Evening bulletin., 1911-06-09
STEEL FRAME CONSTRUCTION.
STEEL.

| W 'oNHs III "hs oNttl vi ftSS
than one-thirty-second Of its unsup-
ported width, measured between CEN
ters Of rivets transversely, or one
sixteenth of the distance between
centers of rivets In the direction of
the stress.
OBJ The ends of all columns shall
be faced to plane surface at right
angles TO the axis of the column,
and the connections between them
shall be made with splice plates near
and above the floor line.
tc) Steel and wrought-iron col
umns may be made in one, two, and
three-story lengths.
ROLLED STEEL BEAMS.
Section a. All rolled-steel beams
used in buildings shall be of full
weight and free from injurious de-
fects.
CONNECTIONS.
Section 25. All steel and iron franz
ing shall have shop and field connec-
tions made by rivetirE, II possible.
When rHeting is not possible, field
connections may be made with bolts.
RlvETING OF STRUCTURAL STEEL
AND WROUGHT IRON WORK.
Section &C. The distance from
center of rivet hole to the edge of
the piece shall not be less than one
and one-half times the diameter Of
the rivet. Wherever possible, how
ever, the distance should be equal to
two diameters. When practicable,
rivets shall be machine driven. The
pitch OF rivets shall never he less
than three diameters of the rivet nor
more than inches.
STEEL TRUSSES.
Section 27.--Trusses shall be of
such design that there will be no un-
certainty in the stresses. All trusses
shall be held rigidly in position by
efficient systems of lateral and sway
braciDg.
WALL PLATES.
Section 2S.-Bearing plates of stone
or metal shall be used to reduce The
pressure on bearing wall TO the
allowable working stress.
BRACING OF FRAMES.
Section 20. The iron or steel frame
OF any building shall be carried up
true and plumb and be rigidly braced
from the floor beams of every story
CAST IRON COLUMNS.
Section 30. In computing the
strength Of cast-iron column Its
thickness shall be taken at It's thinneBt
part, and the column shall be con-
demned II the computation shows that
the strength of the piece be less than
required by these regulations. Wher-
ever blowholes or imperfections are
found in cast-iron column which
reduces the area OF the cross-section
at the point more than ten per
centum, such column shall be con-
demned Cast-iron posts or columns
without one side or back open, before
being set in place, may at the option
Of the Building Inspector be drilled
to exhibit to the Inspector the thick
ness of the metal. Such hole shall
be drilled, under the supervision Of
the Inspector, by and at the expense
of the owner or contractor
PAINTING OF STRUCTURAL
METAL WORK.
Section 81. All structural metal
work shall be cleaned Of all scale,
dirt, and rust and except when em-
bedded in cement or concrete shall
be thoroughly, coated with at least
one coat of nonoxidizing paint before
leaving the shop or before erection.
After erection, all places left for shop
marks, all abrasions, and all rivet
heads and bolts shall be painted.
after which the entire frame shall be
painted with at least one additional
coat of tint different from the first.
All iron or steel used below the
ground water level shall be inclosed
by Portland cement concrete.
SKELETON FRAME.
PROPoRTIoNING OF FRAME.
Section 32. In proportioning the
skeleton frame each part shall be con-
structed of sufficient strength to carry
the superimposed load without assist
ance from the walls below Girders for
the support Of inciosing walls shall
be placed at the level Of the floors
Irregular or eccentric loading shall
be avoided as far as possible.
FLOOR SYSTEM,
Section 33. The floor system OF a
skeleton frame shall be constructed
with steel or reinforced concrete
floor beams, so designed that tho, max
imum load imposed shall not cause
a greater DETECTION than one three
hundred-sixtieth part OF the span
The floor beams shall be tied together
at intervals not exceeding eight
times the depth of the beams by SUIT
able ties or other approved method.