096 mm), the mechanical equipment screen shall be constructed of materials having a flame spread index of 25 or less when tested in the minimum and maximum thicknesses intended for use with each face tested independently in accordance with ASTM E 84 or UL 723.

1510.11 Photovoltaic systems.

Rooftop mounted photovoltaic systems shall be designed in accordance with this section.

1510.11.1 Wind resistance.

Rooftop mounted photovoltaic systems shall be designed for wind loads for component and cladding in accordance with Chapter 16 using an effective wind area based on the dimensions of a single unit frame.

1510.11.2 Fire classification.

Rooftop mounted photovoltaic panels and modules shall have the fire classification in accordance with Section 1505.9.

1510.11.3 Installation.

Rooftop mounted photovoltaic panels and modules shall be installed in accordance with the manufacturer's instructions.

1510.11.4 Photovoltaic panels and modules.

Photovoltaic panels and modules mounted on top of a roof shall be listed and labeled in accordance with UL 1703 and shall be installed in accordance with the manufacturer's instructions.