NYC Building Code - 2008: Concrete Testing

1704.4 Concrete construction. The special inspections and verifications for concrete construction shall be as required by this section and Table 1704.4.

Exception: Special inspections shall not be required for the following when specifically exempted on the approved construction documents:

1. Concrete placement of less than 50 cubic yards (38 m³)‡ provided that the concrete is nonstructural and is not subject to the durability requirements of Section 1904. In such case, testing may be waived by the registered design professional who prepared the structural construction documents.

2. Nonstructural concrete slabs supported directly on the ground, including prestressed slabs on grade, where the effective prestress in the concrete is less than 150 psi (1.03 Mpa).

3. Concrete foundation(s) for lightweight fences and recreational equipment.

4. Concrete patios, site furnishings, garden walls, driveways, sidewalks and similar construction.

NYC Building Code 1968: Parapet Walls

§27-333 PARAPETS ON EXTERIOR WALLS.  Parapets shall be provided on all exterior walls of buildings of construction class II-A, II-B, or II-C that have roof construction of combustible materials.

§27-333(a) Exceptions.  A parapet need not be provided on the exterior wall of any building:

§27-333(a)(1) That is less than twenty-two feet high; or

§27-333(a)(2) Whose roof has a pitch of more than twenty degrees to the horizontal and whose overhang, fascia, cornice or gutter is of noncombustible construction, or if of combustible construction is separated from the roof and ceiling construction by construction having the fire-resistance rating required for the exterior wall of the building.  Combustible members, excluding roof sheathing and its supporting members, if covered by a class A roof covering and complying with the restrictions as required by section 27-335 of this article, shall not extend through this construction, but shall have at least four inches of solid noncombustible material below, at the sides, and at the ends of such members; or

§27-333(a)(3) That is provided with a fire canopy at, or not more than two feet below the roof level, continuous around that portion of the wall that is without a parapet, constructed as required by subdivision 27-331(f) of section 27-331 of this article.

§27-333(b) Construction.  Parapets required under this section shall be of materials and assembly having at least the fire-resistance rating of the wall below, and shall be at least two feet high.

NYC Building Code: Roof Reflectance Requirements

1504.8 Reflectance. Roof coverings on roofs or setbacks with slope equal to or less than three two units vertical in 12 units horizontal (25 17 percent) shall be white in color or EnergyStar rated as highly reflective for at least 75 percent of the area of the roof or setback surface. have:

1. A minimum initial solar reflectance of 0.7 in accordance with ASTM C 1549 or ASTM E 1918, and a minimum thermal emittance of 0.75 as determined in accordance with ASTM C 1371 or ASTM E 408; or

2. A minimum SRI of 78 as determined in accordance with ASTM E 1980.

Exceptions:

1. Terraces on setbacks comprising less than 25 percent of the area of the largest floor plate in the building.

2. Green roofs Any portion of a roof covered by a green roof system, including such a system with agricultural plantings, in compliance with Section 1507.16 shall be permitted to comprise part or all of the 75 percent required area coverage.

3. Roofs Any portion of a roof used as outdoor recreation space by the occupants of the building shall be permitted to be either that is landscaped, covered by wood decking or covered with a walking surface or other protective surface, provided that such walking surface or protective surface has with an albedo of 30 percent or greater a minimum initial solar reflectance of 0.3 as determined in accordance with ASTM C 1549 or ASTM E 1918.

4. Ballasted roofs, provided that the ballast has a minimum initial solar reflectance of 0.2 as determined in accordance with ASTM C 1549 or ASTM E 1918.

5. Any portion of a roof that is under mechanical equipment, flush mounted solar panels lying directly on the roof surface, duckboarding, decking, platform, roof tank, cooling tower or any other rooftop structure or equipment exempted by rule by the commissioner.

6. Any roof or portion of a roof composed of glass, metal, clay or concrete tile or plastic/rubber intended to simulate clay or concrete tile, wood, or slate.

7. Any portion of a roof used by a school or daycare center as a playground for children.

8. Any roof, if the amount of rooftop space not subject to exceptions 1 through 7 is in the aggregate less than 100 square feet (9.3 m²).

