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What is NYC BC § 509.4.2?

Quick Answer

This section outlines the requirements for protecting incidental uses in buildings with automatic sprinkler systems. It mandates that these areas be separated by smoke-resistant construction and specifies the design and functionality of doors, including self-closing mechanisms and restrictions on air transfer openings. Applies to building owners implementing fire safety measures.

General informational summary. Not legal advice for your situation. Consult an attorney before acting on any specific matter.

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509.4.2 Protection.

BC § 509.4.2

Where Table 509 permits an automatic sprinkler system without a fire barrier, the incidental uses shall be separated from the remainder of the building by construction capable of resisting the passage of smoke. The walls shall extend from the top of the foundation or floor assembly below to the underside of the ceiling that is a component of a fire-resistance-rated floor assembly or roof assembly above or to the underside of the floor or roof sheathing, deck or slab above. Doors shall be self- or automatic-closing upon detection of smoke in accordance with Section 716.5.9.3. Doors shall not have air transfer openings and shall not be undercut in excess of the clearance permitted in accordance with NFPA 80. Walls surrounding the incidental use shall not have air transfer openings unless provided with smoke dampers in accordance with Section 710.8.

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