Section 27-623. Heavy timber construction (construction class II-A)

(a)
  Minimum sizes of members. To  conform  to  the  fire  resistance  rating
  requirements  for  heavy  timber construction (construction class II-A),
  members shall be solid sawn or solid glue-laminated and of the following
  minimum dimensions: (Sizes of wood members indicated in this section are
  nominal sizes).
    (1) COLUMNS, FRAMES AND ARCHES.
    a. Columns shall be at least  eight  inches  in  all  dimensions  when
  supporting  floor  loads,  and at least six inches wide and eight inches
  deep when supporting roof and ceiling loads only.
    b. Beams and girders shall be at least six inches wide and ten  inches
  deep.
    c.  Frames  or  arches  that  spring  from grade or the floor line and
  support floor loads shall be at least eight inches in all dimensions.
    d. Timber trusses supporting floor loads shall have members  at  least
  eight inches in all dimensions.
    e.  Frames  or  arches for roof construction that spring from grade or
  the floor line and do not support floor  loads  shall  have  members  at
  least  six  inches  wide and eight inches deep for the lower half of the
  height, and at least six inches deep for the upper half.
    f. Frames or arches for roof construction that spring from the top  of
  walls  or wall abutments, framed timber trusses, and other roof framing,
  which do not support floor loads,  shall  have  members  at  least  four
  inches  wide  and six inches deep. Spaced members may be composed of two
  or more pieces at least three inches thick when blocked solidly  through
  their  intervening  spaces  or  when such spaces are tightly closed by a
  continuous wood cover plate at least two inches  thick  secured  to  the
  underside  of  the members. Splice plates shall be at least three inches
  thick. When protected by approved automatic sprinklers  under  the  roof
  deck, framing members shall be at least three inches wide.
    (2) FLOORS.
    a.  Planks  shall be splined or tongue-and-groove, not less than three
  inches thick, covered with one  inch  tongue-and-groove  flooring,  laid
  crosswise or diagonally to the plank, or other surface having equivalent
  fire resistance; or shall be,
    b.  At  least  four  inches  wide, set on edge close together and well
  spiked, and covered the same as for three inch thick plank.  The  planks
  shall  be  laid so that there is no continuous line of end joints except
  at points of support. Floors shall not extend closer than one-half  inch
  to  walls  to provide an expansion joint, but the joint shall be covered
  at top or bottom to avoid flue action.
    (3) ROOF DECKS. Roof  decks  shall  be  splined  or  tongue-and-groove
  planks  at  least  two inches thick; or tongue-and-groove plywood panels
  (bonded with exterior glue) at least one and one-eighth inch thick, with
  face grain perpendicular to supports that shall be spaced not more  than
  forty-eight  inches  on  center; or of planks at least three inches wide
  set on edge close together and laid as required for floors.
    (b) Construction details. Self releasing  type  wall  plate  boxes  or
  approved  hangers  shall  be  provided  where  beams  and  girders enter
  masonry.
 
           (For Table 10-4 see chapter 839  of the  laws of 1986)
 
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     2                                                            |
     3          COPY OF Chapter 839 of the laws of 1986           |

     1          MAY BE OBTAINED FROM:                             |
     2          NYS LEGISLATIVE BILL DRAFTING COMMISSION          |
     3          CONTACT: LEGISLATIVE RETRIEVAL SYSTEM'S HELPLINE  |
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