143 - Construction of first floor.

§  143.  Construction  of  first  floor.  1. The first floor above the  lowest cellar, or, if there be no cellar, above the lowest story,  shall  be  fireproof  or,  if  the dwelling be three stories or less in height,  fire-retarded. Said first floor shall be unpierced except  for  a  stair  leading to a cellar as provided in section one hundred fifty, for lawful  pipes,  conduits  and  ducts and for dumbwaiter and elevator shafts. Any  such dumbwaiter and elevator shafts shall be equipped  at  all  openings  below  the said first floor with fireproof doors and assemblies with the  doors self-closing.    2. Whenever the lowest cellar does not extend over more than half  the  area of the dwelling, that portion of the first floor directly over such  cellar   and  the  entire  second  floor  above  such  cellar  shall  be  constructed as in this section prescribed for the first floor above  the  lowest  cellar.  Whenever the lowest cellar extends over more than half,  but not all, of the area of the dwelling, only that portion of the first  floor directly over such cellar need be constructed as in  this  section  prescribed for the first floor above the lowest cellar.