N.Y.C. Admin. Code § 27-868: § 27-868 Smoke test.

(a) General. When required by the commissioner to determine the tightness of chimney construction, a smoke test shall be made in accordance with the following conditions and requirements:

(1) The equipment, materials, power and labor necessary for such test shall be furnished by, and at the expense of, the owner or holder of the work permit.

(2) If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the requirement of this subchapter and the test shall be repeated until the results are satisfactory.

(b) Method of test. The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke bombs, or other equivalent method. As the smoke appears at the stack opening on the roof, such opening shall be tightly closed and a pressure equivalent to one-half inch column of water measured at the base of the stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspection of the chimney.