Stair Parts

NYC Building Code: Minimum Ceiling Heights

1208.2 Minimum ceiling heights. Habitable rooms and spaces shall have a ceiling height of not less than 8 feet (2438 mm). Occupiable spaces and corridors shall have a ceiling height of not less than 7 feet 6 inches (2286 mm). Bathrooms, toilet rooms, kitchens in other than I-1 and R occupancies, kitchenettes in I-1 or R occupancies, storage rooms and laundry rooms shall be permitted to have a ceiling height of not less than 7 feet (2134 mm). All measurements shall be taken from the finished floor to the finished underside of the ceiling or ceiling beams.

Exceptions:

1. In one- and two-family dwellings, beams or girders spaced not less than 4 feet (1219 mm) on center may project not more than 6 inches (152 mm) below the required ceiling height, provided that a clear height of 7 feet (2134 mm) is maintained.

2. Habitable rooms in basements of one-family dwellings, including any projecting beams, shall have a ceiling height of not less than 7 feet (2134 mm).

3. Habitable rooms in basements of multiple dwellings may have as many as four beams crossing the ceiling if none of the beams exceeds 12 inches (305 mm) in width or extends below the ceiling more than 6 inches (152 mm).

4. Spaces above and below a mezzanine, other than habitable spaces, shall have a ceiling height of not less than 7 feet (2134 mm).

NYC Occupiable & Habitable Space Defnitions

1202.1 General. The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein.

HABITABLE SPACE. All rooms and spaces within a dwelling unit in Group R or I-1, including bedrooms, living rooms, studies, recreation rooms, kitchens, dining rooms and other similar spaces.

Exception: The following spaces within a dwelling unit shall not be considered habitable spaces:

1. A dining space 55 square feet (5.1 m²) or less located off a living room, foyer or kitchen;

2. A kitchenette;

3. A bathroom or toilet room;

4. A laundry room; and

5. A corridor, passageway, or private hall; and a foyer used as an entrance hall in a dwelling unit: not exceeding 10 percent of the total floor area of the dwelling unit; or not exceeding 20 percent of the floor area of the dwelling unit where every habitable room is at least 20 percent larger than the required minimum room sizes established by the New York City Housing Maintenance Code.

KITCHEN. A room with 80 square feet (7.4 m²) or more of floor area which is intended, arranged, designed or used for cooking or warming of food.

KITCHENETTE. A space with less than 80 square feet (7.4 m²) of floor area which is intended, arranged, designed or used for cooking or warming of food.

OCCUPIABLE SPACE. A room or enclosed space, other than a habitable space, designed for human occupancy or use in which individuals may remain for a period of time for rest, amusement, treatment, education, dining, shopping, employment, labor or other similar purposes.

THERMALLY ISOLATED SUNROOM ADDITION. A one-story addition added to an existing building with a glazed area in excess of 40 percent of the gross area of its exterior walls and roof, with a separation of conditioned spaces, between such addition and a dwelling unit, consisting of existing or new wall(s), doors and/or windows.

The Jack Arch

Jack arch

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A jack arch is a structural element in masonry construction that provides support at openings in the masonry. Alternate names are "flat arch" and "straight arch".
Unlike regular arches, jack arches are not semicircular in form. Instead, they are flat in profile and are used under the same circumstances as lintels. Unlike lintels, which are subject to bending stress, jack arches are composed of individual masonry elements cut or formed into a wedge shape that efficiently uses the compressive strength of the masonry in the same manner as a regular arch. Like regular arches, jack arches require a mass of masonry to either side to absorb the considerable lateral thrust created by the jack arch.
Jack arches have the advantage of being constructed from relatively small pieces of material that can be handled by individuals, as opposed to lintels which must necessarily be monolithic and which must be oversized unless reinforced by other means.
In small-scale brick masonry projects, jack arches are typically sawn from an appropriately sized fired-clay lintel, giving a more precise and consistent joint width than field-sawn shapes.
There is considerable scope for incorporation of decorative patterns and elements into jack arches. Keystones, stepped or arched top profiles and polychrome or contrasting colors and materials may all be used to create the desired effect.

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