§ 241. Partitions; fire-stopping. 1. In tenements erected after April
eighteenth, nineteen hundred twelve, wood stud apartment partitions
which are directly over each other shall run through the wood floor
beams and rest upon the plate of the partition below. In fireproof
tenements erected after such date all partitions shall rest directly
upon the fireproof floor construction and extend to the fireproof beam
filling above. Apartment partitions within the meaning of this section
are partitions crossing the floor beams at any angle and separating one
apartment from another or any part of an apartment from any public part
of the dwelling.

2. In tenements erected after April eighteenth, nineteen hundred
twelve, apartment studding shall be filled in solidly between the
uprights to the depth of the floor beams with incombustible materials.

3. In non-fireproof tenements erected after April twelfth, nineteen
hundred one, in every wall where wood furring is used, every course of
masonry from the under side to the top of any floor beams shall project
a distance of two inches or more beyond each face of the wall that is
not on the outside of the dwelling, so as to provide an effective fire
stop; and whenever floor beams run parallel to a wall and wood furring
is used, every such beam shall always be kept two inches away from the
wall, and the space between the beams and the wall shall be built up
solidly with brickwork from the underside to the top of the floor beams
so as to form an effective fire stop.