2006 New York Code - Ground Signs.

 
    § 27-500 Ground signs. (a) Location. No part of a ground sign shall be
  erected  so as to project beyond the street line, except as specifically
  permitted by the provisions of subchapter four of this chapter.
    (b) Materials. Inside  the  fire  districts,  ground  signs  shall  be
  constructed entirely of noncombustible materials, except as permitted in
  sections  27-506 and 27-507 of this article. Outside the fire districts,
  the structure of ground signs exceeding twenty-five hundred square  feet
  in  facing  or  display  area  shall  be  constructed  of noncombustible
  materials, and the facing of such signs shall be noncombustible,  except
  as  permitted  in sections 27-506 and 27-507 of this article. The bottom
  of the facing of all ground signs shall be at least thirty inches  above
  the  ground,  which  space  may  be  filled  with  open  lattice work or
  decorative trim.
    (c) Supports. Ground signs shall be constructed and anchored to resist
  loads acting in any direction  on  the  sign,  in  accordance  with  the
  provisions of subchapter nine of this chapter.
    (1)  Anchors  and supports shall be designed for safe bearing loads on
  the soil and for an effective resistance to pullout amounting to a force
  twenty-five  per  cent  greater  than   the   required   resistance   to
  overturning. Anchors and supports shall penetrate to a depth of at least
  four feet.
    (2) Whenever anchors or supports consist of wood embedded in the soil,
  the  wood  shall  be  treated  under pressure as specified in subchapter
  eleven of this chapter before erection. This requirement shall not apply
  to signs which are not to remain in place for more than six months.
    (3) Members furnishing structural support for signs shall be  designed
  in  accordance  with the requirements of subchapter ten of this chapter,
  and shall be of adequate thickness to meet the corrosion conditions.