N.Y.C. Admin. Code § BC 2104: Section BC 2104: Construction

2104.1 Masonry construction.

Masonry construction shall comply with the requirements of Sections 2104.1.1 through 2104.10, TMS 402, and TMS 602 or TMS 604.

2104.1.1 Lintels.

Minimum length of end support shall be 4 inches (102 mm).

2104.1.2 Support on wood.

Masonry shall not be supported on wood girders or other forms of wood construction except as permitted in Section 2304.12.

2104.1.3 Projecting masonry and cornices.

Unless structural support and anchorage are provided to resist the overturning moment, the center of gravity of projecting masonry or molded cornices shall lie within the middle one-third of the supporting wall. Terra cotta and metal cornices shall be provided with a structural frame of approved noncombustible material anchored in a manner approved by the commissioner.

2104.2 Cold weather construction.

The cold weather construction provisions of Article 1.8 C of TMS 602 shall be implemented when either the ambient temperature falls below 40°F (4°C) or the temperature of masonry units is below 40°F (4°C).

2104.2.1 Preparation.

No salt or other chemicals for the purpose of lowering the freezing temperature of water shall be permitted in the mortar or grout mix.

2104.3 Hot weather construction.

The hot weather construction provisions of Article 1.8 D of TMS 602 shall be implemented when the temperature exceeds 100°F (37.8°C), or 90°F (32.2°C) with a wind-velocity greater than 8 mph (12.9 km/hr).

2104.4 Wetting of brick.

Brick (clay or shale) at the time of laying shall require wetting if the unit's initial rate of water absorption exceeds 21.42 grams per 30 square inches (19 355 mm

2

) per minute or 0.025 ounce psi (1 g/645 mm

2

), as determined by ASTM C 67.

2104.5 Masonry construction bracing.

In accordance with Article 3.3E of TMS 602, the contractor shall design, provide, and install bracing that will assure stability of all masonry during construction. The contractor shall keep a bracing plan on site during all masonry construction. Bracing plans shall consider wind loads, initial and intermediate masonry strengths, and the contractor's ability to evacuate the site. Construction bracing for walls within a distance less than their height from adjoining properties or other unprotected and uncontrolled areas shall be designed for code prescribed wind loads and the bracing plan shall be signed and sealed by a licensed professional engineer. Construction bracing for walls may be designed using reduced loading in accordance with Section 1619. Such reduced loading shall only be permitted when an action plan meeting the requirements of Section 1619.3 is provided and maintained at the site.

2104.6 Parapet walls.

At a minimum, parapet walls shall meet the following requirements:

2104.6.1 Parapet wall construction.

All cells in the hollow masonry units and all joints in solid, cavity, or masonry-bonded hollow wall construction shall be filled solid. All corners of masonry parapet walls shall be reinforced with joint reinforcement or its equivalent at vertical intervals not greater than 16 inches (406 mm). Such reinforcement shall extend around the corner for at least 4 feet (1219 mm) in both directions, and splices shall be lapped at least 6 inches (152 mm).

2104.6.2 Parapet anchorage.

Parapets shall be reinforced vertically and shall be anchored to the roof and floors that provide lateral support for the wall in accordance with Section 1604.8.2.

2104.7 Floor and roof anchorage.

Floor and roof anchorage shall comply with Section 2104.7.1 through 2104.7.1.3.

2104.7.1 Bearing details.

Concentrated loads shall be supported upon construction of solid masonry, concrete, or masonry of hollow units with cells filled with mortar, grout, or concrete. In addition, construction supporting concentrated loads shall be of sufficient height to distribute safely the loads to the wall or column, or other adequate provisions shall be made to distribute the loads.

2104.7.1.1 Joists.

Solid construction for support under joists shall be at least 2 1/4 inches (57 mm) in height, and joists supported on such construction shall extend into the masonry at least 3 inches (76 mm).

2104.7.1.2 Beams.

Solid construction for support under beams, girders, or other concentrated loads shall be at least 4 inches (102 mm) in height, and the bearing of beams shall extend into the masonry at least 4 inches (102 mm).

2104.7.1.3 Isolated piers.

Isolated masonry piers shall be bonded as required for solid walls of the same thickness and shall be provided with adequate means for distributing the load at the top of the pier.

2104.8 Walls adjoining structural framing.

Walls adjoining structural framing shall comply with Sections 2104.8.1 and 2104.8.2.

2104.8.1 Use of existing walls.

An existing masonry wall may be used in the alteration or extension of a building provided that it meets the requirements of this code.

2104.8.2 Walls of insufficient thickness.

Existing walls of masonry units that are structurally sound, but that are of insufficient thickness when increased in height, may be strengthened by an addition of similar masonry units laid in Type M or S mortar. The foundations and lateral support shall be equivalent to those required for newly constructed walls under similar conditions. All such linings shall be thoroughly bonded into existing masonry by toothings to assure combined action of wall and lining. Toothings shall be distributed uniformly throughout the wall, and shall aggregate in vertical cross-sectional area at least 15 percent of the total surface area of the lining. Stresses in the masonry under the new conditions shall not exceed the allowable stresses.

2104.9 Isolation joints.

All non-participating masonry walls and veneers shall be constructed with adequate depth and width of isolation joints to prevent masonry distress induced by deflections, drifts, shortening, expansion, or other similar movements in the plane of the wall.

2104.10 Substitution.

Mortar shall not be substituted for grout where grout is specified on the construction documents.