Section 27-621. General construction requirements

The provisions of this
  section shall be considered as supplemental to  the  provisions  of  the
  applicable reference standards.
    (a)  Firecutting.  The ends of wood beams, joists, and rafters resting
  on masonry or concrete walls shall be firecut to a bevel of three inches
  in their depth.
    (b) Protection of members.
    (1) Positive drainage shall  be  provided  for  all  areas  under  the
  building not occupied by basements or cellars.
    (2) All loose wood and debris and all wood forms shall be removed from
  spaces  under  the  building. All stumps and roots shall be grubbed to a
  minimum depth of twelve inches.
    (3) Wood members embedded in the ground and used for  the  support  of
  buildings shall be treated.
    (4) Wood joists or wood structural floors closer than eighteen inches,
  wood  girders  closer  than  twelve  inches,  or sills closer than eight
  inches to an exposed ground surface within or without the building shall
  be treated or shall be of an equivalent resistant species.
    (5) Sleepers, sills, columns,  and  posts  supported  on  concrete  or
  masonry  piers  shall  be treated or shall be of an equivalent resistant
  species unless isolated from the ground as specified in  paragraph  four
  of  this subdivision or by a concrete slab. Where the isolation consists
  of a concrete slab-on-grade, the  sleepers,  sills,  columns,  or  posts
  shall be raised at least three inches above the top of such slab.
    (6)  Ends  of wood girders entering masonry or concrete walls shall be
  provided with a minimum one-half inch air space on top,  sides,  and  at
  the  end,  unless the girder is treated or is of an equivalent resistant
  species.
    (7) Wood or plywood used as siding or  a  combination  of  siding  and
  sheathing shall be isolated from exposed ground by at least six inches.
    (8)  Crawl spaces shall be ventilated as required in subchapter twelve
  of this chapter.
    (9) Where treated timber is required, the preservative treatment shall
  comply with reference standards RS 10-20 and RS 10-22. Treatment of wood
  poles shall comply with reference standard RS 10-28.  All  treated  wood
  shall be handled in accordance with the provisions of reference standard
  RS 10-29.