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 (e) Primary members including frames and other main load
carrying members shall consist of hot-rolled structural shapes having
"I"-shape of constant depth or structural tubing while secondary structural
miscellaneous secondary framing shall consist of either hot-rolled or
cold-formed structural steel. All primary members and main secondary
members (purlins, girts, etc.,) shall be formed from symmetrical "I"
sections.
(f) Primary structural framing connections shall be either shop
welded or bolted or field bolted assemblies. ASTM A325 bolts with
appropriate nuts and washers shall be used for connecting of all primary
members; where as secondary members may use bolts conforming to ASTM A307.
A minimum of two bolts shall be used for each connection while bolts for
primary and secondary members shall not be less than 3/4- and 1/2-inch in
diameter, respectively.
(g) Base plates for columns shall be rolled and set on grout
bed of 1-inch minimum thickness. ASTM A307 steel bolts shall be used to
anchor all columns.
(2) Concrete. Concrete floor and foundation slabs shall be
monolithic in construction and shall be designed to transfer all horizontal
and vertical loads, as described below, from the pre-engineered
superstructure for the foundation soil.
(3) Roof and Wall Coverings.
(a) Roof and wall coverings shall conform to ASTM A 446, G 90,
have a corrugation minimum depth of 1-1/2 inches, and have a material
thickness of 22 gauge.
(b) Side laps of coverings shall overlap by a minimum of 2-1/2
corrugations. End laps, if required, shall occur at structural steel
supports and have a minimum overlap of 12 inches.
(c) Insulation retainers or sub girts shall be designed to
transmit all external loads (listed below) which act on the metal cover to
the structural steel framing.
(d) Roof and wall liners shall be a minimum of 24 gauge and
shall be formed to prevent waviness, distortion or failure as a result of
the impact by external loads.
(e) Fasteners for connecting roof and wall coverings to
structural steel supports shall be designed to support the external loads
(listed below) and shall consist of either self-tapping screws,
self-drilling and self-tapping screws, bolts and nuts, self-locking rivets,
self-locking bolts, end welded studs, or welds. Fasteners of covering to
structural steel shall be located at valleys of the covering and shall have
a minimum of one fastener per valley.
(f) Fasteners which do not provide positive locking such as
self-tapping screws, etc. shall not be used at side laps and for fastening
accessories to panels. At least one fastener for side laps shall be located
in each valley and at a maximum spacing along the valley of 8 inches.
2.08-239
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